The United Nations reported recently that global warming will soon exceed 1.5 degrees Celsius, the goal nations agreed to strive toward in the 2015 Paris Agreement. The best plausible outcome now is a peak near 1.8 degrees Celsius. Most projections are far worse.
Scientists have concluded that even 1.5 degrees of sustained warming brings severe consequences (including extreme storms, fires, and heat), and that above it, the risk of unmanageable, irreversible damage rises sharply. Overshooting means much larger investments will be required to prepare for now-inevitable climate disasters.
Yet this failure creates an opening. It clarifies that in the decades to come—decades that matter—not all solutions limit warming equally. Instead of trying to do everything everywhere all at once, nations need to prioritize certain things in certain places right now to limit the damage. To start with, the fastest gains are from cutting super pollutants like methane and ending tropical deforestation. And because some overshoot is now certain, protecting people from what is already coming can no longer be an afterthought.
A demonstrator holds a banner showing the 1.5 degree Celsius mark outside the Reichstag building in Berlin, Germany, on April 18. Omer Messinger/Getty Images
The global climate goal should not change. Sustained warming above 1.5 degrees Celsius could prove catastrophic. The overshoot must be temporary, with nations bringing temperatures back below 1.5 degrees within a century. Lowering temperatures will require removing carbon dioxide from the air on a vast scale through reforestation and new technologies that are only just emerging. But between now and midcentury, the priority should be different: limiting how far above 1.5 degrees temperatures go, and how long they stay there.
The height of the peak matters because parts of the climate system may fail abruptly beyond certain temperature thresholds. As warming increases, so does the risk that the West Antarctic ice sheet begins an irreversible retreat, that Atlantic circulation slows, or that the Amazon shifts from rainforest to something drier and smaller, with dire implications for deforestation emissions and food security.
How long temperatures remain above 1.5 degrees matters for a different reason. A system can survive a brief excursion above its critical threshold but fail under a sustained one. Every additional decade above 1.5 degrees is another decade of pressure on systems that may not recover.
What determines the peak is not what determines long-term temperatures. The world now has two problems to solve, not one—and the solutions that address them best are not the ones domestic policy and climate diplomacy have been built around.
For 30 years, the world has counted climate progress in tons of greenhouse gas mitigation. The accounting has treated a ton as a ton, wherever it comes from and whenever it is avoided. New priorities emerge when the goal becomes managing overshoot.
Replacing fossil fuel infrastructure is the largest and most important climate project over this century. But carbon dioxide warms slowly for a long time. Taking into account the temporary cooling effect of short-lived aerosols co-emitted when fossil fuels burn, the net cooling gains from cutting these emissions are real and essential, but back-loaded. A clean energy transition remains vital, yet it is neither sufficient nor the most urgent task.
Other climate interventions such as reducing climate super pollutants (greenhouse gases that are far more potent than carbon dioxide) and stopping deforestation do more in the near term to limit the size and duration of overshoot above 1.5 degrees. That’s because these solutions are what the nonprofit Project Drawdown calls emergency brakes—they work fast, are immediately available with existing technologies, and require no complicated (and slow) infrastructure turnover.
Methane, the largest super pollutant and a gas that disappears within roughly a decade of being released, is responsible for roughly half a degree of the warming the world has already experienced.
Coal, oil, and gas operations leak and deliberately vent enormous volumes of methane. The equipment to stop it is ordinary, available, and much of it pays for itself in gas that gets captured and sold rather than lost. Landfills and food waste are also significant methane sources with affordable solutions. None of this requires new technology or infrastructure, only regulation and enforcement.
In addition, nitrous oxide vented from the factories making nylon and fertilizer is another super pollutant, as are the hydrofluorocarbons used in refrigeration and air conditioning. Both are also unusually cheap to eliminate.
Meanwhile, clearing forests releases more than one-tenth of the world’s greenhouse gases—roughly the same as the entire United States economy. The problem is unusually concentrated: Brazil, Indonesia, and the Democratic Republic of the Congo together account for more than half of global emissions from land use. Deforestation emissions often run alongside potent methane and carbon emissions from charcoal production and newly drained soils, particularly in Indonesia’s peatlands.
Brazilian President Luiz Inácio Lula da Silva is shown during a presentation of statistics of illegal deforestation in the Amazon, seen in Brasília, Brazil, on Nov. 12, 2009.Evaristo Sa/AFP via Getty Images
Policy moves this lever fast and at scale. Unlike planting trees, which takes decades to have a major effect, sparing a forest and rewetting peatlands deliver full climate benefits immediately. Brazil cut Amazon deforestation by roughly 80 percent across President Luiz Inácio Lula da Silva’s first two terms, and sharply again after he returned to office. Indonesia cut primary forest loss by nearly two-thirds between 2015 and 2022 under President Joko Widodo, helped by stronger enforcement and a permanent moratorium on clearing primary forest and peatland. These are some of the largest climate successes in history.
Forests also do something no other fast mitigation option does: They protect people from the warming already coming. Intact natural landscapes buffer against severe storms, droughts, floods, and more. And ending deforestation cuts the risk of catastrophic collapse of these crucial carbon-rich biomes.
Gains on forests can also be reversed. Amazon deforestation in Brazil rose 60 percent under Jair Bolsonaro. But the reversal proves the point rather than undercutting it: Policy alone moves this lever at scale, in either direction. Sustained progress would shave real fractions of a degree off the temperature peak and shorten the overshoot.
So what would a new climate diplomacy look like if it were organized around speed and scale, as well as managing unavoidable harm? Here are four examples.
First, fossil fuel producers and importers can partner to cut methane, clipping 0.1 degree Celsius from peak warming, per the International Energy Agency. Oil and gas producers can require low-leak equipment, restrict or end routine flaring and venting, detect and repair leaks, and contain super-emitter accidents. Coal producers can drain methane when opening mines, destroy methane in ventilation air, and seal old mines. Importers can build on the European Union Methane Regulation to insist on these practices to access their markets. Development banks can help in poor producer countries. These measures would be roughly free, paid for by selling captured gas.
Second, the international community can create stronger financial incentives for tropical forest countries. Pay-for-performance must make a standing forest more valuable than farmland. This effort should build on past partnerships between Norway and tropical forest countries and financial mechanisms introduced by Brazil in 2023. If existing approaches don’t suffice, new revenue streams (such as taxes on fossil fuels used for international shipping or aviation) should be considered. Also, importers must adopt trade bans or carbon border taxes—the EU has done the former—on agricultural commodities produced in ways that harm forests.
Third, nations can quickly cut industrial nitrous oxide emissions to eliminate the equivalent of one-quarter of the cars on the road in the United States. Simple standards on a few dozen adipic acid facilities mainly in China could cut China’s overall greenhouse gas emissions by more than 2 percent—a substantial down payment on its 2035 Paris target that now includes non-carbon dioxide gases. Carbon markets that credit reductions beyond 90 percent can cover some of the costs and deliver deeper reductions. The EU may force the issue by covering these emissions under its Emissions Trading System and carbon border adjustment in 2030.
Fourth, because even the fastest mitigation will not prevent all of the harm now locked in, wealthy nations must help the poorest withstand inevitable climate-fueled disasters. Minimizing famines and other humanitarian tragedies and the mass migration they trigger must become central to international development efforts. This will require new capital investments in international financial institutions and new regulations to force private creditors to pause debt repayments after mega hurricanes and other climate-related disasters strike poor nations.
These solutions belong at the center of international climate cooperation. Putting them there means taking climate diplomacy somewhere it has not been.
Still, possible objections deserve answers.
One objection is that prioritizing anything means deprioritizing everything else—that a fast mitigation focus on super pollutants and forests invites delay on fossil fuels. It does not. Eliminating carbon dioxide from the energy and industrial economy remains vital for determining where warming finally settles, and every five years of delay adds roughly one-tenth of a degree to the eventual peak. The argument here is that fast levers and resilience have been badly underweighted, not that the slow ones can wait. The energy transition must be accelerated too.
The second objection is that the solution set does not include one strategy that could reduce temperatures temporarily on a planetary scale: solar radiation modification, which involves injecting reflective particles into the stratosphere to dim incoming sunlight. Doing so could reduce global warming within months. But these interventions are unprecedented and carry the risk of unintended consequences. And while they might lower temperatures, they would not stop the buildup of climate pollution or the ocean acidification it causes. Governments should substantially increase research on solar radiation modification and other climate interventions but not deploy them at this time.
The third question is about fairness rather than strategy. Most of the emission reductions discussed here are in developing countries with low per capita incomes and emissions; most of the historical responsibility and financial capacity sit elsewhere. But fast mitigation also disproportionately benefits low-income countries dangerously exposed to climate impacts. And where warming can be slowed fastest and who should pay to slow it are different questions with different answers, and the partnerships described above are built to answer the second.
From left to right, Indonesian President Joko Widodo, Canadian Prime Minister Justin Trudeau, Microsoft CEO Bill Gates, U.S. President Barack Obama, French President Francois Hollande, and Indian Prime Minister Narendra Modi pose on the opening day of the United Nations Climate Change Conference (COP21) at Le Bourget, France, on Nov. 30, 2015. Ian Langsdon/AFP via Getty Images
Missing 1.5 degrees Celsius is evidence that temperature targets alone do not motivate massive economic and social change. A global temperature goal belongs to everyone and therefore no one.
Goals set for specific gases, regions, or sectors work differently. A standing forest has an owner, a community, and an export market. Methane mitigation has an industry that, with the right policy, profits from selling gas rather than venting it. Global temperature goals promise ambitious outcomes; well-designed sectoral goals can help deliver them.
Sectoral and regional goals are also easier to negotiate and implement. A global temperature target leaves nearly 200 nations to work out their own share of the responsibility. An international effort to end tropical deforestation or capture methane from fossil fuel production could begin with a handful of nations. A few dozen plants account for most of the world’s industrial nitrous oxide. Concentration and specificity are what make these problems tractable.
Sectoral partnerships would supplement Paris, not replace it. Its system of universal targets and plans remains essential.
Well-designed sectoral initiatives have the potential to be more durable than traditional climate policy. Cutting methane from oil and gas operations means capturing a commodity and selling it. Cutting it from landfills and agriculture means cleaner air in cities where pollution kills people now. Protecting forests means securing water for downstream farms and cities, defending biodiversity, and honoring the land rights of communities who have protected those forests for generations. Helping poor nations withstand storms that drive people into poverty and onto migrant boats is both moral and self-interested. None of this requires anyone to be persuaded about climate first, and none of it is a pretext: The benefits are real and would be worth pursuing even if the climate case vanished tomorrow.
That is what the end of the 1.5 degree Celsius era makes possible. A single global number asked the world to do everything everywhere all at once, and delivered too little. Setting priorities—in the sectors and places where they count most—will deliver more. That is the new climate calculus.
