The world will no longer be able to keep global warming below 1.5°C and must now focus efforts on limiting how far this threshold will be exceeded, the United Nations said ahead of COP31 climate negotiations, which will take place next month in Turkey. The withdrawal of the United States from the fight against climate change is making this task even harder.
Countries will need to cut carbon dioxide (CO₂) emissions by almost a fifth by the end of the decade, compared with 2025 levels, to achieve the smallest possible overshoot of that limit, according to the United Nations Environment Programme (UNEP) in its annual Emissions Gap Report published on Wednesday.
UNEP defined this scenario as one in which global temperatures sit between 1.7°C and 1.8°C above pre-industrial levels and return to 1.5°C by the end of the century. The agency described the necessary cuts in emissions as “immediate, deep, rapid, and sustained.”
Less than half of the G20 economies are on track to meet their current 2030 targets, according to the report, which projects warming of 2.6°C by 2100 under current policies.
“Now is not the time to throw in the towel,” said UNEP Executive Director Inger Andersen to reporters. “On the contrary, it is about finding the way back.”
The report outlines possible pathways after the UN said last month that surpassing the 1.5°C limit foreseen in the Paris Agreement of 2015 is now virtually inevitable.
Each fraction of an additional degree of warming above pre-industrial levels increases the risk of extreme weather events, harms global food production, and accelerates inflation.
The withdrawal of the United States from the Paris Agreement has been particularly detrimental to global climate efforts. While the report notes that the collective growth of emissions from G20 countries slowed last year, the rise in U.S. emissions, by 133 megatons of CO₂, far surpassed that of any other country. Turkey, host of COP31, came in second, with an increase of 24.4 megatons.
A climate target announced by the United States in the last weeks of the Biden administration, which had the potential to reduce emissions by 1 gigatonne by 2030, was removed from UNEP’s calculations. One gigatonne is roughly the annual emissions of the country’s entire vehicle fleet.
Although global greenhouse gas emissions last year were close to 2024 levels, the report warns that “it is still early to conclude that global emissions have plateaued or peaked.” Emissions from fossil fuel use rose, but were offset by declines in emissions related to land use and forests.
World leaders and climate negotiators are set to meet in early November in Antalya, Turkey, for COP31, where they will discuss ways to curb warming and adapt economies to its impacts.
Although Turkey is seeking a global commitment to raise electrification to 35% of energy consumption by 2035, the ongoing war with Iran and upcoming elections in countries such as Brazil and France have reduced the political priority of the climate agenda.
COP31 negotiators also face the possibility of not having important climate science reports on the agenda after a meeting of the Intergovernmental Panel on Climate Change (IPCC), held last week in Addis Ababa, was suspended without agreement on timelines.
“The emission gap now is a leadership gap,” said UN Secretary-General António Guterres. “Surpassing the target does not mean surrender. We can still ensure that this overshoot is the smallest and most brief possible and bring temperatures back below 1.5°C before the end of the century.”
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