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The race to zero emissions, and why the world depends on it

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A host of countries have recently announced major commitments to significantly cut their carbon emissions, promising to reach "net zero" in the coming years. The term is becoming a global rallying cry, frequently cited as a necessary step to successfully beat back climate change, and the devastation it is causing.

What is net zero and why is it important?

Put simply, net zero means we are not adding new emissions to the atmosphere. Emissions will continue, but will be balanced by absorbing an equivalent amount from the atmosphere.

Practically every country has joined the Paris Agreement on climate change, which calls for keeping the global temperature to 1.5°C above pre-industrial era levels. If we continue to pump out the emissions that cause climate change, however, temperatures will continue to rise well beyond 1.5, to levels that threaten the lives and livelihoods of people everywhere.

This is why a growing number of countries are making commitments to achieve carbon neutrality, or "net zero" emissions within the next few decades. It’s a big task, requiring ambitious actions starting right now.

Net zero by 2050 is the goal. But countries also need to demonstrate how they will get there. Efforts to reach net-zero must be complemented with adaptation and resilience measures, and the mobilization of climate financing for developing countries.

So how can the world move toward net zero?

The good news is that the technology exists to reach net zero – and it is affordable.

A key element is powering economies with clean energy, replacing polluting coal - and gas and oil-fired power stations - with renewable energy sources, such as wind or solar farms. This would dramatically reduce carbon emissions. Plus, renewable energy is now not only cleaner, but often cheaper than fossil fuels.

A wholesale switch to electric transport, powered by renewable energy, would also play a huge role in lowering emissions, with the added bonus of slashing air pollution in the world’s major cities. Electric vehicles are rapidly becoming cheaper and more efficient, and many countries, including those committed to net zero, have proposed plans to phase out the sale of fossil-fuel powered cars.

Other harmful emissions come from agriculture (livestock produce significant levels of methane, a greenhouse gas). These could be reduced drastically if we eat less meat and more plant-based foods. Here again, the signs are promising, such as the rising popularity of "plant-based meats" now being sold in major international fast-food chains.

What will happen to remaining emissions?

Reducing emissions is extremely important. To get to net zero, we also need to find ways to remove carbon from the atmosphere. Here again, solutions are at hand. The most important have existed in nature for thousands of years.

 These "nature-based solutions" include forests, peatbogs, mangroves, soil and even underground seaweed forests , which are all highly efficient at absorbing carbon. This is why huge efforts are being made around the world to save forests, plant trees, and rehabilitate peat and mangrove areas, as well as to improve farming techniques.

Who is responsible for getting to net zero?

We are all responsible as individuals, in terms of changing our habits and living in a way which is more sustainable, and which does less harm to the planet, making the kind of lifestyle changes which are highlighted in the UN’s Act Now campaign.

The private sector also needs to get in on the act and it is doing so through the UN Global Compact , which helps businesses to align with the UN’s environmental and societal goals.

It’s clear, however, that the main driving force for change will be made at a national government level, such as through legislation and regulations to reduce emissions.

Many governments are now moving in the right direction. By early 2021, countries representing more than 65 per cent of global carbon dioxide emissions and more than 70 per cent of the world economy, will have made ambitious commitments to carbon neutrality.　

The European Union, Japan and the Republic of Korea, together with more than 110 other countries, have pledged carbon neutrality by 2050; China says it will do so before 2060.

Some climate facts:

The earth is now 1.1°C warmer than it was at the start of the industrial revolution. We are not on track to meet agreed targets in the 2015 Paris Agreement on climate change , which stipulated keeping global temperature increase well below 2 °C or at 1.5 °C above pre-industrial levels.

2010-2019 is the warmest decade on record. On the current path of carbon dioxide emissions, the global temperature is expected to increase by 3 to 5 degrees Celsius by the end of century.

To avoid the worst of warming (maximum 1.5°C rise), the world will need to decrease fossil fuel production by roughly 6 per cent per year between 2020 and 2030. Countries are instead planning and projecting an average annual increase of 2 per cent.

Climate action is not a budget buster or economy-wrecker: In fact, shifting to a green economy will add jobs. It could yield a direct economic gain of US$26 trillion through to 2030 compared with business-as-usual. And this is likely to be a conservative estimate.

Are these commitments any more than just political statements?

These commitments are important signals of good intentions to reach the goal, but must be backed by rapid and ambitious action. One important step is to provide detailed plans for action in nationally determined contributions or NDCs. These define targets and actions to reduce emissions within the next 5 to 10 years. They are critical to guide the right investments and attract enough finance.

So far, 186 parties to the Paris Agreement have developed NDCs. This year, they are expected to submit new or updated plans demonstrating higher ambition and action. Click here to see the NDC registry .

Is net zero realistic?

Yes! Especially if every country, city, financial institution and company adopts realistic plans for transitioning to net zero emissions by 2050.

The COVID-19 pandemic recovery could be an important and positive turning point. When economic stimulus packages kick in, there will be a genuine opportunity to promote renewable energy investments, smart buildings, green and public transport, and a whole range of other interventions that will help to slow climate change.

But not all countries are in the same position to affect change, are they?

That’s absolutely true. Major emitters, such as the G20 countries, which generate 80 per cent of carbon emissions, in particular, need to significantly increase their present levels of ambition and action.

Also, keep in mind that far greater efforts are needed to build resilience in vulnerable countries and for the most vulnerable people; they do the least to cause

climate change but bear the worst impacts. Resilience and adaptation action do not get the funding they need, however.

Even as they pursue net zero, developed countries must deliver on their commitment to provide $100 billion dollars a year for mitigation, adaptation and resilience in developing countries.

What is the UN doing promote climate action? 

It supports a broader process of global consensus on climate goals through the Paris Agreement and the 2030 Agenda for Sustainable Development .

It is a leading source of scientific findings and research on climate change.

Within developing countries, it assists governments with the practicalities of establishing and monitoring NDCs, and taking measures to adapt to climate change, such as by reducing disaster risks and establishing climate-smart agriculture.

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Science News

It’s possible to reach net-zero carbon emissions. here’s how.

Cutting carbon dioxide emissions to curb climate change is possible but not easy

Curbing climate change means getting more electricity from renewable sources, such as wind power.

Erik Isakson/ Tetra images/Getty Images

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By Alexandra Witze

January 27, 2023 at 7:00 am

Patricia Hidalgo-Gonzalez saw the future of energy on a broiling-hot day last September.

An email alert hit her inbox from the San Diego Gas & Electric Company. “Extreme heat straining the grid,” read the message, which was also pinged as a text to 27 million people. “Save energy to help avoid power interruptions.”

It worked. People cut their energy use. Demand plunged, blackouts were avoided and California successfully weathered a crisis exacerbated by climate change. “It was very exciting to see,” says Hidalgo-Gonzalez, an electrical engineer at the University of California, San Diego who studies renewable energy and the power grid.

This kind of collective societal response, in which we reshape how we interact with the systems that provide us energy, will be crucial as we figure out how to live on a changing planet.

Earth has warmed at least 1.1 degrees Celsius since the 19th century, when the burning of coal, oil and other fossil fuels began belching heat-trapping gases such as carbon dioxide into the atmosphere. Scientists agree that only drastic action to cut emissions can keep the planet from blasting past 1.5 degrees of warming — a threshold beyond which the consequences become even more catastrophic than the rising sea levels, extreme weather and other impacts the world is already experiencing.

The goal is to achieve what’s known as net-zero emissions, where any greenhouse gases still entering the atmosphere are balanced by those being removed — and to do it as soon as we can.

Scientists say it is possible to swiftly transform the ways we produce and consume energy. To show the way forward, researchers have set out paths toward a world where human activities generate little to no carbon dioxide and other greenhouse gases — a decarbonized economy.

The key to a decarbonized future lies in producing vast amounts of new electricity from sources that emit little to none of the gases, such as wind, solar and hydropower, and then transforming as much of our lives and our industries as possible to run off those sources. Clean electricity needs to power not only the planet’s current energy use but also the increased demands of a growing global population.

Once humankind has switched nearly entirely to clean electricity, we will also have to counter­balance the carbon dioxide we still emit — yes, we will still emit some — by pulling an equivalent amount of carbon dioxide out of the atmosphere and storing it somewhere permanently.

Achieving net-zero emissions won’t be easy. Getting to effective and meaningful action on climate change requires overcoming decades of inertia and denial about the scope and magnitude of the problem. Nations are falling well short of existing pledges to reduce emissions, and global warming remains on track to charge past 1.5 degrees perhaps even by the end of this decade.

Yet there is hope. The rate of growth in CO 2 emissions is slowing globally — down from 3 percent annual growth in the 2000s to half a percent annual growth in the last decade, according to the Global Carbon Project , which quantifies greenhouse gas emissions.

There are signs annual emissions could start shrinking. And over the last two years, the United States, by far the biggest cumulative contributor to global warming, has passed several pieces of federal legislation that include financial incentives to accelerate the transition to clean energy. “We’ve never seen anything at this scale,” says Erin Mayfield, an energy researcher at Dartmouth College.

Though the energy transition will require many new technologies, such as innovative ways to permanently remove carbon from the atmosphere, many of the solutions, such as wind and solar power, are in hand — “stuff we already have,” Mayfield says.

How to hit net-zero carbon emissions by 2050

In a 2021 report, the International Energy Agency described the steps necessary to ensure that by 2050 the amount of carbon dioxide emitted into the atmosphere globally balances the amount being taken out. This chart shows how carbon dioxide emissions would have to drop across sectors to bring planetwide emissions from roughly 34 billion metric tons annually to net-zero.  

The current state of carbon dioxide emissions

Of all the emissions that need to be slashed, the most important is carbon dioxide, which comes from many sources such as cars and trucks and coal-burning power plants. The gas accounted for 79 percent of U.S. greenhouse gas emissions in 2020. The next most significant greenhouse gas, at 11 percent of emissions in the United States, is methane, which comes from oil and gas operations as well as livestock, landfills and other land uses.

The amount of methane may seem small, but it is mighty — over the short term, methane is more than 80 times as efficient at trapping heat as carbon dioxide is, and methane’s atmospheric levels have nearly tripled in the last two centuries. Other greenhouse gases include nitrous oxides, which come from sources such as applying fertilizer to crops or burning fuels and account for 7 percent of U.S. emissions, and human-made fluorinated gases such as hydrofluorocarbons that account for 3 percent.

Globally, emissions are dominated by large nations that produce lots of energy. The United States alone emits around 5 billion metric tons of carbon dioxide each year. It is responsible for most of the greenhouse gas emissions throughout history and ceded the spot for top annual emitter to China only in the mid-2000s. India ranks third.

Because of the United States’ role in producing most of the carbon pollution to date, many researchers and advocates argue that it has the moral responsibility to take the global lead on cutting emissions. And the United States has the most ambitious goals of the major emitters, at least on paper. President Joe Biden has said the country is aiming to reach net-zero emissions by 2050. Leaders in China and India have set net-zero goals of 2060 and 2070, respectively.

Under the auspices of a 2015 international climate change treaty known as the Paris agreement, 193 nations plus the European Union have pledged to reduce their emissions. The agreement aims to keep global warming well below 2 degrees, and ideally to 1.5 degrees, above preindustrial levels. But it is insufficient. Even if all countries cut their emissions as much as they have promised under the Paris agreement, the world would likely blow past 2 degrees of warming before the end of this century. 

Every nation continues to find its own path forward. “At the end of the day, all the solutions are going to be country-specific,” says Sha Yu, an earth scientist at the Pacific Northwest National Laboratory and University of Maryland’s Joint Global Change Research Institute in College Park, Md. “There’s not a universal fix.”

But there are some common themes for how to accomplish this energy transition — ways to focus our efforts on the things that will matter most. These are efforts that go beyond individual consumer choices such as whether to fly less or eat less meat. They instead penetrate every aspect of how society produces and consumes energy.

Such massive changes will need to overcome a lot of resistance, including from companies that make money off old forms of energy as well as politicians and lobbyists. But if society can make these changes, it will rank as one of humanity’s greatest accomplishments. We will have tackled a problem of our own making and conquered it.

Here’s a look at what we’ll need to do.

Make as much clean electricity as possible

To meet the need for energy without putting carbon dioxide into the atmosphere, countries would need to dramatically scale up the amount of clean energy they produce. Fortunately, most of that energy would be generated by technologies we already have — renewable sources of energy including wind and solar power.

“Renewables, far and wide, are the key pillar in any net-zero scenario,” says Mayfield, who worked on an influential 2021 report from Princeton University’s Net-Zero America project , which focused on the U.S. economy.

The Princeton report envisions wind and solar power production roughly quadrupling by 2030 to get the United States to net-zero emissions by 2050. That would mean building many new solar and wind farms, so many that in the most ambitious scenario, wind turbines would cover an area the size of Arkansas, Iowa, Kansas, Missouri, Nebraska and Oklahoma combined.

How much solar and wind power would we need?

Achieving net-zero would require a dramatic increase in solar and wind power in the United States. These maps show the footprint of existing solar and wind infrastructure in the contiguous United States (as of 2020) and a possible footprint for a midrange scenario for 2050. Gray shows population density of 100 people per square kilometer or greater.

Such a scale-up is only possible because prices to produce renewable energy have plunged. The cost of wind power has dropped nearly 70 percent, and solar power nearly 90 percent, over the last decade in the United States. “That was a game changer that I don’t know if some people were expecting,” Hidalgo-Gonzalez says.

Globally the price drop in renewables has allowed growth to surge; China, for instance, installed a record 55 gigawatts of solar power capacity in 2021, for a total of 306 gigawatts or nearly 13 percent of the nation’s installed capacity to generate electricity. China is almost certain to have had another record year for solar power installations in 2022.

Challenges include figuring out ways to store and transmit all that extra electricity, and finding locations to build wind and solar power installations that are acceptable to local communities. Other types of low-carbon power, such as hydropower and nuclear power, which comes with its own public resistance, will also likely play a role going forward.

More renewable electricity globally

Renewable energy sources, such as solar, wind and hydropower, account for a larger share of global electricity generation today than they did in 2015. The International Energy Agency expects that trend to continue, projecting that renewables will top 38 percent in 2027.

Get efficient and go electric

The drive toward net-zero emissions also requires boosting energy efficiency across industries and electrifying as many aspects of modern life as possible, such as transportation and home heating.

Some industries are already shifting to more efficient methods of production, such as steelmaking in China that incorporates hydrogen-based furnaces that are much cleaner than coal-fired ones, Yu says. In India, simply closing down the most inefficient coal-burning power plants provides the most bang for the buck, says Shayak Sengupta, an energy and policy expert at the Observer Research Foundation America think tank in Washington, D.C. “The list has been made up,” he says, of the plants that should close first, “and that’s been happening.”

To achieve net-zero, the United States would need to increase its share of electric heat pumps, which heat houses much more cleanly than gas- or oil-fired appliances, from around 10 percent in 2020 to as much as 80 percent by 2050, according to the Princeton report. Federal subsidies for these sorts of appliances are rolling out in 2023 as part of the new Inflation Reduction Act , legislation that contains a number of climate-related provisions.

Shifting cars and other vehicles away from burning gasoline to running off of electricity would also lead to significant emissions cuts. In a major 2021 report , the National Academies of Sciences, Engineering and Medicine said that one of the most important moves in decarbonizing the U.S. economy would be having electric vehicles account for half of all new vehicle sales by 2030. That’s not impossible; electric car sales accounted for nearly 6 percent of new sales in the United States in 2022, which is still a low number but nearly double the previous year .

Make clean fuels

Some industries such as manufacturing and transportation can’t be fully electrified using current technologies — battery powered airplanes, for instance, will probably never be feasible for long-duration flights. Technologies that still require liquid fuels will need to switch from gas, oil and other fossil fuels to low-carbon or zero-carbon fuels.

One major player will be fuels extracted from plants and other biomass, which take up carbon dioxide as they grow and emit it when they die, making them essentially carbon neutral over their lifetime. To create biofuels, farmers grow crops, and others process the harvest in conversion facilities into fuels such as hydrogen. Hydrogen, in turn, can be substituted for more carbon-intensive substances in various industrial processes such as making plastics and fertilizers — and maybe even as fuel for airplanes someday.

In one of the Princeton team’s scenarios, the U.S. Midwest and Southeast would become peppered with biomass conversion plants by 2050, so that fuels can be processed close to where crops are grown. Many of the biomass feedstocks could potentially grow alongside food crops or replace other, nonfood crops.

Solar and wind power trends in the United States

The amount of electricity generated from wind and solar power in the United States has surged in the last decade. The boost was made possible in large part by drops in the costs of producing that energy.

Cut methane and other non-CO 2 emissions

Greenhouse gas emissions other than carbon dioxide will also need to be slashed. In the United States, the majority of methane emissions come from livestock, landfills and other agricultural sources, as well as scattered sources such as forest fires and wetlands. But about one-third of U.S. methane emissions come from oil, gas and coal operations. These may be some of the first places that regulators can target for cleanup, especially “super emitters” that can be pinpointed using satellites and other types of remote sensing .

In 2021, the United States and the European Union unveiled what became a global methane pledge endorsed by 150 countries to reduce emissions. There is, however, no enforcement of it yet. And China, the world’s largest methane emitter, has not signed on.

Nitrous oxides could be reduced by improving soil management techniques, and fluorinated gases by finding alternatives and improving production and recycling efforts.

Sop up as much CO 2 as possible

Once emissions have been cut as much as possible, reaching net-zero will mean removing and storing an equivalent amount of carbon to what society still emits.

One solution already in use is to capture carbon dioxide produced at power plants and other industrial facilities and store it permanently somewhere, such as deep underground. Globally there are around 35 such operations, which collectively draw down around 45 million tons of carbon dioxide annually. About 200 new plants are on the drawing board to be operating by the end of this decade, according to the International Energy Agency.

The Princeton report envisions carbon capture being added to almost every kind of U.S. industrial plant, from cement production to biomass conversion. Much of the carbon dioxide would be liquefied and piped along more than 100,000 kilometers of new pipelines to deep geologic storage, primarily along the Texas Gulf Coast, where underground reservoirs can be used to trap it permanently. This would be a massive infrastructure effort. Building this pipeline network could cost up to $230 billion, including $13 billion for early buy-in from local communities and permitting alone.

Another way to sop up carbon is to get forests and soils to take up more. That could be accomplished by converting crops that are relatively carbon-intensive, such as corn to be used in ethanol, to energy-rich grasses that can be used for more efficient biofuels, or by turning some cropland or pastures back into forest. It’s even possible to sprinkle crushed rock onto croplands, which accelerates natural weathering processes that suck carbon dioxide out of the atmosphere.

Another way to increase the amount of carbon stored in the land is to reduce the amount of the Amazon rainforest that is cut down each year. “For a few countries like Brazil, preventing deforestation will be the first thing you can do,” Yu says.

When it comes to climate change, there’s no time to waste

The Princeton team estimates that the United States would need to invest at least an additional $2.5 trillion over the next 10 years for the country to have a shot at achieving net-zero emissions by 2050. Congress has begun ramping up funding with two large pieces of federal legislation it passed in 2021 and 2022. Those steer more than $1 trillion toward modernizing major parts of the nation’s economy over a decade — including investing in the energy transition to help fight climate change.

Between now and 2030, solar and wind power, plus increasing energy efficiency, can deliver about half of the emissions reductions needed for this decade, the International Energy Agency estimates. After that, the primary drivers would need to be increasing electrification, carbon capture and storage, and clean fuels such as hydrogen.

The trick is to do all of this without making people’s lives worse. Developing nations need to be able to supply energy for their economies to develop. Communities whose jobs relied on fossil fuels need to have new economic opportunities.

Julia Haggerty, a geographer at Montana State University in Bozeman who studies communities that are dependent on natural resources, says that those who have money and other resources to support the transition will weather the change better than those who are under-resourced now. “At the landscape of states and regions, it just remains incredibly uneven,” she says.

The ongoing energy transition also faces unanticipated shocks such as Russia’s invasion of Ukraine, which sent energy prices soaring in Europe, and the COVID-19 pandemic, which initially slashed global emissions but later saw them rebound.

But the technologies exist for us to wean our lives off fossil fuels. And we have the inventiveness to develop more as needed. Transforming how we produce and use energy, as rapidly as possible, is a tremendous challenge — but one that we can meet head-on. For Mayfield, getting to net-zero by 2050 is a realistic goal for the United States. “I think it’s possible,” she says. “But it doesn’t mean there’s not a lot more work to be done.”

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What Does "Net-Zero Emissions" Mean? 8 Common Questions, Answered

• climate science
• carbon removal
• Paris Agreement
• climate policy
• greenhouse gases

Editor's Note: This article was updated in March 2023 to include WRI’s latest research and information about new national net-zero targets.

The latest  climate science  is clear: Limiting global warming to 1.5 degrees C (2.7 degrees F) is still possible. But to avoid the worst climate impacts, global greenhouse gas (GHG) emissions will need to  drop by nearly half by 2030  and ultimately reach net zero.

Recognizing this urgency, a rapidly growing number of national governments, local governments and business leaders are making commitments to reach net-zero emissions within their jurisdictions or businesses. To date,  over 90 countries  have communicated such “net-zero targets,” including the world’s largest emitters (China, the United States and India). On top of that, hundreds more regions, cities and companies have set targets of their own.

But what does a net-zero target mean, what’s the science behind net zero and which countries have already made such commitments? Here are answers to eight common questions:

1. What Does Net-Zero Emissions Mean?

Net-zero emissions, or “net zero,” will be achieved when all emissions released by human activities are counterbalanced by removing carbon from the atmosphere in a process known as  carbon removal .

Achieving net zero will require a two-part approach: First and foremost, human-caused emissions (such as those from fossil-fueled vehicles and factories) should be reduced as close to zero as possible. Any remaining emissions should then be balanced with an equivalent amount of carbon removal, which can happen through natural approaches like restoring forests or through technologies like  direct air capture and storage  (DACS), which scrubs carbon directly from the atmosphere.

2. When Does the World Need to Reach Net-Zero Emissions?

Under the Paris Agreement, countries agreed to limit warming to well below 2 degrees C (3.6 degrees F), ideally to  1.5 degrees C  (2.7 degrees F). Global climate impacts that are already unfolding under the current  1.1 degrees C  (1.98 degrees F) of warming — from melting ice to devastating heat waves and more intense storms — show the urgency of minimizing temperature increase.

The  latest science  suggests that limiting warming to 1.5 degrees C depends on CO2 emissions reaching net zero between 2050 and 2060.  Reaching net zero earlier in that range (closer to 2050) avoids a risk of temporarily "overshooting," or exceeding 1.5 degrees C. Reaching net zero later (nearer to 2060) almost guarantees surpassing 1.5 degrees C for some time before global temperature can be reduced back to safer limits through carbon removal.

Critically, the sooner  emissions peak , and the lower they are at that point, the more realistic achieving net zero becomes. This would also create less reliance on carbon removal in the second half of the century.

This does not suggest that all countries need to reach net-zero emissions at the same time. However, the chances of limiting warming to 1.5 degrees C depend significantly on how soon the highest emitters reach net zero. Equity-related considerations — including responsibility for past emissions, equality in per-capita emissions and capacity to act — also suggest earlier dates for wealthier, higher-emitting countries.

Importantly, the time frame for reaching net-zero emissions is different for CO2 alone versus for CO2 plus other greenhouse gases like methane, nitrous oxide and fluorinated gases. For non-CO2 emissions, the net zero date is later, in part because models assume that some of these emissions — such as methane from agricultural sources — are more difficult to phase out. However, these potent but short-lived gases will  drive temperatures higher  in the near term, potentially pushing temperature change past the 1.5 degrees C threshold much earlier.

Because of this, it's important for countries to specify whether their net-zero targets cover CO2 only or all GHGs. A comprehensive net-zero emissions target would include all GHGs, ensuring that non-CO2 gases are also reduced with urgency.

3. Is the World on Track to Reach Net-Zero Emissions on Time?

No — despite the enormous benefits of climate action to date, progress is happening far too slowly for the world to hold temperature rise to 1.5 degrees C (2.7 degrees F). The UN finds  that climate policies currently in place point to a 2.8 degrees C temperature rise by the end of the century.

4. What Needs to Happen to Achieve Net-Zero Emissions?

To achieve net-zero emissions, rapid transformation will be required across all global systems — from how we power our economies, to how we transport people and goods and feed a growing population.

For example, in pathways to 1.5 degrees C, zero-carbon sources will need to supply  98%-100% of electricity by 2050 . Energy efficiency and fuel-switching measures are critical for reducing emissions from transportation. Improving the efficiency of food production, changing dietary choices,  restoring degraded lands  and reducing food loss and waste  also have significant potential  to reduce emissions.

Additionally, action must be taken to reverse course in cases where change is at a standstill or headed in the wrong direction entirely. For instance , efforts to phase out unabated coal remain well off-track and must decline six times faster by 2030. The world also needs to halt deforestation and increase tree cover gain two times faster by 2030.

It is critical that the structural and economic transition toward net zero is approached in a just manner , especially for workers tied to high-carbon industries. Indeed, the costs and benefits of transitioning to a net-zero emissions economy must be distributed equitably.

The good news is that most of the technologies needed to unlock net zero are already available and increasingly cost-competitive with high-carbon alternatives. Solar and wind now provide the  cheapest power  available for most of the world. Markets are waking up to these opportunities and to the risks of a high-carbon economy, and they are shifting accordingly.

Investments in carbon removal techniques are also necessary. The different pathways assessed by the IPCC to achieve 1.5 degrees C  all rely on carbon removal to some extent . Removing CO2 from the atmosphere will compensate for emissions from sectors in which reaching net-zero emissions is more difficult, such as aviation.

5. How Many Countries Have Set Net-Zero Targets?

Global momentum for setting net-zero targets is growing quickly, with key economies like China, the United States, India and the European Union articulating such commitments. Bhutan was the first country to set a net-zero target in 2015. Now over 90 countries, representing nearly 80% of global emissions, are covered by a net-zero target.

Climate Watch’s  Net-Zero Tracker  shows how these targets were set, such as through nationally determined contributions (NDCs), long-term low GHG emissions development strategies (long-term strategies), domestic laws, policies, or high-level political pledges from heads of state or other cabinet members. The tracker also includes information on the scope of national net-zero targets, providing details about the GHGs and sectors covered by each, the extent to which the target relies on international offsets and more.

6. Does the Paris Agreement Commit Countries to Achieving Net-Zero Emissions?

In short, yes. Specifically, the Paris Agreement sets a  long-term goal  of achieving "a balance between anthropogenic emissions by sources and removals by sinks of greenhouse gases in the second half of this century, on the basis of equity, and in the context of sustainable development and efforts to eradicate poverty." This concept of balancing emissions and removals is akin to reaching net-zero emissions.

The  Glasgow Climate Pact , signed at COP26 and marking the five-year anniversary of the Paris Agreement, also emphasized the importance of setting ambitious net zero goals. The pact urges countries to move “towards just transitions to net zero emissions by or around midcentury, taking into account different national circumstances.”  To this end, it encourages parties “that have not yet done so to communicate…long-term low greenhouse gas emission development strategies” that set the country on a pathway toward net zero. The shift from “in the second half of this century” to “by or around mid-century” reflects a notable increase in perceived urgency.

7. Why and How Should Countries Align Their Near-term Emissions Reduction Targets with Longer-term Net-Zero Goals?

Countries typically set net-zero targets for around 2050 — nearly three decades from now. However, to ensure that the world gets on the right track toward reaching net zero, those long-term objectives must guide and inform near-term action today. This will help avoid  locking in  carbon-intensive, non-resilient infrastructure and technologies. Countries can also cut near- and long-term costs by investing in green infrastructure that will not need to be phased out later, designing consistent policies and sending strong signals to the private sector to invest in climate action.

Under the Paris Agreement, countries agreed to submit climate plans every five years, known as  nationally determined contributions (NDCs ). NDCs, which currently target 2030, are an important tool to align near- and long-term emissions reduction goals. When informed by a country’s long-term vision, these documents can help governments implement the policies necessary today to realize an ambitious mid-century objective.

Many countries with net-zero targets are beginning to incorporate them directly into their NDCs, particularly now that the Glasgow Climate Pact “notes the importance of aligning nationally determined contributions with long-term low greenhouse gas emission development strategies.”

8. Are Net-Zero Targets a Form of Greenwashing?

Not necessarily, but they can be if used as an excuse to not take bold climate action in the near term.

Although net-zero targets continue to gain traction with governments and companies, skeptical voices have emerged, from  academic journals  to  Greta Thunberg’s speech  in Davos. Critiques of net-zero targets include:

The “net” aspect of net-zero targets could dampen efforts to rapidly cut emissions.

Critics are concerned that this could foster an overreliance on carbon removal, allowing decision-makers to use net-zero targets to avoid emission reductions in the near term. Decision-makers can address this concern by setting ambitious gross reduction targets (targets that do not rely on removals) alongside their longer-term net reduction targets.

Some countries’ net-zero targets rely on purchasing emissions reductions, delaying reductions within their own boundaries.

Some countries are setting net-zero targets that rely on carbon offsetting, which involves investing in or paying for emissions reductions from other countries to use toward their own targets. There’s concern that government leaders might use this strategy to avoid reducing their own emissions in the long term. Decision-makers can address this concern by setting deep emission reduction targets that explicitly avoid or limit using offsets to achieve their goals.

WRI’s experts are closely following the UN climate talks. Watch our  Resource Hub  for new articles, research, webinars and more.

The time horizon for net-zero targets — typically 2050 — feels distant.

Today’s infrastructure can last for decades and have a major impact on mid-century targets. Decision-makers must take this into account by establishing near- and mid-term milestones for their path to net-zero emissions, including by setting ambitious 2030 emission reduction targets as part of their NDCs. NDCs are subject to transparency and accountability mechanisms under the Paris Agreement that can foster implementation in the near term, which is critical for a long-term net-zero goal to be credible.

In short, net-zero commitments must be robust  to be effective and advance climate action. Countries must take concrete steps to ensure this if they are to effectively address the challenge at hand.

Relevant Work

Designing and communicating net-zero targets, your country set a net-zero target: what's next, tracking climate action: how the world can still limit warming to 1.5 degrees c, how you can help.

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Why is net zero so important in the fight against climate change?

What is net zero and why is it needed?

The term ‘net zero’ refers to the target of reducing the greenhouse gas emissions that cause global warming to zero by balancing the amount released into the atmosphere with the amount removed and stored by carbon sinks. This is also described as ‘carbon neutrality’ or ‘climate neutrality’.

The Intergovernmental Panel on Climate Change (IPCC) stated in 2018 that the world needs to reach net zero by around 2050 if it is to meet the Paris Agreement target of limiting global warming to 1.5°C. The 2050 deadline was subsequently included in the Glasgow Climate Pact agreed at COP26 in 2021. Parties signed up to the Pact recognise that “limiting global warming to 1.5°C requires rapid, deep and sustained reductions in global greenhouse gas emissions, including reducing global carbon dioxide emissions … to net zero around mid-century”.

Governments are increasingly accepting that net zero targets need to be included in their Nationally Determined Contributions (NDCs), and a growing number are legislating for net zero (see below). However, the United Nations Environment Programme’s  Emissions Gap Report  of October 2022 found that, “In the best-case scenario, full implementation of conditional NDCs, plus additional net zero commitments, point to a 1.8°C rise [but] this scenario is currently not credible.”

Achieving net zero through emissions abatement, negative emissions and offsetting

Getting to net zero requires significant abatement of greenhouse gas emissions across all sectors of the economy. For example, in the energy sector – the source of around three-quarters of emissions – switching from fossil fuels to renewables including wind and solar power to generate electricity is significantly reducing carbon dioxide emissions in many countries. To make deeper cuts in emissions, large-scale investment and innovation are needed, firstly to provide technologically-viable and economically-competitive alternatives to fossil-fuel-intensive technologies in sectors like heating and transport, and secondly to reduce emissions of greenhouse gases other than carbon dioxide (such as methane) from sectors like agriculture. 

Abating emissions from some sectors – such as cement, aviation and shipping – is currently difficult and expensive and it is unlikely they will be reduced to zero in the timescale needed to meet the Paris Agreement temperature targets. Therefore, there will be ‘residual’ emissions and the equivalent amount of these will need to be removed from the atmosphere as ‘negative emissions’. This can be done by offsetting from sectors such as land use and power, which have the potential to deploy greenhouse gas removal technologies, in order to achieve net zero across an economy. However, the technologies in question, which include Direct Air Capture (DAC) and Bioenergy with Carbon Capture and Storage (BECCS), are not yet proven at scale, can be expensive and energy-intensive, and have their own unwanted negative impacts.

Greenhouse gases can also be removed using nature-based solutions such as  planting trees , and through land management changes to increase the amount of carbon sequestered into soil.

Governments may use international offsets to meet their own individual net zero targets. Offsets are used especially if it is difficult for the country to reduce some of its own territorial emissions: for example if,  like Norway , it has a large oil and gas industry. Buying offsets allows a country to invest in an emissions reduction project outside its borders but is sometimes criticised for ‘moving the problem elsewhere’ and in some countries there is poor governance of offsets. 

Because of the limits to negative emissions technologies and the criticisms of offsetting, climate scientists stress the need to focus on abating domestic emissions as the primary way to bring emissions to net zero and thus avoid dangerous climate change.

Who is setting net zero laws and targets?

National governments.

The Net Zero Tracker’s 2022 Stocktake Report finds that 128 countries and territories have some sort of net zero target. In 2019 the United Kingdom became the first major economy to legislate for net zero (by 2050), following  guidance  from the UK’s independent advisory body, the Climate Change Committee, which stressed that a net zero target was essential for the country to meet its commitments to the Paris Agreement goals. 

Of the world’s biggest emitters, China in 2020 committed to achieving ‘climate neutrality’ by 2060 – a crucial pledge for enabling the world as a whole to limit temperature rise to 1.5 or 2°C. The European Union set out its bloc-wide  net zero target for 2050  in its  European Green Deal  published  in December 2019. The United States has also committed to net zero emissions by 2050 at the latest.

While the number of net zero laws is increasing, less positively the Net Zero Tracker highlights that more than 75% of national and sub-national governments are not transparent on whether they intend to use external offsetting to meet their targets.

Businesses and finance

Businesses and the financial sector are also making net zero commitments, and at an increasing pace. It is hoped that these actions – along with those from cities and regions – will both directly contribute to meeting the Paris goals and influence national governments to commit more to reducing emissions.

Under the umbrella of the UN’s Race to Zero campaign, more than 450 institutions including banks, insurers and investors, responsible for over US$130 trillion of private finance assets, have committed to net zero targets through the Glasgow Financial Alliance for Net Zero (GFANZ). There are various initiatives to support the private sector in reducing its emissions in line with the Paris Agreement, for instance providing guidance on setting credible pledges, and criteria against which to monitor progress, highlight gaps and hold organisations to account. These include UN guidance for ‘non-state entities’ (including businesses and cities), the Science Based Targets initiative (SBTi), the Transition Pathway Initiative (TPI), and Climate Action 100+ .

Cities and regions

Individual cities and regions are also setting net zero targets. Cities are taking independent action to reduce emissions (e.g. London has expanded its Ultra Low Emission Zone to become the largest zone of its kind in Europe), and they are also acting in coalitions. For example, more than 1,000 cities and local governments have joined the Cities Race to Zero to “raise climate ambition” and contribute to reaching the 2050 net zero target. Cities are home to more than half of the human population and in democracies their inhabitants can influence national policy with their voting choices; they make an outsized contribution to emissions; and they are likely to suffer acute climate impacts – so their role in climate action is very important.

This Explainer was written by Georgina Kyriacou with Josh Burke.

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• A-Z Publications

Annual Review of Environment and Resources

Volume 47, 2022, review article, open access, net zero: science, origins, and implications.

• Myles R. Allen 1,4 , Pierre Friedlingstein 2,3 , Cécile A.J. Girardin 1 , Stuart Jenkins 4 , Yadvinder Malhi 1,5 , Eli Mitchell-Larson 1 , Glen P. Peters 6 , and Lavanya Rajamani 7
• View Affiliations Hide Affiliations Affiliations: 1 Environmental Change Institute, School of Geography and the Environment, University of Oxford, Oxford, United Kingdom; email: [email protected] 2 College of Engineering, Mathematics and Physical Sciences, University of Exeter, Exeter, United Kingdom 3 Laboratoire de Météorologie Dynamique, Institut Pierre-Simon Laplace, CNRS-ENS-UPMC-X, Paris, France 4 Department of Physics, University of Oxford, Oxford, United Kingdom 5 Leverhulme Centre for Nature Recovery, University of Oxford, Oxford, United Kingdom 6 CICERO Center for International Climate Research (CICERO), Oslo, Norway 7 Faculty of Law, University of Oxford, Oxford, United Kingdom
• Vol. 47:849-887 (Volume publication date October 2022) https://doi.org/10.1146/annurev-environ-112320-105050
• First published as a Review in Advance on August 26, 2022
• Copyright © 2022 by Annual Reviews. This work is licensed under a Creative Commons Attribution 4.0 International License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. See credit lines of images or other third-party material in this article for license information

This review explains the science behind the drive for global net zero emissions and why this is needed to halt the ongoing rise in global temperatures. We document how the concept of net zero carbon dioxide (CO 2 ) emissions emerged from an earlier focus on stabilization of atmospheric greenhouse gas concentrations. Using simple conceptual models of the coupled climate–carbon cycle system, we explain why approximately net zero CO 2 emissions and declining net energy imbalance due to other climate drivers are required to halt global warming on multidecadal timescales, introducing important concepts, including the rate of adjustment to constant forcing and the rate of adjustment to zero emissions. The concept of net zero was taken up through the 5th Assessment Report of the Intergovernmental Panel on Climate Change and the United Nations Framework Convention on Climate Change (UNFCCC) Structured Expert Dialogue, culminating in Article 4of the 2015 Paris Agreement. Increasing numbers of net zero targets have since been adopted by countries, cities, corporations, and investors. The degree to which any entity can claim to have achieved net zero while continuing to rely on distinct removals to compensate for ongoing emissions is at the heart of current debates over carbon markets and offsetting both inside and outside the UNFCCC. We argue that what matters here is not the precise makeup of a basket of emissions and removals at any given point in time, but the sustainability of a net zero strategy as a whole and its implications for global temperature over multidecadal timescales. Durable, climate-neutral net zero strategies require like-for-like balancing of anthropogenic greenhouse gas sources and sinks in terms of both origin (biogenic versus geological) and gas lifetime.

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• 22 April 2024
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Will AI accelerate or delay the race to net-zero emissions?

• Amy Luers   ORCID: http://orcid.org/0009-0002-8028-6039 0 ,
• Jonathan Koomey   ORCID: http://orcid.org/0000-0002-2983-344X 1 ,
• Eric Masanet   ORCID: http://orcid.org/0000-0003-3507-8986 2 ,
• Owen Gaffney   ORCID: http://orcid.org/0000-0001-6244-991X 3 ,
• Felix Creutzig   ORCID: http://orcid.org/0000-0002-5710-3348 4 ,
• Juan Lavista Ferres 5 &
• Eric Horvitz   ORCID: http://orcid.org/0000-0002-8823-0614 6

Amy Luers is senior global director of Sustainability Science and Innovation, Microsoft, Redmond, Washington, USA.

You can also search for this author in PubMed   Google Scholar

Jonathan Koomey is an independent researcher at Koomey Analytics, Burlingame, California, USA.

Eric Masanet is a professor of sustainability science for emerging technologies at the University of California, Santa Barbara, USA, and a faculty scientist in the Energy Analysis and Environmental Impacts Division at Lawrence Berkeley National Laboratory, Berkeley, California, USA.

Owen Gaffney is chief impact officer at the Exponential Roadmap Initiative, Stockholm, and Nobel Prize Outreach, Stockholm, Sweden.

Felix Creutzig is principal investigator at the Mercator Research Institute on Global Commons and Climate Change and professor of sustainability economics at the Technical University Berlin, Germany.

Juan Lavista Ferres is chief data scientist at Microsoft, Redmond, Washington, USA.

Eric Horvitz is chief scientific officer at Microsoft, Redmond, Washington, USA.

Driverless taxis run by artificial intelligence use less fuel than conventional ones, but the wider climate impacts are unclear. Credit: Allen J. Schaben/Los Angeles Times/Getty

You have full access to this article via your institution.

Artificial intelligence (AI) is already transforming the global economy . Companies are investing hundreds of billions of dollars each year in these technologies. In almost every sector, AI is being used to drive operational efficiencies, manage complexity, provide personalized services and speed up innovation.

As AI’s influence on society grows, questions arise about its impact on greenhouse-gas emissions: will its myriad applications help to reduce the world’s carbon footprint or hinder climate progress? The answer will depend on how AI models are developed and operated, and what changes result from their use. And scientists simply don’t know how all that will pan out — a worrying situation when there is so much at stake.

Most discussions so far about AI’s environmental consequences have focused on the direct impacts of these computationally intensive technologies — how much energy, water or other resources they consume and the amount of greenhouse gases they generate. But the global repercussions of AI applications for society will be much broader, from transforming health care and education to increasing the efficiency of mining, transportation and agriculture.

Such AI-driven changes can lead to indirect effects on emissions, which might be positive or negative. These indirect effects also need to be taken into account, and could vastly exceed those from direct impacts 1 , 2 . Assessments of all types of AI impact are urgently needed. Here’s what we know and what we don’t.

Uncertainty ahead

The direct impacts of AI on climate so far are relatively small. AI operations for large models require millions of specialized processors in dedicated data centres with powerful cooling systems. AI processors installed in 2023 consume 7–11 terawatt hours (TWh) of electricity annually, which is about 0.04% of global electricity use 3 . That is less than for cryptocurrency mining (100–150 TWh) and conventional data centres plus data-transmission networks (500–700 TWh), which together accounted for 2.4–3.3% of global electricity demand in 2022, according to the International Energy Agency (IEA). Thus, in terms of total global greenhouse-gas emissions, we calculate that AI today is responsible for about 0.01%, on the basis of IEA assessments showing that data centres and transmission networks together account for about 0.6% (see go.nature.com/3q7e6pv ).

AI use is expanding rapidly. Over the past decade, the compute capacity used to train advanced large language models has increased tenfold each year . Demand for AI services is expected to rise by 30–40% annually over the next 5–10 years. And more powerful AI models will require more energy. One estimate suggests that, by 2027, global AI-related energy consumption could be 10 times greater than it was in 2023 3 , or about as much as is consumed annually by people watching television in US homes. Although there could be challenges for local electricity grids in regions where many data centres are based, from a global perspective, AI should not lead directly to large, near-term increases in greenhouse-gas emissions.

Improvements in energy efficiency could offset some of the projected increase in power demand, as they did when data centres expanded in the 2010s 4 . More-efficient AI algorithms, smaller models and innovations in hardware and cooling systems should help 5 , 6 . For example, small language models, such as Microsoft’s Phi-2 and Google’s Gemini Nano, can run on mobile phones and deliver capabilities previously seen only with the largest models. AI companies are increasingly investing in renewable power and setting up operations in countries or regions with abundant clean-energy supplies, such as Iceland.

Indirect effects are less clear, however. Some AI applications are designed to tackle climate change, for example to reduce emissions from the energy and transport sectors, from buildings and industry operations and from land use. Optimizing supply chains will make manufacturing more efficient and support the integration of renewable energy into electricity grids . Speeding up the development of new materials for batteries and renewable energy 7 , 8 will be a boon.

There could also be some negative indirect impacts. Embedding AI into existing applications, from health care to entertainment, might drive more electricity use. Oil and gas exploration and extraction could become cheaper, potentially driving up production. And without proper governance, the widespread use of AI could affect political and economic stability, with ramifications for poverty, food security and social inequalities — all of which could have knock-on effects for emissions 9 .

And that’s just existing AI systems. How will future AI technologies develop? How will their expansion affect the global economy? And how will this affect decarbonization? Researchers simply don’t know; it’s too early to tell. It is tempting to simply extrapolate past AI electricity-use trends into the future, but overlooking social, economic and technological factors often results in large forecasting errors 4 , 5 , 10 . Similarly, an overly simplistic view of the impacts of indirect emissions risks underestimating AI’s potential for accelerating important climate-solution breakthroughs, such as the development of less expensive and more powerful batteries in months rather than decades 11 .

AI-driven emissions scenarios

Recognizing these huge uncertainties, here we call on researchers to develop a set of policy-relevant scenarios to quantify the effects that AI expansion could have on the climate under a range of assumptions. Routinely used by financial institutions to understand risks and opportunities and plan investments, scenarios combine quantitative models with expert consultations. Rather than making predictions, they explore many possible futures based on influential factors.

A data centre near Reykjavik uses renewable energy for cooling. Credit: Sigtryggur Ari/Reuters

Specifically, we recommend that a suite of scenarios be built to better understand how AI expansion might affect emissions, both directly and indirectly. These scenarios should range from a ‘reference’ case without widespread adoption of powerful AI technologies, to an ‘aspirational’ case in which all the United Nations Sustainable Development Goals are achieved; scenarios should also include ones with undesirable outcomes.

Five elements are essential for AI-driven emissions scenarios to be credible and useful.

Link to existing climate scenarios. The climate community already uses integrated assessment models (IAMs) to assess future greenhouse-gas emissions quantitatively on the basis of qualitative narratives about potential socio-economic, demographic, policy, technology and governance outcomes. Five standard scenarios, or Shared Socioeconomic Pathways (SSPs), are widely used. These range from a future in which the world is deeply divided and remains hooked on fossil fuels to a more optimistic scenario of global cooperation, decoupling of economic growth from emissions and serious investment in clean energy.

AI should be integrated into these pathways, along with the global shocks and technological breakthroughs that might accompany it. This would require major work, including incorporating expertise from the AI community, rethinking each of the pathway narratives and exploring whether new ones need to be added. Could AI take the world to a more radically green future, or a more dystopian one? What factors define those outcomes? How plausible are they? Scenarios can help to narrow down answers.

Turning these narratives into quantitative scenarios will require developing new analytical models, collecting new types of data and establishing an institutional structure to enable rapid updates to keep up with the fast pace of societal transformations that AI is driving, as we outline here.

Develop quantitative analytical frameworks. Developing IAMs for exploring the influence of AI will require improved data and analytical frameworks for both direct and indirect impacts. The biggest challenge will be quantifying the range of indirect effects resulting from AI-driven societal transformations, as well as AI-powered innovations on climate-relevant advances and breakthroughs.

For example, AI personalization could encourage sustainable consumption, but it could also increase demand for resource-intensive goods. And disentangling the emissions impacts of AI-enabled innovations from other technologies that lower emissions, such as renewables or carbon capture, will be challenging because the pace of research and development differs across sectors. Policies and regulations are also often slow to catch up. Quantifying the interplay of these dynamics will be difficult.

Comparing and replicating scenarios will be key to improving them as AI systems are rolled out. Researchers should regularly run comparisons between different models for direct and indirect AI-related emissions, coordinated through platforms used by the climate community, such as the Energy Modeling Forum and the Integrated Assessment Modeling Consortium. Scientists must ensure that the data and assumptions in these analyses are fully documented, freely shared and completely replicable by others.

Share data. Data availability is a challenge — especially for fast-moving industries such as AI, in which data are often private or tied to proprietary information. For example, more data are needed on AI workloads in large cloud-computing companies, their electricity and carbon intensity, and trends in efficiencies gained for building and using AI models.

Methods to safely and openly share representative, measured, aggregated and anonymized data without compromising sensitive information are needed. AI can build on examples from other industries — such as the Getting the Numbers Right initiative, which keeps track of carbon dioxide and energy performance indicators in the global cement industry, and the Solomon Energy Intensity Index for fuel refining and pipelines.

Standards should be established for measuring, reporting, verifying and disseminating AI-related data, to ensure both quality and broad accessibility. Recent legislation, such as the European Union’s AI Act and the European Energy Efficiency Directive, could help to drive the development of standards. Although neither regulation directly mandates specific reporting on AI energy consumption, their emphasis on data-centre transparency and efficiency could promote the development of reporting standards.

Issue rapid updates. AI technology is advancing so quickly that scenarios will need to be revised at least once per year, and ideally twice. This is more frequent than is currently done for climate-change scenarios, which are updated every 6–7 years. Annual or biannual updates will be challenging, given the need to collect new data and to develop analytical frameworks as AI systems, applications and breakthroughs emerge.

Because of the potential for AI to either reduce or increase energy demand, researchers must update models that represent societal demand for energy, as well as explore how this demand will change as AI technologies evolve. Scenarios with varying resolutions might be released on different time frames. For example, coarse-resolution scenarios might be updated every few months; more-detailed scenarios could be released every 2–3 years.

Build an international consortium. An international consortium needs to be set up to undertake the development of AI-driven emissions scenarios. It should gather specialists from around the world and represent all the relevant disciplines — from computer and sustainability science to sociology and economics. We suggest this AI-driven emissions-scenario community be co-sponsored by international scientific networks that focus on sustainability, such as the International Institute for Applied Systems Analysis (IIASA) in Laxenburg, Austria, and by international non-governmental organizations focused on AI and society. Examples include the Partnership on AI or the newly established UN Futures Lab, which has been set up to coordinate and improve strategic foresight across the UN to guide long-term decision making.

Consortia that are associated with key IAM and energy-systems models, such as the IEA Technology Collaboration Programme or the IIASA’s programmes, could ensure both open access to data and models, and immediate relevance to the broader climate-scenario modelling communities. The UN and other bodies, such as the International Telecommunication Union in Geneva, Switzerland, should be engaged — but without compromising on the need for agility and speed.

Financial support will be needed to maintain the consortium and support the regular update of scenarios. This could come from a combination of philanthropic, private, governmental and intergovernmental sources.

AI is one of the most disruptive technologies of our time. It’s imperative that decisions around its development and use — today and as it evolves — are made with sustainability in mind. Only through developing a set of standard AI-driven emissions scenarios will policymakers, investors, advocates, private companies and the scientific community have the tools to make sound decisions regarding AI and the global race to net-zero emissions.

Nature 628 , 718-720 (2024)

doi: https://doi.org/10.1038/d41586-024-01137-x

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Competing Interests

A.L., J.L.F. and E.H. are employed by Microsoft, which builds and runs AI models. J.K. and O.G. received some funding from Microsoft to support their work on this article.

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EXPLAINER: Are we making real progress towards 'net zero' emissions?

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Many countries and companies have set 'net zero' goals to curb global warming - but they are still too weak to kickstart the huge changes needed in how we live, work and play

BARCELONA, June 13 (Thomson Reuters Foundation) - Governments, cities and companies are rushing to set the net-zero emissions goals scientists say must be met by mid-century to keep global warming to agreed limits - but achieving them is another matter.

A new analysis by the Net Zero Tracker research initiative notes that in the last few years interest in setting such targets has "exploded" – but "an alarming lack of credibility still pervades the entire landscape", it warned.

"This is problematic because if some of the targets disguise inaction, it can create a false sense of progress," said the June report from the UK-based Energy & Climate Intelligence Unit, Data-Driven EnviroLab, NewClimate Institute and Oxford Net Zero.

Many of the goals - especially those set by business - lack transparency, cover only limited types of emissions, rely too heavily on carbon offsetting or have no interim milestones to stay on track, it added.

What does the growing global enthusiasm for "net zero" mean and what is its importance for the climate and our economies?

WHY DOES 'NET ZERO' MATTER?

It may have become a buzzword in the world of climate action, but scientists and policy makers say it's key to keeping us safe from harm as the planet warms.

The U.N. climate science panel has said man-made carbon dioxide emissions need to fall by about 45% by 2030, from 2010 levels, and reach "net zero" by mid-century to give the world a good chance of limiting warming to 1.5 degrees Celsius and avoiding the worst impacts of climate change.

Under the 2015 Paris Agreement, nearly 200 countries said they would act to curb the rise in global average temperatures to "well below" 2 degrees Celsius above pre-industrial times and strive to keep it to a ceiling of 1.5C.

But the world has already heated up by about 1.1C and is set for warming of close to 2.5C this century, even if current pledges to rein in still-rising emissions by 2030 are implemented, researchers estimate.

In May, the World Meteorological Organization warned there is a 50:50 chance of the average global temperature temporarily reaching 1.5C above the pre-industrial level for at least one of the next five years – and that likelihood is increasing with time.

Should that happen, it would not mean the Paris accord limits have been broken but it would be a precursor of what the world could be like if they are.

Scientists say surpassing 1.5-2C of warming for a longer period of time would bring worsening extreme weather and potentially catastrophic sea level rise, making some parts of the planet uninhabitable and fuelling hunger and migration.

These risks - and mounting public pressure to act on climate change threats - are why a fast-rising number of countries, companies and others are promising to cut their planet-warming emissions to net zero by 2050 or soon after.

If the mid-century net-zero goals set so far are actually met, global warming could be kept to about 1.8C, analysts say.

But some climate activists have criticised 2050 net-zero goals for enabling countries and companies to postpone emissions reductions until a vague far-off date.

WHAT IS NET ZERO?

Achieving net-zero emissions isn't the same as eliminating all emissions.

It means ensuring any human-produced carbon dioxide (CO2) or other planet-warming gases that can't be avoided or locked up are removed from the atmosphere some other way .

This can be done naturally, such as by restoring forests that suck CO2 out of the air. It can also be done using technology that captures and stores emissions from power plants and factories or directly pulls CO2 from the atmosphere.

Planting more trees worldwide is a popular way to absorb and store more carbon, but human-made technologies that perform the same job remain expensive and have yet to be deployed on a large-scale.

Scientists say carbon "removals", in any form, cannot substitute for cutting greenhouse gas emissions as fast as possible - although some removals are likely to be needed and deployed to help curb rising temperatures.

There is fierce debate around the growing enthusiasm for carbon offsetting - where governments, companies and individuals pay for their emissions to be compensated by clean energy and conservation projects that reduce CO2 emissions elsewhere. Those emissions cuts are then counted as part of the government, company or individual’s own carbon-cutting efforts.

WHO HAS COMMITTED TO NET ZERO?

At a country level, the picture is improving, according to the latest Net Zero Tracker report, but things are advancing more slowly among businesses and cities.

National government net-zero targets now cover 91% of global GDP, up from 68% in December 2020, and represent at least 83% of global greenhouse gas emissions, with about two-thirds of those goals enshrined in law or policy documents.

Only 10 countries have set target years later than 2050 but they include some of the world’s biggest emitters – including China’s 2060 pledge and India’s 2070 commitment. Those 10 countries are responsible for about 55% of all emissions by countries with net zero targets, the researchers said.

Large cities are lagging, with 235 having set a net-zero target, mainly in rich countries in North America, Europe, and Asia - but more than 900 have yet to do so.

More than a third of the world’s largest publicly traded companies, meanwhile, now have net-zero targets - up from a fifth in December 2020 - but 65% of corporate targets do not yet meet minimum reporting standards, said the latest Net Zero Tracker report.

Europe is doing best in terms of the proportion of companies with net-zero targets, with 58%, compared with 36% in North America and 20% in East Asia.

But a February report from the NewClimate Institute and Carbon Market Watch warned that net-zero and carbon-neutral pledges can hide a multitude of sins, and there is a need for more information to allow consumers to work out which amount to little more than “green-washing”.

The analysis looked at 25 of the world’s largest corporations, many of them household names – from Amazon to IKEA, Carrefour and Google – and found their net-zero pledges amounted to future emissions reductions, often decades from now, of an average of just 40%.

The problems identified range from a lack of specific emissions reduction targets to vagueness around which parts of the supply chain are covered and the use of carbon credits to offset company emissions instead of efforts to cut them. 

HOW DO YOU SET A CREDIBLE NET-ZERO TARGET?

The World Resources Institute (WRI) and the 2050 Pathways Platform - which work with governments and others on their climate commitments - say cutting emissions within national boundaries should be the priority, with efforts to offset what remains considered only after that.

Currently, only a few governments explicitly aim to use offset credits outside of their jurisdiction to meet their net zero targets or reserve the right to do so: 17 out of 128 countries; 15 out of 115 states and regions; and 39 out of 235 cities, according to Net Zero Tracker.

The share is far higher for corporations at nearly 40%, especially among those targeting net-zero emissions for earlier dates such as 2030. Less than 2% of companies have explicitly ruled out their use, leaving close to 60% that have not specified whether or not they plan to rely on offsetting.

To be credible, net-zero targets should cover all greenhouse gases, including methane, and all economic sectors, as well as international aviation and shipping, WRI says.

Plans for net-zero emissions should be achieved by 2050 or earlier, with the highest-emitting countries doing the most, fastest - and they should be crafted in consultation with those they will affect and clearly communicated, WRI recommends.

The steps needed to get to net zero should be incorporated now into ambitious 2030 emissions reduction targets in national plans and reflected in everyday decision-making, to avoid new investments in high-carbon technologies and infrastructure, according to WRI researchers.

Company net-zero targets often cover very different sources of emissions, with different baselines, and can be challenging to compare, though the Science Based Targets initiative (SBTi) has released guidelines to help remedy that.

This year, U.N. chief António Guterres launched a high-level expert group to help develop stronger and clearer standards for net-zero pledges by businesses, investors and local governments, as well as to verify progress towards them and accelerate their implementation through new rules and regulations.

The U.N.-led "Race to Zero" campaign, launched on World Environment Day in June 2020, also unites businesses, cities and other organisations that aim by around mid-century to cut their planet-heating emissions to net zero.

With a growing focus on the robustness of those commitments, Race to Zero members must meet stringent criteria, including submitting a plan in line with climate science and setting interim targets to reduce emissions.

This explainer was updated on June 13, 2022, with new information on the growth in net-zero targets from the latest Net Zero Tracker analysis.

Related stories:

IN FOCUS - Achieving net-zero emissions

Consumers left in the dark as corporate net-zero plans fail to add up

More net than zero: Do carbon-cutting promises add up for the climate?

Meaningless or sensible? Net zero by 2050 divides climate community

(Reporting by Megan Rowling @meganrowling; editing by Laurie Goering. Please credit the Thomson Reuters Foundation, the charitable arm of Thomson Reuters, that covers the lives of people around the world who struggle to live freely or fairly. Visit http://news.trust.org/climate)

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Net-Zero Emissions: Winning Strategy or Destined for Failure?

Net-zero emissions — balancing emissions by absorbing equivalent amounts of CO2 from the atmosphere — is the defining approach of international climate efforts. But some scientists are arguing that this strategy simply allows the perpetuation of the status quo and is certain to fail.

By Fred Pearce • May 25, 2021

Net zero. Those two words have become the near-universal language for policymakers intent on sealing a deal at the UN climate conference in Glasgow, Scotland in November. But are they the key to fulfilling the promises to hold warming to 1.5 degrees made at a similar climate summit in Paris six years ago, or, as some scientists and activists are now saying, are they a dangerous delusion to which climate scientists have become complicit?

Achieving “net zero” requires that any carbon dioxide or other greenhouse gas emissions are balanced by absorbing an equivalent amount of CO2 from the atmosphere — sometimes called negative emissions. More than 100 countries, including the biggest three emitters — China, the United States, and the European Union — have pledged to achieve net-zero targets in the coming decades. They are being applauded for finally getting a grip on climate change.

But while the net-zero strategy has united policymakers, it has divided climate scientists and activists. Some see the rush to make net-zero pledges in the run-up to Glasgow as a huge success for climate action. But in a blistering commentary last month, a former chair of the Intergovernmental Panel on Climate Change (IPCC), Robert Watson, and two co-authors denounced net zero as a trap set by industrialists and governments to hoodwink the world and lambasted climate researchers for showing “cowardice” in not calling them out.

Net-zero “helps perpetuate a belief in technological salvation and diminishes the sense of urgency,” the critics write.

The hope is that allowing negative emissions to balance continued CO2 emissions as part of net-zero policies will provide a safety net for industries where it is technically impossible to eliminate all emissions — in aviation and agriculture, for instance. The negative emissions might be achieved by increasing CO2 take-up by forests and other ecosystems, or by using industrial chemistry to capture CO2 from the air. But some fear the safety net will become a cover for business-as-usual in highly polluting industries.

The debate is as much about the politics of driving down emissions as about climate science or the potential of technology.

Watson was chair of the IPCC from 1997 until 2002, when the U.S. administration of President George W. Bush refused to nominate the former NASA climate scientist for a second term. Since then he has worked as an academic, currently at the University of East Anglia. He and his co-authors wrote last month that while net zero might be “a great idea, in principle,” in practice it “helps perpetuate a belief in technological salvation and diminishes the sense of urgency surrounding the need to curb emissions now.” Scientists who support the current push for net-zero, they contend, have “licensed a recklessly cavalier ‘burn now, pay later’ approach, which has seen carbon emissions continue to soar.”

Watson and his colleagues admit to their own roles. “We admit that it deceived us,” he and fellow climate scientists James Dyke of Exeter University and Wolfgang Knorr of Lund University in Sweden wrote. But “the time has come to voice our fears and be honest with wider society… Current net zero policies will not keep warming to within 1.5 degrees, because they were never intended to. They were and still are driven by a need to protect business as usual.”

Watson’s stand — especially coming from a former IPCC boss — has angered some fellow researchers. In a riposte published this month, Richard Black at Imperial College London said it makes little sense to attack net zero when it is “the defining lens through which many governments, businesses, NGOs and other types of entity view decarbonization.” Black told Yale Environment 360 , “high-carbon advocates have always found excuses to delay, and would do so whatever the policy framing.” But “it has nothing to do with net zero per se .”

Steam turbines at a carbon-capture-and-storage pilot project at the Mountaineer coal-burning power plant in West Virginia in 2009. The project was discontinued in 2011. SAUL LOEB/AFP via Getty Images

In any case, Black is upbeat. In March, he was lead author of an analysis of net-zero commitments that argued that “the global momentum on net zero represents an exciting window.” Besides 124 national governments committing to adopting various versions of net zero as targets, he found net-zero pledges from more than 1,500 major companies, representing $14 trillion in revenues.

Black agrees that not all these governments and businesses intend to honor their pledges. And auditing whether they do so is particularly difficult where those pledges involve offsetting their continued emissions by buying paper certificates from other organizations that claim to have prevented emissions elsewhere or absorbed CO2 in forests.

“There are big flaws in how net zero is being implemented in some cases,” Black said. “But pledging a target means that the entity can be held to account by voters, shareholders, or customers.”

This is happening, Black says. He cites the example of the German government. Last month the country’s highest court ordered it to up its short-term emissions reductions to ensure that its mid-century net-zero target did not leave a disproportionate share of the responsibility to future generations.

Industries too will be judged. The fossil-fuel industry’s public commitments to net zero by 2050 will from now on be compared with a detailed road map for achieving net zero across the energy industry published this month by the International Energy Agency (IEA), an intergovernmental body long considered by environmentalists as an apologist for fossil fuel companies.

If properly designed, nature-based solutions “can have a powerful role in reducing temperatures,” a new analysis says.

No longer. The IEA now says that meeting net zero requires an immediate worldwide end to approvals of new oil and gas fields — meaning all drilling for more oil or gas reserves should cease. This puts it at odds with oil giants that are promoting corporate net-zero strategies while continuing to search for more oil.

These include Shell. Its shareholders this month endorsed a strategy for making its business net zero by 2050. But a minority protested that the strategy contravenes the IEA’s call to end all fossil-fuel expansion now. Instead, the Shell plan anticipates a 20-percent increase in gas production by 2030.

Shell’s version of achieving net zero relies heavily on investment in forest projects to offset its emissions. Several have already proved controversial. Following an analysis of the company’s net-zero strategy that they coauthored, Johan Rockstrom of the Stockholm Resilience Center and Gail Whiteman of the University of Execter said the negative emissions that Shell will need to offset its continued fossil-fuel activity “requires a forest the size of Brazil.”

Rockstrom and Whiteman call for the company to be drummed out of net-zero initiatives, such as the UN’s Race to Zero campaign, and questions its role advising the British government in the run-up to the Glasgow climate conference.

IEA director Fatih Birol also says net zero requires a global program for early shutdown of coal-fired power stations, especially in Asia. Yet signatories to net-zero policies, including the government of China, continue to fund new coal-plants, as do major finance houses such as Barclays and BNP Paribas, despite both joining a UN Net-Zero Banking Alliance.

A coal-fired power plant in Yokohama, Japan. Associated Press

Some environmental NGOs, such as The Nature Conservancy, nonetheless back net zero and have created their own offsetting projects to help companies take advantage of emission offsets. But others decry it. Friends of the Earth calls it “chasing climate unicorns,” allowing polluters to “hide behind the ‘net’ in net zero, claiming that they just need to pay someone else to remove carbon.”

Dyke told e360 : “Net zero policies are best understood as the latest manifestation of a dysfunctional climate policy system” — the latest “framing” by apologists for the status quo.

He believes the slippery slope began in the 1990s when there was a push to persuade a reluctant U.S. to address climate change by allowing it to count the carbon absorbed by its forests as a contribution. The idea, says Dyke, was that “if it managed its forests well,” then the carbon stored “should be subtracted from its obligations to limit the burning of coal, oil, and gas.“

Technological fixes followed. At the climate conference in Copenhagen in 2009, companies promised to develop carbon capture and storage (CCS), the capture of CO2 as it went up power-station stacks for burial underground. But a decade on, he says, there are no such facilities in practical large-scale operation.

By Paris in 2015, the “new savior technology” was Bioenergy with Carbon Capture and Storage (BECCS). This combined CCS with burning wood or other bioenergy crops in power stations. If the wood or other fuel was then regrown, it would absorb more carbon from the air. In this way, the world could combine generating energy and negative emissions.

As part of C02 reduction strategies, some countries are claiming natural processes already included in future climate models.

But since Paris, it has emerged that full deployment of BECCS would require frequently harvested tree plantations or bioenergy crops covering anywhere from 25 to 80 percent of all land currently under cultivation. That would “devastate biodiversity,” according to Watson, who since his stint at the IPCC has also chaired the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services.

“The end result of all these diversions,” Dyke said, “has been the same — no effective mitigation.” Emissions today are 60 percent above the level of 1992, the year the world first agreed at the Rio Earth Summit to prevent “dangerous” climate change. ”Net zero is just the latest example of wishful thinking that effectively stops us critically reflecting on why we have failed,” he said.

In the search for means of achieving negative emissions to meet net-zero targets, there has been an increasing focus on what are called “nature-based solutions.” These involve using forest planting or restoration of carbon-holding wetlands, such as peat bogs or mangrove swamps, to draw CO2 from the air.

The term was coined in 2017 by Bronson Griscom, then at The Nature Conservancy. In a new analysis by him and others in the journal Nature this month, Griscom says they “can have a powerful role in reducing temperatures,” including in the long term, if they are properly designed and have good accounting standards.

But this too has drawn the ire of Watson and his co-authors. Knorr told e360 that while it was true that restored ecosystems can hold more carbon, calculating any additional benefit from short-term interventions is all but impossible. It is also wide open to misrepresentation, he said, as companies and countries adopt natural carbon sinks as part of their plans for net zero.

Mangroves on the Osa Peninsula of Costa Rica. Mangrove forests are major carbon sinks. Prisma by Dukas Presseagentur GmbH/ Alamy Stock Photo

“About a third of current CO2 emissions are taken up by forests and other ecosystems,” Knorr said. “Double counting is essentially unavoidable. We need the natural sink plus mitigation, not the sink as mitigation.”

Potentially even worse, he warns, climate change itself “could weaken forests and make them prone to fires or insect attacks,” at which point they start releasing their carbon. For such reasons “nature-based solutions don’t offer a guarantee that carbon will remain stored away. It’s a Pandora’s box,” Knorr said.

Climate modeler Myles Allen at Oxford University, a co-author of this month’s Nature paper on nature-based solutions, agrees. Climate-based solutions are “temporary and at risk of reversal as the world warms,” he told e360 . Most climate models show the biosphere switching from as sink to a source of carbon over the course of this century. “So storing fossil carbon there is risky,” Allen said, “unless you have a plan to re-store it somewhere permanently if it starts to leak out again — which no offsetting schemes even think about.”

Such concerns have not stopped some countries from including their natural sinks in calculating their contributions to climate change. Bhutan and Suriname both claim to be carbon negative because their trees currently absorb more than their industries emit. But this makes no scientific sense, says critics, because they are claiming as part of their CO2 reduction strategies natural processes that are already included in models of future climate. The danger is that other countries may try to join them.

When China recently committed to achieving net zero by 2060, it said that it would achieve this in part through nature-based solutions. The government’s special envoy of climate, Xie Zhenhua, said in 2019 that nature-based solutions could cut China’s net emissions by a third. Last year, in a Nature paper, Yi Liu of the Chinese Academy of Sciences and colleagues calculated that between 2010 and 2016 China’s forests soaked up the equivalent of 45 percent of its human-made CO2 emissions.

Similarly, the U.S. Forest Service says 11 percent of national CO2 emissions are “offset” by American forests. If the world’s two biggest emitters start claiming that the carbon being absorbed in these existing forests could be offset against their emissions to achieve net zero, then the scientific basis for net-zero policies to end climate change would swiftly unravel.

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Global net-zero emissions goals: Challenges and opportunities

To avert the worst impacts of climate change, from extreme flooding to devastating droughts, the world will need to cap global warming at 1.5 degrees Celsius, according to the latest United Nations  IPCC Report  on the Earth’s climate system. Achieving that goal means that by around 2050, the planet’s total greenhouse gas emissions will need to decline to  net-zero . To that end, more and more governments and businesses are setting net-zero emissions targets.   

At the XLIV (44th) MIT  Global Change Forum  on March 23-24, 2022, more than 100 attendees from industry, academia, government and NGOs gathered at the Samberg Conference Center on the MIT campus and on Zoom to explore how global net-zero emissions goals are creating challenges and opportunities for carbon budgets, decarbonizing energy and industry, nature-based solutions, climate and health, negative emission technologies, and policy design. Facilitated by the  MIT Joint Program on the Science and Policy of Global Change  in an informal, “off-the-record” setting for independent assessment of studies and policy proposals, presentations and discussions examined this year’s Forum theme from a variety of perspectives.

"We meet at a time when the urgent need to transition to a net-zero-greenhouse-gas-emitting world is made even more complex by the global COVID-19 pandemic, the premature acceleration of climate extremes, and now the Russian invasion of Ukraine,” said MIT Joint Program Director  Ronald Prinn , a professor at MIT’s Department of Earth, Atmospheric and Planetary Sciences in his opening remarks. “New questions now arise such as how an emerging case for security in national energy supplies may help or hinder the net-zero transition. As the complexity grows, the need for deep-dive modeling of complex interacting human and natural systems that is the hallmark of the Joint Program on the Science and Policy of Global Change is becoming more and more evident."

Here, with permission from all speakers, we summarize key points from this year’s Forum presentations.

Carbon Budgets

The first session explored the concept of carbon budgets and how it can be applied in the design of strategies aimed at achieving net-zero-emissions.

One common definition of a carbon budget is “the total net amount of carbon dioxide (CO 2 ) that can still be emitted by human activities while limiting global warming to a specified level.” The impetus for estimating the Earth’s “remaining-carbon budget” is that concentrations and growth rates of CO 2 —the main driver of long-term anthropogenic climate change—are the highest they’ve been in millions of years. The latest IPCC Report estimates that there’s a 50% probability that we can limit global warming to 1.5°C (or 2°C) starting in 2020 with a carbon budget of about 500 gigatons (Gt) (or 1,350 Gt) of CO 2 . Another carbon budget definition quantifies exchanges and storage of carbon between and within global land, ocean and atmosphere systems. While about half of CO 2  emissions get sequestered in land and ocean systems, the remaining half ends up in the atmosphere where it largely warms the global climate along with other, shorter-lived greenhouse gas emissions such as methane. In recent years, the ability of the land and oceans to store CO 2  has showed signs of weakening, a trend consistent with El Nino Southern Oscillation events and evidence of climate-warming impacts from Earth-system models.

To estimate a remaining-carbon budget, the IPCC considers: historical warming to date (about 1.1°C), transient climate response to cumulative emissions of CO 2 , zero-emission commitment (how much warming might still occur if emissions go to zero), projected future non-CO 2  temperature contribution, and unrepresented Earth-system feedbacks—all accompanied by uncertainty ranges. Estimated carbon budgets determine how much CO 2  can still be emitted in order to align with a specified climate target. They also provide the scientific basis for net-zero targets. While many of today’s announced net-zero targets are imprecise, they can be improved by providing clarification on scope, adequacy and fairness, and the long-term roadmap for achieving the target. By using cumulative emissions until net-zero to design mitigation pathways, limitations of the current scenario literature can be overcome—reducing the risk of exceeding maximum temperature limits and limiting the burden on future generations to remove large quantities of CO 2  from the atmosphere.  

Decarbonizing energy and industry

The second session focused on how the energy and industry sectors can effectively and efficiently reduce greenhouse gas emissions in alignment with net-zero emissions goals.

The energy sector contributes about 73 percent of global greenhouse gas emissions. To achieve net-zero emissions by 2050, the sector must decarbonize at an unprecedented pace. But to be deployed at scale, zero-carbon energy technologies must not cause significant increases in energy prices and declines in energy access. Among these are wind and solar, which now account for two percent of global primary energy use and must increase dramatically. The MIT Joint Program, most notably in its  2021 Global Change Outlook , has explored different emissions pathways and risks in the coming decades. Its most ambitious climate policy scenarios show a substantial decline in fossil fuel use, and significant increases in wind and solar, and in electrification. A wide range of future technologies will be needed to get to net-zero, from advanced nuclear power to direct air carbon capture. Critical minerals will be in greater demand for the clean energy transition, and obtaining sufficient quantities could be a challenge .

A recent net-zero emissions (NZE) scenario prepared by the International Energy Association (IEA) shows that dramatic reductions in industrial CO 2  emissions will be needed to achieve net-zero emissions from the energy sector by 2050. One key challenge is posed by heavy industries—primarily steel, cement and chemicals—particularly in emerging market and developing economies, where they are expected to produce the majority of industry-sector emissions in 2050. Heavy industries use large amounts of fossil fuels, especially to generate high-temperature heat for industrial processes. The IEA NZE scenario shows that interventions at end of the next 25-year capital investment cycle could prevent the release of about 60 gigatons of cumulative CO 2 , around 40% of projected emissions from existing heavy industry assets. While direct substitution of electricity at the scale required is impractical or expensive with today’s technologies to reduce heavy-industry emissions, innovative technologies such as hydrogen and carbon capture utilization and storage could play a critical role.

Nature-based solutions

The third session examined how nature-based solutions (NBS) can contribute to global efforts to achieve net-zero emissions.

The World Conservation Union defines nature-based solutions as “actions to protect, sustainably manage, and restore natural or modified ecosystems, that address societal challenges effectively and adaptively, simultaneously providing human well-being and biodiversity benefits.” NBS opportunities include protecting natural ecosystems, restoring degraded ecosystems, and more sustainably managing ecosystems used for food, fiber and energy production. One NBS method, reforestation, could deliver substantial CO 2  sequestration, but also intensify competition for land-based food production. Agroecological farming, another NBS approach, may store 20-33% more soil carbon than conventional agriculture, but runs the risk of mal-adaptation and mal-mitigation. Finally, systems to monitor and measure carbon sequestration will be needed to determine how much to pay NBS providers for the environmental services they perform. 

NBS that is implemented within large-scale systems and in ways that also meet human needs can be at least as additional and “permanent” as reductions in fossil fuel extraction. To that end, there is an urgent need to act now on deforestation to avoid nearly irreversible loss. Beyond avoiding tropical deforestation, there is a lot of global potential for NBS carbon storage through afforestation/reforestation, and soil carbon sequestration in croplands and grasslands. NBS could contribute 29% of net reductions needed to be on a 2°C pathway in 2030, but one key challenge is to make NBS crediting programs effective and equitable. In one analysis, the global use of carbon markets with forest-based NBS could allow nearly doubling of climate ambition at the same cost, relative to current Paris Agreement pledges. Jurisdictional approaches to forest protection, in which deforestation is reduced through national or regional-scale forest protection programs, could provide high-integrity credits from avoiding tropical deforestation.

Climate and health

The fourth session centered on efforts to formulate integrated emissions-reduction policies that not only help stabilize the climate but also improve air quality and public health outcomes.

Fine particulate matter (PM 2.5 ) resulting from the combustion of fossil fuels contributes to more than 25 percent of all air pollution-related deaths globally. The use of solid fuels (wood, charcoal and animal dung) in residential settings is another major contributor to air pollution-related health impacts. Policies that accelerate a transition away from fossil fuels and toward clean energy sources could improve air quality and public health outcomes considerably while simultaneously advancing climate goals. The changing climate is expected to increase public health vulnerability and costs, underscoring the need to incorporate air quality and health concerns in climate action. Key questions that can advance integrated air pollution, public health and climate policies are: What are the major sources of air pollution and greenhouse gases, and how do they contribute to health impacts; what are their relative contributions to disease burdens; and what actions are needed to achieve substantial improvements in the future?

Previous research in this space separated “direct” from “indirect” benefits of climate policies, framing improved health outcomes as “co-benefits” of such policies. But a more holistic approach to policy design could advance an integrated set of objectives based on questions such as: What are the observed impacts of climate and energy policies on air quality? Who benefits and why (including assessment of environmental justice and equity)? What strategies can promote well-being for the present and future (and what new methods and models are needed to evaluate options)? This approach could yield new insights on proposed energy, climate and air pollution policies such as: health impacts may depend on local responses to policy; and maximizing overall benefits at the national level may not address disparities at subnational levels. New models and methods can facilitate multi-dimensional assessment (e.g. of multiple indicators/outcomes relevant to sustainability) of policy strategies on different scales. 

Keynote address: MIT Grand Climate Challenges

The keynote address highlighted the  MIT Grand Climate Challenges  initiative, which seeks to “mobilize the MIT research community to develop game-changing solutions to the most challenging unsolved problems in climate adaptation, mitigation and restoration.” Engaging all disciplines across MIT, the initiative aims to draw on the MIT innovation ecosystem and develop new partnerships with multiple communities, businesses and investors to accelerate development, field-testing, implementation and scaling of these solutions. Twenty-seven finalist projects represent four themes: building equity and fairness into climate solutions; removing, managing and storing greenhouse gases; decarbonizing complex industries and processes; and using data and science to forecast climate-related risk. In the spring of 2022, MIT will announce a small number of flagship projects from among the 27 finalists.

Negative emission technologies

The fifth session explored the potential of negative emission technologies to enable the world to meet net-zero emissions and long-term Paris Agreement climate targets.

Negative emission technologies (NETs) are those that physically remove carbon dioxide from the atmosphere and store it in a manner intended to be permanent, with the total quantity of stored CO 2  exceeding the total quantity of CO 2  emitted or leaked into the atmosphere by the NET. NETs include afforestation and reforestation, soil carbon sequestration, biochar, bioenergy with carbon capture and storage (BECCS), direct air capture, enhanced weathering and ocean alkalinization, and ocean fertilization. NETs are not an alternative to greenhouse gas mitigation methods, but a complementary toolset to help ensure that emissions and climate targets are met. How much the world will need to rely on NETs to meet those targets will depend on how late it starts to aggressively mitigate emissions at the global level. Within the portfolio of NETs, no one method is a silver bullet. To ensure climate stabilization, NETs must be deployed in such a way that the CO 2  that they extract from the atmosphere is removed permanently and is subject to effective measurement, reporting and verification (MRV) protocols.

A study of BECCS designed to quantify its potential scale and impact on the economy under 1.5°C or 2°C scenarios   shows that in 2100 without BECCS, total primary energy (TPE) is 33-38 percent of what it would be in a business-as-usual (BAU) scenario; with BECCS, TPE nearly reaches BAU levels, with emissions from oil use offset by BECCS. When it comes to net CO 2 -equivalent emissions under a 1.5°C or 2°C scenario, without BECCS the world will need significant additional emissions reductions; with BECCS it will have a lot more “headroom” to achieve the same emissions pathway. The study shows that BECCS significantly reduces the cost of meeting long-term targets, causes significant land-use change, but only increases food prices by about 1.5 percent. All technical components for large-scale BECCS now exist, but many challenges, from availability of sustainable biomass to public acceptance, could limit its deployment. Other research indicates that when designing climate-stabilizing emissions pathways, one must consider the full range of options (no NETs to multiple NETs) for risk assessment and planning.

Policy: The way forward

The sixth and final session explored the design and implications of policies aimed at achieving net-zero emissions targets, with a focus on the near-term actions needed to get there.

Prospects for greenhouse gas (GHG) mitigation in the United States improved in 2021 with the passage of the Infrastructure Investment and Jobs Act and the House of Representatives’ passage of the Build Back Better (BBB) Bill. Stalled in the Senate, BBB would earmark $555 billion for measures aimed at reducing GHG emissions 50-52-percent below 2005 levels by 2035. While the bill focuses on many sectors of the economy, it would reduce emissions the most in the transportation and electricity sectors.

Meanwhile, the European Green Deal led to the enactment of a European Union law that seeks climate neutrality by 2050 and sets the EU’s Paris Agreement target for 2030 to at least 55 percent below 1990 GHG emissions levels. The EU also introduced a “Fit for 55” package of 16 legislative proposals aligned with that target, and a Sustainable Finance Framework to re-orient capital flows toward sustainable investment. Finally, the EU is working to phase out dependence on Russian fossil fuel imports.

Recent successes in decarbonizing the energy sector provide lessons for mitigation of GHG emissions in agriculture, forestry and other land use (AFOLU). What has accelerated decarbonization in the power sector—technical advances, simulation modeling, policy support and institutional innovation—might also bring about the level of innovation and investment needed to substantially cut GHG emissions in AFOLU. Accounting for about 21 percent of global GHG emissions in 2018, AFOLU is a major source of methane emissions, and is the only sector with significant potential to deliver net-negative emissions.

In 2020, the Governor of the Commonwealth of Massachusetts committed the state to a 2050 net-zero greenhouse gas emissions goal; in 2021 he signed into law  An Act Creating a Next Generation Roadmap for Massachusetts Climate Policy , which codified that goal. Analysis conducted by the Massachusetts Executive Office of Energy and Environmental Affairs found that the state could achieve the 2050 goal cost-effectively and equitably. Strategies include deployment of large-scale offshore wind, importation of additional hydropower, and decarbonization of home heating systems and private vehicles—and ensuring that the needed green technologies are adopted by and affordable for everyone.

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• Explainer: Will global warming ‘stop’ as soon as net-zero emissions are reached?

Zeke Hausfather

Media reports frequently claim that the world is facing “committed warming” in the future as a result of past emissions, meaning higher temperatures are “ locked in ”, “ in the pipeline ” or “ inevitable ”, regardless of the choices society takes today.

The best available evidence shows that, on the contrary, warming is likely to more or less stop once carbon dioxide (CO2) emissions reach zero, meaning humans have the power to choose their climate future.

When scientists have pointed this out recently, it has been reported as a new scientific finding. However, the scientific community has recognised that zero CO2 emissions likely implied flat future temperatures since at least 2008 . The Intergovernmental Panel on Climate Change (IPCC) 2018 special report on 1.5C also included a specific focus on zero-emissions scenarios with similar findings. 

Much of the confusion around committed warming stems from mixing up two different concepts: a world where CO2 levels in the atmosphere remain at current levels; and a world where emissions reach net-zero and concentrations begin to fall.

Even in a world of zero CO2 emissions, however, there are large remaining uncertainties associated with what happens to non-CO2 greenhouse gases (GHGs), such as methane and nitrous oxide, emissions of sulphate aerosols that cool the planet and longer-term feedback processes and natural variability in the climate system. 

Moreover, temperatures are expected to remain steady rather than dropping for a few centuries after emissions reach zero, meaning that the climate change that has already occurred will be difficult to reverse in the absence of large-scale net negative emissions.

Constant concentrations vs zero emissions

The confusion around the impact of zero emissions is understandable. Even a NASA climate FAQ – last updated in 2007 – still says that “even if we stopped emitting greenhouse gases today, global warming would continue to happen for at least several more decades, if not centuries”. (NASA’s Dr Gavin Schmidt tells Carbon Brief that this wording does not reflect more recent research and an update is in the works). 

One common cause of confusion is the mixing up of two very different scenarios: a world where CO2 concentrations remain at today’s levels; and a world where all emissions are immediately cut to zero (or net-zero, which would have the same effect; what ultimately matters is the balance of CO2 sources and sinks, though the extent to which sinks are natural or anthropogenic can be a tricky question ).

Until the mid-2000s, many climate models were unable to test the impact of emissions reaching zero. This is because they did not include modelling of biogeochemical cycles – such as the carbon cycle – and could not effectively translate emissions of CO2 into atmospheric CO2 concentrations.

As a result, climate models tended to be run with scenarios of the concentration of CO2 in the atmosphere, rather than emissions, and often examined what would happen if atmospheric CO2 levels remained fixed at current levels into the future.

These “constant concentration” scenarios showed that there was additional warming “in the pipeline” as the oceans slowly warmed up to reach the same temperature as the atmosphere and brought the Earth back into radiative equilibrium. That is to say, where the amount of energy absorbed by the Earth from the sun is equal to the amount being reradiated back to space.

Models tended to suggest 0.4C to 0.5C or so of additional warming would occur over the next few centuries, if concentrations were kept at the same level. 

However, a world of constant concentrations is not one of zero emissions. Keeping concentrations constant would require some continued emissions to offset the CO2 absorbed by the land and oceans. This would amount to around 30% of current global emissions, although the amount needed would fall over time.

If emissions are cut to zero, on the other hand, atmospheric concentrations of CO2 would quickly fall, before eventually stabilising at a lower level.

The figure below, adapted from a 2010 paper in Nature Geosciences by Prof H Damon Matthews and Prof Andrew Weaver , compares projected temperature changes out to 2200 under scenarios with constant concentrations (red line) and zero emissions (blue).

Matthews and Weaver found that, in a constant concentration scenario, the world would continue to warm by around 0.3C by 2200 – with some additional warming in centuries to come as the deep oceans continued to slowly warm.

Given that the world has already warmed by around 1.3C, this means that the 1.5C limit would be breached, if current CO2 concentrations are held steady due to some continued emissions.

By contrast, they suggested that temperatures would stabilise in a world of net-zero emissions, remaining roughly at the level they were when emissions ceased.

Warming oceans and falling atmospheric CO2

The finding that temperatures would stabilise after emissions reach zero results from two different factors working in the opposite direction.

The Earth is currently out of thermal equilibrium, meaning more energy from the sun is being trapped by the greenhouse gases in the atmosphere than is escaping back to space. Over 90% of this extra heat is going into warming the oceans. However, as the oceans continue to warm, they will take up less heat from the atmosphere and global average surface temperatures will rise further.

At the same time, the land and ocean are absorbing about half of the CO2 that humans emit each year. If emissions go to zero, these “carbon sinks” continue to take up some of the extra CO2 that was emitted in the past – quickly at first and then more slowly over time as they move toward a new equilibrium. This reduces the levels of CO2 in the atmosphere and, thus, the warming it causes. 

By chance, these two factors cancel each other out . The additional surface warming from the oceans continuing to heat up is balanced by the cooling from falling atmospheric CO2.

Both of these factors are also expected to have similar patterns over time, being larger in the first few years after net-zero emissions and gradually tailing off over time.

In the very long run – over many hundreds to thousands of years – carbon sinks would become dominant and global temperatures would eventually fall – as long as anthropogenic CO2 emissions remained at net-zero. The lifetime of CO2 in the atmosphere is determined by how rapidly sinks take up CO2; while about half of our emissions are absorbed relatively quickly, a portion of our CO2 emissions that has accumulated in the atmosphere will still be around in tens of thousands of years.

New results published over the past year offer much stronger evidence of the effect of net-zero CO2 emissions on temperatures. These results come from a set of modern climate models that include carbon cycle dynamics, called Earth system models (ESMs).

The Zero Emissions Commitment Model Intercomparison Project (ZECMIP) used 18 different ESMs to simulate what would happen in a world where global emissions suddenly ceased after the world had emitted a total 3667 Gigatons of CO2 (or 1000 Gigatons of carbon) – which would be expected to result in warming of around 2C compared to preindustrial levels. It also examined a case where emissions gradually decreased to net zero and found similar results to an abrupt cutoff after net-zero is reached.

(ZECMIP is similar to the model intercomparison projects undertaken under the auspices of CMIP6 , the new generation of climate models developed in the lead-up to the IPCC’s sixth assessment report, due to be published in 2021-22. It was designed too late to be part a formal part of the CMIP6 cohort, however.) 

The figure below shows the results from this experiment 50 years after emissions cease. The top panel shows the change in energy flux – the amount of energy accumulating at the Earth’s surface – from different sources. The bottom panel shows the average surface temperature change after 50 years of zero emissions.

The red bars represent warming from reduced ocean heat uptake as the oceans get warmer, while blue and yellow bars represent cooling from CO2 absorption by the oceans and land, respectively. Note that the net forcing in the top panel will not necessarily always match the projected temperature impact, as natural variability and other factors can also affect surface temperature changes in ESMs.

The projected future temperature change 50 years after zero emissions is reached varies from 0.3C of cooling to 0.3C of warming, with an average of around 0.03C of cooling across all of the models participating in the ZECMIP experiments. Ten of the models show expected surface temperature changes close to zero, while three models show notable cooling and two show notable warming.

The different meanings of net-zero emissions

While much of the focus of climate mitigation efforts is on CO2, human emissions of other GHGs and aerosols also have a large impact on global surface temperatures. And whereas global temperatures will stabilise once CO2 emissions fall to zero, the same is not true for zero GHG or aerosol emissions.

The IPCC’s special report on 1.5C (SR15) used a simplified ESM to assess the likely evolution of surface temperatures under different possible definitions of zero emissions. The results of these different scenarios are shown in the figure below.

The report looked at the case examined above – zero CO2 emissions – shown by the blue line. But it also looked at zero CO2 and aerosol emissions (red), zero GHGs (yellow) and zero GHGs and aerosols (purple). 

Human emissions of aerosols – tiny particles of sulfur or nitrogen suspended in the atmosphere that reflect incoming sunlight back to space – have a strong cooling effect on the planet, though there are large uncertainties as to exactly how large this effect is. Aerosols also have a relatively short atmospheric lifetime and, if emissions cease, the aerosols currently in the atmosphere will quickly fall back out.

As a result, the world would be around 0.4C warmer if CO2 and aerosol emissions go to zero, compared to zero CO2 emissions alone. In this scenario (red line), the world would likely exceed the 1.5C target, reaching around 1.75C by 2100.

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Other GHGs are also important drivers of global warming. Human-caused emissions of methane , in particular, account for about a quarter of the historical warming that the world has experienced.

Unlike CO2, methane has a short atmospheric lifetime, such that emissions released today will mostly disappear from the atmosphere after 12 years. This is the main reason why the world would cool notably by 2100 if all GHG emissions fell to zero. This would result in around 0.5C of cooling compared to a scenario where only CO2 falls to zero.

Finally, if all human emissions that affect climate change fall to zero – including GHGs and aerosols – then the IPCC results suggest there would be a short-term 20-year bump in warming followed by a longer-term decline. This reflects the opposing impacts of warming as aerosols drop out of the atmosphere versus cooling from falling methane levels.

Ultimately, the cooling from stopping non-CO2 GHG emissions more than cancels out the warming from stopping aerosol emissions, leading to around 0.2C of cooling by 2100.

These are, of course, simply best estimates. As discussed earlier, even under zero-CO2 alone, models project anywhere from 0.3C of cooling to 0.3C of warming (though this is in a world where emissions reach zero after around 2C warming; immediate zero emissions in today’s 1.3C warming world would likely have a slightly smaller uncertainly range). The large uncertainties in aerosol effects means that cutting all GHGs and aerosols to zero could result in anywhere between 0.25C additional cooling or warming.

Combining all of these uncertainties suggests that the best estimate of the effects of zero CO2 is around 0C +/- 0.3C for the century after emissions go to zero, while the effects of zero GHGs and aerosols would be around -0.2C +/- 0.5C.

There is also a potential for natural variability to play a role in future warming, even under a zero emissions future. A recent paper by Prof Chen Zhou and colleagues suggested that natural cycles in the eastern Pacific have masked some of the warming that would otherwise have occurred from historical emissions.

Zhou and colleagues suggest between 0.2-0.5C of additional warming could occur, even in a zero emissions world, once historical patterns of cold temperatures in this part of the ocean reverse – though only a portion of this warming would likely occur by 2100.

Some other researchers have been sceptical of these conclusions, suggesting that it is unclear if or when these historical patterns in the Pacific ocean might shift.

The studies featured in this piece all look at the effects of zero-emissions scenarios today or in the next few decades. If, however, zero emissions were to occur later in the century, there is the potential to lock in more carbon-cycle feedback processes – such as melting permafrost – than under current global temperature levels.

A world that has warmed by 3C or 4C above pre-industrial levels may lock in more committed future warming than today’s world – and more research is needed to explore these effects. 

Finally, while current best estimates suggest that temperatures will stabilise in a zero-emissions world, that does not mean that all climate impacts would cease to worsen.

Melting glaciers and ice sheets and rising sea levels all occur slowly and lag behind surface temperature warming. A zero-emissions world would still result in rising sea levels for many centuries to come, with some estimates suggesting that at least 80cm of additional sea level rise is “locked in”.

To stop these impacts may, ultimately, require reducing global temperatures through net-negative global emissions , not just stopping temperature from rising by reaching net-zero.

Update: This article was updated on 30/04/2021 to clarify details of the ZECMIP experiment.

• Explainer: Why more global warming is not ‘inevitable’ once we reach net-zero emissions

• DOI: 10.1007/s10668-024-05118-y
• Corpus ID: 270937146

The race to zero emission: Can climate policy uncertainty threaten decarbonization?

• Han Wei , Xianjun Dai , Khalid Khan
• Published in Environment, Development and… 2 July 2024
• Environmental Science, Political Science, Economics

59 References

Beyond borders: assessing the transboundary effects of environmental regulation on technological development in europe, how does climate policy uncertainty affect the carbon market, effects of carbon pricing and other climate policies on co 2 emissions, do climate policy uncertainty and economic policy uncertainty promote firms’ green activities evidence from an emerging market, does technological innovation promote renewable energy investment, does climate policy uncertainty affect carbon emissions in china a novel dynamic ardl simulation perspective, are economic policy uncertainty and carbon futures price interacting evidence from the european union, driving towards a sustainable future: transport sector innovation, climate change and social welfare, 2030 agenda of sustainable transport: can current progress lead towards carbon neutrality, renewable energy, climate policy uncertainty, industrial production, domestic exports/re-exports, and co2 emissions in the usa: a svar approach, related papers.

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Net Zero: explained

During the general election campaign, one of the issues that’s been mentioned is whether the parties will stick to the UK’s 2050 ‘Net Zero’ greenhouse gas emissions target, and how they plan to achieve this. 

In the past we’ve seen several claims on the impact of achieving Net Zero, including some from the Prime Minister Rishi Sunak last autumn when he announced a new approach to achieving the UK’s greenhouse gas emissions targets. 

Mr Sunak said at the time this was a “more pragmatic, proportionate and realistic approach to achieving Net Zero that eases the burdens on working people”.  Others were critical of what they suggested was a “watering down” of the UK’s Net Zero policies. 

But what is Net Zero, and what are the political parties saying about it? This article looks at what we mean by Net Zero, whether the UK is on track to meet its climate targets, and what the parties are saying about this during the election campaign.

This explainer is one of a series Full Fact is publishing ahead of the 4 July general election, exploring a range of topics which feature in the campaign. We’ll be updating these articles on a regular basis—this article was last updated on 2 July 2024 and the information in it is correct as of then.

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What does ‘Net Zero’ mean?

The concentration of greenhouse gases , gases that trap heat in the atmosphere, including carbon dioxide, methane and others, contributes to global warming. The objective of Net Zero is to reduce the amount of these gases in the atmosphere in order to reduce global warming. 

Reaching Net Zero means achieving a balance between greenhouse gas emissions and the amount of these gases removed from the atmosphere by either natural processes such as photosynthesis, or by other methods of carbon capture and storage, leaving ‘net zero’ in the atmosphere. The UK’s legal target , set by the government, is to achieve Net Zero carbon emissions by 2050.

How do you achieve Net Zero?

There are several policies proposed for achieving Net Zero. These include methods for both reducing emissions produced by human activity and increasing the amounts of carbon absorbed from the atmosphere.

Reducing emissions presents a lot of policy choices. About a quarter of the UK’s emissions come from transport, using estimates from 2021, with other key areas including the energy sector (20%), businesses (18%) and households (16%).

Emissions might be reduced by phasing out the use of fossil fuels and increasing the use of renewable sources of energy, such as wind or solar power, for example. 

Carbon emissions from transport can also be reduced by measures including increasing the use of electric vehicles on the roads and further electrification of rail travel . An additional means of reducing emissions is by increasing the efficiency of domestic energy use, such as through improving home insulation and the installation of domestic heat pumps .

The other side to the equation is increasing the amounts of carbon absorbed from the atmosphere. One common method of carbon removal is through planting more trees . Restoring other natural environments, such as peatlands , can also increase the amount of carbon dioxide absorbed from the atmosphere.

What is the government obliged to do?

Under the Climate Change Act 2008, the government is required by law to reduce greenhouse gas emissions. The government is also required to publish carbon budgets every five years setting out caps on emissions. 

In addition, in 2016, the UK signed the Paris Agreement . Signatories to the agreement have pledged to keep the level to which global temperatures are rising to below 2°C and work towards limiting it to 1.5°C.

In 2019, the UK set the current legally binding target to achieve Net Zero emissions by 2050 . In 2021, the government also announced an interim target to reduce emissions by 78% by 2035, compared to 1990 levels.

Both the Conservatives and Labour have said they are committed to achieving the 2050 Net Zero target. Other parties, including the Liberal Democrats and the Green Party , have said they want to achieve Net Zero before 2050. The SNP says it shares the Net Zero ambition for Scotland as well, and legislation gives Scotland a target to achieve this by 2045. 

By contrast, Reform UK has said it would scrap the 2050 target, arguing that trying to achieve it would damage the UK economy.

The government is also obliged under the Climate Change Act to publish plans about how it intends to achieve Net Zero. In 2022, the government lost a case in the High Court and was ordered to update its climate strategy, because it did not include adequate information on how Net Zero would be achieved. The government lost a similar case in May 2024. Then the High Court found the government’s plans were not sufficient to meet its obligations under the Climate Change Act.

Is the UK currently on course to achieve Net Zero?

The UK’s carbon emissions have been, for the most part, gradually falling since 1990. But independent monitors of the government’s progress are concerned that the target won’t be met.

In February 2024, the government announced the UK’s greenhouse gas emissions in 2022 were 50% lower than they had been in 1990. This is based on the UK’s ‘territorial’ emissions . Territorial emissions are used to track the UK’s progress towards meeting its Net Zero target. They include all the emissions within the UK’s borders but don’t include those produced by UK businesses abroad, and any emissions from international air travel and shipping. 

Some of the most significant progress has been in emissions from coal, which have almost completely disappeared following the closure of coal power stations in recent years.

Despite the reductions that have taken place since 1990, the government’s independent watchdog, the Climate Change Committee, said in its most recent annual report it was not confident the UK was on course to meet its targets for achieving Net Zero. It said there was a “lack of urgency” in the government’s approach and that it needed to do more to support the transition away from high carbon emitting industries, including fossil fuel production. 

It also said the government needed to provide households with more advice and support to help them reduce their energy use. 

Campaigners including Friends of the Earth and Greenpeace UK have also said the UK should do more in order to achieve Net Zero, including increasing the speed of the transition from fossil fuels to renewable sources of energy and improving energy efficiency.

Critics of the Net Zero target have argued the transition to renewable energy will damage the UK economy and make it less competitive with other countries. 

We haven’t fact checked this argument, and the economic costs and benefits of this transition will be uncertain given the variety of different factors at play. 

The Office for Budget Responsibility does warn that the costs of unmitigated climate change would be much larger than bringing emissions to Net Zero, although it also acknowledges the UK remains a small contributor to global emissions.

• By Ed Scott
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Getting to Net-Zero Emissions by 2050

Avoiding the worst impacts of climate change will require aggressive action to reduce the greenhouse gas emissions that are causing Earth to warm. A number of expert reports from the National Academies have assessed the latest in climate science, technology options, and socioeconomic dimensions related to the goal of reaching net-zero emissions by the year 2050 . This resource provides an at-a-glance look at findings and U.S. policy-relevant advice from those reports.

SCROLL DOWN TO LEARN MORE

Why Net-Zero Emissions by 2050?

Reduce impacts of climate change, meet international agreements, improve health, benefit society.

Emissions Reduction Strategies

Avoiding the worst impacts of climate change requires a portfolio of options. The primary focus should be on implementing technologies to reduce greenhouse gas emissions, particularly CO 2 , complemented by efforts to remove and reliably sequester carbon from the atmosphere and to curb emissions of other greenhouse gases.

As the first line of defense against climate change, the world is transforming its energy system from one dominated by fossil fuel combustion to one with net-zero emissions of carbon dioxide. Accelerating Decarbonization of the U.S. Energy System (2021) identifies technology goals, socioeconomic goals, and policy options and federal actions that would put the United States on a fair and equitable path to net-zero in 2050.

Technology Goals

Achieving a net-zero emissions energy system will require that the United States begin working on five technology goals:

As of 2020, U.S. electricity generation was composed of about 60% fossil fuels, 20% nuclear, and 20% hydropower and other renewables. There are many sources of energy that produce little or no CO 2  emissions, including solar, wind, geothermal, and hydropower. To meet the goal of net-zero by 2050, the United States should double the share of electricity generated by non-carbon-emitting sources to at least 75% by 2030, which will require:

• Record-setting deployment of solar and wind technologies
• Scaling back coal and some gas-fired power plants,
• Preserving operating nuclear plants and hydroelectric facilities where possible.

Reducing emissions will require that existing and planned transportation, building, and industrial infrastructure be converted to use electricity from low-carbon sources where possible.  Meeting net-zero targets by 2050 will require that by 2030 the United States:

• Aim for 50% of all new vehicle sales to be zero emissions vehicles.
• Replace 20% or more of fossil fuel furnaces with electric heat pumps in buildings.
• Require that new building construction is all electric except in the coldest climate zones.
• Begin the transition to low-carbon heat sources for industrial process that cannot be fully electrified.

Technology advances such as LED lighting and energy efficient appliances have helped high-income countries substantially reduce energy use per capita and per unit of economic output.  Efficiency gains to date, however, are not enough.  Meeting net-zero targets by 2050 will require that by 2030 the United States:

• Reduce total energy use in new buildings by 50%.
• Lower energy used for space conditioning and plug-in devices in existing buildings each year to achieve a 30% reduction by the end of the decade.
• Increase goals for industrial energy productivity (dollars of economic output per energy consumed) each year.

Achieving the transition to clean electric power generation requires development of the infrastructure to support it.  By 2030, the United States should:

• Increase overall electrical transmission capacity by approximately 40% to better distribute high quality and low-cost wind and solar power from where it is generated to where it can be used.
• Accelerate the build-out of the electric vehicle recharging network.

The nation should triple federal investment in clean energy research, development, and demonstration (RD&D) in order to provide new technology options, reduce costs for existing options, and better understand how to manage a socially-just energy transition.

Socioeconomic Goals

The transition to a carbon-neutral energy system has the potential to revitalize the U.S. economy, create 1-2 million jobs over the next decade, and address inequities in our current energy system. Policies to enable the transition to net-zero emissions should be designed to advance four critical socioeconomic goals to ensure an equitable transition:

Global demand for clean energy and climate mitigation solutions will reach trillions of dollars over the coming decades, creating an opportunity to revitalize U.S. manufacturing, construction, and commercial sectors, while providing a net increase in jobs paying higher wages than the national average.

U.S. policies should promote equitable access to the benefits of clean energy systems, including reliable and affordable energy, new training and employment opportunities, and opportunities for wealth creation. Policies for the net-zero emissions economy should also work to eliminate inequities in the current energy system that disadvantage historically marginalized and low-income populations.

There will be a need to identify and mitigate job losses and other impacts on labor sectors and communities negatively impacted by the transition of the U.S. economy to net-zero emissions. U.S. policies should promote fair access to new long-term employment opportunities and provide financial and other support to communities that might otherwise be harmed by the transition.

Recommended U.S. Policies

The following policy changes would help support the U.S. transition to a new energy system.

• Setting an official U.S. emissions budget for carbon dioxide and other greenhouse gases to support the goal of reaching net-zero emissions by 2050
• An economy-wide price on carbon , in addition to other policies focusing on particular sectors
• A new National Transition Task Force to evaluate how best to support labor sectors and communities that will be affected by the energy transition
• A new Office of Equitable Energy Transitions within the White House to establish criteria, measure, and report back on net-zero transition impacts and equity considerations
• A new independent National Transition Corporation to provide support and opportunities for displaced workers and affected communities
• A new Green Bank , capitalized initially at $30 billion and rising to $60 billion by 2030, to ensure the required capital is available for the net-zero transition and to mobilize greater private investment
• A comprehensive education and training initiative to develop the workforce required for the net-zero transition, to fuel future innovation, and to provide new high-quality jobs
• Setting national standards for clean electricity and electrification and efficiency standards for vehicles, appliances, and buildings

Reducing emissions is a primary goal, but deployment of negative emissions technologies (NETs) will also be needed.  Meeting the goal of net-zero by 2050 will likely require the removal globally of about 10 Gt/y CO 2 by 2050 and 20 Gt/y by 2100.   Negative Emissions Technologies and Reliable Sequestration: A Research Agenda (2019) assessed the costs, potential for carbon removal, and barriers to overcome for several available and emerging technologies.

Assessed Potential and Limiting Factors of NET Technologies

CLICK ON A CIRCLE TO LEARN MORE

Terrestrial Carbon Removal and Sequestration

Afforestation/Reforestation Planting trees or facilitating natural regeneration of trees on land that has been in a nonforest use condition for some length of time.

Forest management Changes in forest management and agricultural practices that enhance soil carbon storage.

Biomass energy with Carbon Capture and Sequestration (BECCS)

The cultivation of crops which take up CO 2 as they grow and are used to produce electricity, liquid fuels, and/or heat. The CO 2 generated is captured and sequestered underground.

Carbon Mineralization

The use of reactive minerals (particularly mantle peridotite, basaltic lava, and other reactive rocks) to form chemical bonds with CO 2 .

Coastal Blue Carbon

Practices that increase the amount of carbon stored in living plants or sediments in tidal marshlands, mangroves, seagrass beds, and other tidal or salt-water wetlands.

Direct Air Capture

Filtering processes that capture CO 2 from ambient air and sequester it underground.

View this table for details on costs, CO 2 removal rate, and limiting factors for each technology assessed.

NETs Ready to Deploy

Terrestrial carbon removal strategies and BECCS could be scaled up to capture and store substantial amounts of carbon: ~1 Gt CO 2 /yr in the United States and ~10 Gt CO 2 /yr globally. However, unprecedented rates of adoption of agricultural soil conservation practices, forestry management practices, and waste biomass capture would be needed. Practically, about half the full potential is achievable.

NETs with High Potential but High Costs and Uncertainty

Direct air capture or carbon mineralization could be revolutionary, because of the large potential capacity for CO 2 removal. The primary impediment to direct air capture is high cost.  Carbon mineralization needs to be better understood.

Recommended Research on NETs

A substantial research initiative is needed that is focused on the following goals:

• Improve existing NETs by increasing their capacity and reducing their negative impacts and costs;
• Make rapid progress on direct air capture and carbon mineralization technologies;
• Advance NET-enabling research on biofuels and CO 2 sequestration that should be undertaken anyway as part of an emissions mitigation research portfolio.

The ocean covers 70% of the Earth’s surface and provides much of the global capacity for natural carbon sequestration. It currently holds roughly 50 times as much inorganic carbon as the preindustrial atmosphere. The ocean’s natural capacity to store carbon could be enhanced with strategies that act to remove CO 2 from the atmosphere and upper ocean and store it in ocean reservoirs, such as marine plants and geologic, or geological reservoirs for some period of time. A Research Strategy for Ocean-Based Carbon Dioxide Removal and Sequestration (2021) develops a research agenda to assess the benefits, risks, and potential for responsible scale up of six specific ecosystem-based and technological ocean-based CDR approaches.

Ocean-based Carbon Dioxide Removal (CDR) Strategies

The report assessed six carbon dioxide removal (CDR) and sequestration strategies conducted in coastal and open ocean waters. Each approach was evaluated based on its existing knowledge base, potential efficacy, durability, scale, project costs, monitoring and verification, viability and barriers, and governance and social dimensions.

View this table to compare the six ocean CDR technologies.

TABLE S.1 Comparison of the Six Ocean CDR Technologies

OCEAN-CDR RESEARCH PRIORITIES

At present, society and policymakers lack sufficient knowledge to fully evaluate ocean CDR outcomes and weigh the trade-offs with other climate response approaches, and with environmental and sustainable development goals. A research program should be implemented to address current knowledge gaps. The best approach will involve a diversified research investment strategy that includes both cross-cutting, common components and coordination across multiple individual CDR approaches in parallel.

Amongst the biotic approaches , research on ocean iron fertilization and seaweed cultivation offer the greatest opportunities for evaluating the viability of possible biotic ocean CDR approaches; research on the potential CO 2 removal and sequestration permanence for ecosystem recovery would also be beneficial in the context of ongoing marine conservation efforts.

Amongst the abiotic approaches , research on ocean alkalinity enhancement , including electrochemical alkalinity enhancement, have priority over electrochemical approaches that only seek to achieve carbon dioxide removal from seawater (also known as carbon dioxide stripping).

Cross-Cutting Research Priorities

Research Needed to Advance Ocean CDR Approaches

While reducing carbon dioxide emissions is a primary goal, much can be done to reduce other greenhouse gases that contribute to climate change. Methane, nitrous oxide, and some industrial gases (e.g., hydrofluorocarbons) comprise about 18 percent of U.S. greenhouse gas emissions in terms of CO 2 equivalents.

Sources of Methane Human activities that emit methane (the primary component of natural gas) include petroleum and natural gas systems, cattle and manure management, landfills, and coal mines. Levels of atmospheric methane have risen steadily over the past century and are unprecedented over the past 2,000 years as measured in ice cores. Methane is second only to carbon dioxide in its contribution to rising global average temperatures. Sources of Nitrous Oxide Human activities that emit nitrous oxide are primarily from agriculture and also from fossil fuel combustion, and industrial processing. Levels of nitrous oxide in the atmosphere have risen steadily since the Industrial Revolution and more sharply over the past four decades.

Reducing and Tracking Methane Emissions

Methane is not as long-lived in the atmosphere as carbon dioxide, but it is a more powerful warming agent.  Reducing methane emissions could help prevent the worst impacts of climate change.  Efforts to reduce methane emissions, along with reductions in black carbon emissions, could help reduce global mean warming in the near term, with additional benefits for air quality and agricultural productivity.

Tracking atmospheric methane levels and methane emissions is essential for informing efforts to reduce it.  However, tracking is difficult given the many human and natural sources of methane.   Improving Characterization of Anthropogenic Methane Emissions in the United States  (2018) recommends strengthening measurement, monitoring, and inventories of methane emissions and launching a nationwide research effort to address knowledge gaps.

Reducing Emissions from Agriculture

Agriculture is a large source of non-CO 2  greenhouse gases. Livestock farming may be responsible for as much as 14.5 percent of all human-induced greenhouse gas emissions (including CO 2 ).  Methane is produced when livestock digest their food and also is emitted in large quantities from rice paddies.  Nitrous oxide arises from applications of fertilizer. 

Environmental Engineering for the 21st Century: Addressing Grand Challenges (2020) identifies several pathways to reducing agricultural emissions, including:

• Feeding livestock easier-to-digest foods and strategically managing livestock waste through proper storage, reuse as fertilizer, and recovery of methane
• Precision agriculture techniques to help farmers minimize fertilizer use and reduce nitrous oxide emissions. 
• Shifting dietary patterns to de-emphasize animal-based protein, particularly beef.
• Reducing food waste, which is currently estimated at one-third of all food produced.

Evidence of Climate Change

It is now more certain than ever, based on many lines of evidence, that humans are changing Earth’s climate. Climate Change: Evidence and Causes (updated 2020), a booklet produced by the National Academies and The Royal Society, lays out the evidence that human activities, especially the burning of fossil fuels, are responsible for much of the warming and related changes observed around the world.  The booklet includes a section on Basics of Climate Change for those who want to learn more.

Earth’s Average Surface Temperatures are Increasing

Since 1900, Earth’s average surface air temperature has increased by about 1 °C (1.8 °F), with over half of the increase occurring since the mid-1970s. A wide range of other observations such as reductions in Arctic sea ice, reduced snowpack, and ocean warming, along with indications from the natural world, such as poleward migrations of some species, provide incontrovertible evidence of planetary-scale warming.

Figure 1a: Annual Global Temperature 1850-2019 Figure 1b: Evidence that Earth's Climate is Changing

Levels of Atmospheric Greenhouse Gases are Increasing

The average concentration of atmospheric CO 2 measured at the Mauna Loa Observatory in Hawaii has risen from 316 parts per million (ppm) in 1959 (the first full year of data available) to more than 411 ppm in 2019.

Human Activities are Changing the Climate

Rigorous analysis of all data and lines of evidence shows that most of the observed global warming over the past 50 years or so cannot be explained by natural causes and instead requires a significant role for the influence of human activities.

Projected Warming Given Current Emissions

If emissions continue on their present trajectory, without either technological or regulatory abatement, then warming of 2.6 to 4.8 °C (4.7 to 8.6 °F) in addition to that which has already occurred would be expected during the 21st century.

Connect with National Academies Climate Work

Climate Crisis Demands ‘Urgent and Ambitious’ Response

The presidents of the National Academies said in an October 29, 2021 statement that COP26 presented a historic global opportunity to agree on emissions reduction targets to avoid the most intolerable impacts of climate change.

The National Academies conducts a wide range of ongoing activities related to climate change, including studies, events, roundtables, and initiatives.   To learn more, visit our Climate Resources website and subscribe to the National Academies climate email list to stay apprised of news and opportunities to participate.

Reports Referenced in this Resource:

Additional Educational Resources

Subscribe to Climate @ the National Academies to stay apprised of news and opportunities to participate.

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Biodiversity & Environment

Make Your Note

Net-Zero Emissions Target

• 27 Aug 2022
• GS Paper - 3
• Environmental Pollution & Degradation

For Prelims: Net Zero Emissions, Nationally Determined Contribution (NDC), ‘Lifestyle for Environment (LIFE), Green Climate Fund (GCF), India Cooling Action Plan (ICAP), Bureau of Energy Efficiency (BEE), Efficiency Services Limited (EESL), Compensatory Afforestation Management and Planning Authority (CAMPA), Hydrogen Energy Mission.

For Mains: Essential Steps taken by India to Achieve Net-Zero Emission Target.

Why in News?

According to the report by Getting India to Net Zero , India needs a massive USD 10.1 trillion investment from now on if India is to achieve its net-zero emissions target by 2070.

What are the Key Highlights of the Report?

• The investment required by India would be USD 13.5 trillion if the net zero emission target is to be met by 2050.
• India’s Nationally Determined Contribution (NDC) targets set in 2015 are likely to be met early within the next few years through current policies.
• India could peak in emissions as soon as 2030.
• Achieving net zero by 2070 would increase annual GDP by up to 4.7% by 2036. and create 15 million new jobs by 2047.
• Ending new coal by 2023 and transitioning from unabated coal power by 2040, would be particularly impactful for reaching net zero emissions closer to mid-century.

What is Net-Zero Target?

• It is referred to as carbon neutrality , which does not mean that a country would bring down its emissions to zero.
• While the removal of gases from the atmosphere requires futuristic technologies such as carbon capture and storage.
• More than 70 countries have promised to become Net Zero by the middle of the century i.e., by 2050.
• India has promised to cut its emissions to net zero by 2070 at the conference of parties-26(COP) summit.

What Steps Have been taken by India to Achieve Net- Zero Emissions by 2070?

• India’s renewable energy targets have steadily become more ambitious, from 175 GW by 2022 declared at Paris, to 450 GW by 2030 at the UN Climate Summit , and now 500 GW by 2030 , announced at COP26.
• India has also announced the target of 50% installed power generation capacity from non-fossil energy sources by 2030, raising the existing target of 40%, which has already been almost achieved.
• To put forward and further propagate a healthy and sustainable way of living based on traditions and values of conservation and moderation, including through a mass movement for ‘LIFE’– ‘Lifestyle for Environment’ as a key to combating climate change.
• To adopt a climate-friendly and cleaner path than the one followed hitherto by others at the corresponding level of economic development.
• To reduce the Emissions Intensity of its GDP by 45% by 2030, from the 2005 level.
• With the help of the transfer of technology and low-cost international finance including from the Green Climate Fund (GCF).
• To create an additional carbon sink of 2.5 to 3 billion tonnes of CO 2 equivalent through additional forest and tree cover by 2030.
• To better adapt to climate change by enhancing investments in development programmes in sectors vulnerable to climate change, particularly agriculture, water resources, the Himalayan region, coastal regions, and health, and disaster management.
• To mobilize domestic and new & additional funds from developed countries to implement the above mitigation and adaptation actions in view of the resource required and the resource gap.
• To build capacities, and create a domestic framework and international architecture for quick diffusion of cutting-edge climate technology in India and for joint collaborative R&D for such future technologies.
• Irrespective of whether it achieves the 175 GW capacity by 2022 or the 450 GW target by 2030,
• The Bureau of Energy Efficiency (BEE) and Energy Efficiency Services Limited (EESL) has taken a number of initiatives under the National Mission for Enhanced Energy Efficiency (NMEEE) to combat climate change.
• The Compensatory Afforestation Management and Planning Authority (CAMPA) Fund created under the Compensatory Afforestation Fund Act, 2016, has thousands of crores which will hopefully be utilised soon to compensate for deforestation and restore the green cover comprising native species of trees.
• India has also announced a Hydrogen Energy Mission for grey and green hydrogen.

Way Forward

• However, they fit a general pattern of incremental progress on climate action at the global level that lacks the collective sense of urgency required to limit global warming to 1.5 degrees Celsius below pre-industrial levels.
• Further, whether India and the world can go with limited short-term emissions reduction and ambitious long-term climate action plans is something that remains to be seen.

UPSC Civil Services Examination Previous Year Question (PYQ)

Q. The term ‘Intended Nationally Determined Contributions’ is sometimes seen in the news in the context of (2016)

(a) pledges made by the European countries to rehabilitate refugees from the war-affected Middle East

(b) plan of action outlined by the countries of the world to combat climate change

(c) capital contributed by the member countries in the establishment of the Asian Infrastructure Investment Bank

(d) plan of action outlined by the countries of the world regarding Sustainable Development Goals

• Intended Nationally Determined Contributions is the term used under the UNFCCC for reductions in greenhouse gas emissions in all countries that signed the Paris Agreement.
• At COP 21 countries across the globe publicly outlined the actions they intended to take under the international agreement. The contributions are in the direction to achieve the long-term goal of the Paris Agreement; “to hold the increase in global average temperature to well below 2°C to pursue efforts to limit the increase to 1.5°C, and to achieve net zero emissions in the second half of this century.” Therefore, option (b) is the correct answer.

Q. Describe the major outcomes of the 26 th session of the Conference of the Parties (COP) to the United Nations Framework Convention on Climate Change (UNFCCC). What are the commitments made by India in this conference?  (2021)

Towards net zero emissions without compromising agricultural sustainability: What is achievable?

• Khalil, M. I.
• Osborne, B. A.
• Wingler, A.

Net-zero Germany: Chances and challenges on the path to climate neutrality by 2045

To preserve a livable planet for ourselves, for our children, and for future generations, we need to successfully navigate the transformation to a climate-neutral world within the next 25 years. This transformation to a sustainable society is a joint, global challenge and an imperative for policy makers, the business community, and each and every one of us.

Our research shows that we can do it in a socially balanced way and—viewed over the full period and across all sectors—at net-zero cost, 1 That is, the additional investments required are offset by savings in operating costs in subsequent years—when aggregated across all sectors. provided we take decisive action now. The stakes are high: failure to reach the climate targets would mean exposure to significantly higher climate risks, and a “disorderly” transition to net zero would entail significantly higher socioeconomic costs than an orderly one. The next ten years will be crucial.

After setting bold climate targets last year (a reduction in emissions by 55 percent below 1990 levels by 2030, and climate neutrality by 2050), in July the EU Commission proposed its first major package of measures to achieve this goal: “Fit for 55.” Before it recessed for the summer, the German Bundestag—following a watershed ruling by the Federal Constitutional Court—passed a new edition of the Climate Protection Act, which sets out the national goal of reaching climate neutrality by 2045. As a milestone on the way to the final goal, greenhouse-gas emissions are to be reduced by at least 65 percent by 2030 compared with 1990 levels.

As a major European economy with a large share of industry, reaching climate neutrality is a daunting endeavor for Germany (Exhibit 1). Achieving the net-zero goal requires achieving a complex technological and societal transformation on an ambitious time line: value chains have to be restructured, the power-sector transformation has to be further accelerated, we need to transition to emissions-free mobility, and we need to build and adapt the critical infrastructure before the end of the decade. In practice, the path to climate neutrality is unlikely to be linear. This is true for Germany as well as for any other country. At times, it will be necessary to backtrack and return to the drawing board. Therefore, quick and decisive action is essential—the longer we delay, the greater the cost and severity of the additional measures that would then be necessary to still hit the net-zero target.

Compared with other countries, Germany’s starting conditions are excellent, and its net-zero transition will have an impact far beyond its borders. Even if Germany cannot accomplish the global transformation to a climate-neutral world on its own, it has to play its part and set a good example as one of the leading export-oriented economies, as well as help pioneer the required new technologies and incubate new business models.

Our research shows that on a cost-optimal pathway, the transformation to net-zero emissions can be achieved at net-zero cost for society as a whole (on aggregate over the entire period and across all sectors) and in a socially balanced way—delivering a favorable business case for Germany and a leap to a new technological age. To reach climate neutrality, it is imperative to back up Germany’s net-zero ambition with concrete and commensurate actions. Germany has to tackle key challenges and actions through 2045 in the five most emissions-intensive sectors: energy, industry, transportation, buildings, and agriculture.

Substantial investments in physical assets are needed to achieve climate neutrality in Germany by 2045. Our analyses show that the total investments in physical assets required for the transition to climate neutrality includes additional investments of €1 trillion and a redirection of investments of €5 trillion. The latter are investments that have to be made in any event to replace aging infrastructure, equipment, and buildings but would be redirected to zero-emissions assets when the time comes for the scheduled replacement of assets, for instance, favoring vehicles with electric drives rather than combustion engines. The total investment volume of €6 trillion equates to an average annual investment of roughly €240 billion through 2045 or about 7 percent of Germany’s GDP 2 Statista, GDP 2019. —of which €40 billion per year would be additional investments (or about 1 percent of GDP).

If we stay on the cost-optimal path, cumulative operating cost savings can offset the additional investments required. The reason is that investments in new technologies can lead to an array of improvements in operating costs, among them the energy cost of buildings or the fuel and maintenance costs of vehicles. What’s more, Germany would benefit from a strengthened position as an industrial hub as well as from the creation of new jobs. If the transformation is achieved successfully and in a timely way, Germany will be able to maintain and build out its technological leadership in critical export-oriented sectors and secure their contribution to domestic employment and prosperity. This concerns as much as 20 percent of jobs in Germany and up to 25 percent of GDP in energy-intensive trade-exposed sectors. At the same time, the transition would lead to structural shifts in employment, for example, from thermal-power generation to hydrogen production or from combustion-engine manufacturing to battery production. Overall, employment is expected to increase, for instance, driven by greater renovation activity and the installation of heat pumps in the building sector or the manufacture and installation of solar- and wind-power capacity (Exhibit 2).

Should Germany, however, fail to create the right framework conditions for the transformation in a timely manner, German companies could lose market share and, in turn, jobs and prosperity. Moreover, in such an event, a significant increase in costs can be expected, especially for basic needs such as energy, housing, and mobility. For instance, an insufficient expansion of solar and wind power could lead to a shortfall in clean electricity for the production of green hydrogen or the electrification of industrial processes, necessitating in turn the adoption of more costly countermeasures, such as carbon capture and storage. So the longer Germany needs to accelerate on the path to climate neutrality, the costlier and less socially balanced it will be.

The next decade is decisive

The next ten years will determine whether Germany is able to achieve the transition to climate neutrality and capture the economic opportunities it creates. Consistent and speedy implementation of the required measures has to be the top priority. The preconditions have never been better—countries and international communities are agreeing on climate goals, investors are shifting their capital into climate-conscious portfolios, companies are voluntarily committing to reducing their emissions, and a majority of citizens favor the move toward sustainability and increasingly choose to buy sustainable products. It is now time to follow up on commitments with clear actions. Renewable energy and infrastructure must be expanded faster, production and sales of electric cars rapidly ramped up, and industrial processes electrified or converted to biogas. There is plenty of green capital available; the main barrier is rather the complex realignment that is required of entire industries and supply chains.

The rate of change has to be increased threefold over the next ten years compared with the last 30—with a tenfold increase in some sectors—in order to achieve the required system transformations (Exhibit 3). A look at the energy and transportation sectors—just two examples—illustrates the scale of the task at hand; challenges of a similar magnitude also arise in all of the other sectors, as explained in the report:

• In the energy sector, which currently accounts for 32 percent of all emissions in Germany, 3 In addition to emissions from the energy, industry, transportation, buildings, and agriculture sectors, the figure includes a negligible share of emissions from waste management and other sectors of around 1 percent in 2019 (German Federal Environment Agency). the annual expansion of renewable energy has to exceed the figure for 2020 roughly threefold over the next ten years—between 15 and 20 gigawatts of capacity have to be added annually, partly because the electrification of industrial processes and mobility will lead to additional power demand. Furthermore, the grid infrastructure has to be expanded massively and at a far faster pace than is the case at present. And we need a “smarter” grid that enables, for example, ramping up charging of electric cars whenever renewable energy is in ample supply. At the same time, the ramp-up of cost-effective production and the import of green hydrogen and the corresponding infrastructure are essential to decarbonize industrial processes and to provide storage capacity for green energy.
• In transportation, which accounts for 20 percent of total emissions in Germany, 4 German Federal Environment Agency. the transition to e-mobility is in full swing. However, the share of electric vehicles in Germany has to increase from 6.7 percent of new registrations in 2020 (in addition to 6.9 percent plug-in hybrids) 5 German Federal Motor Transport Authority, passenger car sector for 2020. to roughly 60 percent of new registrations in 2030 to meet the new targets set by the European Union. That said, achieving climate neutrality by 2045 will require even more ambitious targets—our models show that, by 2030, more than three-quarters of new vehicles registered annually will have to be electric—roughly a tenfold increase on 2020 registration numbers. 6 McKinsey Center for Future Mobility. The industry is making good progress: in June 2021, it had already achieved a significant year-on-year increase, with electric cars making up 12.2 percent of new registrations (in addition to 11.4 percent for plug-in hybrids). 7 German Federal Motor Transport Authority, passenger car sector for 2021. Key enablers and drivers for the required massive shift include the (climate-neutral) construction of battery plants and a huge expansion of charging infrastructure.

To master the transformation, ten core actions will be decisive

• massively accelerate the expansion of renewable energy generation
• expand the energy grid (~25 percent expansion of the power-transmission grid) and increase its flexibility
• decarbonize the basic materials industry through innovations in processes and production technology
• drive the accelerated build-out of cleantech enablers: hydrogen production and transportation, battery plants, charging infrastructure, and recycling
• transition to 100 percent zero-emissions mobility
• Improve resource productivity by establishing smart and shared mobility
• modernize the heating systems of building stock (more than 50 percent heat pumps)
• develop promising key technologies for resilient and sustainable agriculture
• accelerate the trend toward healthy eating and sustainable consumer behavior
• finance and support the net-zero transformation by developing a green portfolio

In addition to these core initiatives, a number of important enablers and framework elements will be required, such as the streamlining of permitting procedures, especially for the expansion of solar and wind power and the designation of areas for urgently needed additional infrastructure, as well as the accelerated education and training of decarbonization experts in the various sectors. This is imperative to drive implementation across the board and at all levels, from entrepreneurs and decision makers to skilled workers and trainees, all of whom have a role to play. Furthermore, all these measures are dependent on bold and committed decision makers and broad citizen support.

As engines of innovation and industrialization, companies in Germany have a pivotal role to play in developing, testing, and scaling green technologies. Many German companies have already set out on the path to net zero—defined sustainability strategies, identified ways to decarbonize, and examined their portfolios, production operations, and supply chains to find opportunities to align with the net-zero transition. Many companies are well along the transformation process, but the challenge is complex: they need to invest in transforming their facilities and their value chains end to end, identify the demands on their workforce, and prepare for the transformation, a task of enormous proportions. Germany’s automotive industry is setting a good example. All OEMs have set themselves ambitious targets, with some manufacturers aiming to build net-zero electric vehicles as early as 2030. In doing so, they have set in motion the transformation of entire value chains toward the adoption of sustainable technologies.

At the same time, the green transformation offers companies the opportunity to capture future markets. A sustainable product portfolio and technological innovations offer new growth opportunities. This is true in both the consumer-goods industry, where sustainable products deliver both significantly higher growth and significantly wider margins, and in the capital-goods sector, where players are looking ahead to a period of growth fueled by the accelerated expansion of infrastructure and the restructuring of value chains. Leading sustainability oriented companies often benefit from attractive valuations that are otherwise only reached by technology companies (with some reaching EBITDA multiples of between 15 and 30). This makes it easier for them to raise capital to invest in further green growth and to scale faster. Government stimulus packages and a growing “green capital market” are providing additional tailwinds. The key to business success lies in quickly recognizing the opportunities inherent in the transformation process and capturing the value and growth potential. In parallel, legislators have to establish the framework conditions to enable and drive a rapid transformation. Germany is currently in a good position: many of the fundamental political, technological, and financial parameters are already in place. Further concrete actions now have to be taken in the individual sectors, and the conditions created that will catalyze the required system changes. To this end, enabling reliable planning is critical—how much renewable energy will be available, when, and at what cost? Significantly accelerating the pace of change is no small challenge for policy makers and businesses. Nevertheless, it is a challenge that must be mastered if the transformation is to be achieved.

Germany’s transformation to a climate-neutral society requires enormous efforts, investments, and behavioral changes from politics, business, and also from citizens. The decade ahead is crucial: the technologies for decarbonization that are already available must be implemented at scale and speed in all sectors. But we also need to develop and scale further innovations in technologies, processes, and materials to achieve the decarbonization goals. The transformation path will be complex and extremely challenging. But it also offers significant benefits, and—for the sake of our children and future generations—failure is not an option.

The authors wish to thank Marie Rebmann and Vera Schulhof for their contributions to this article.

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