Despite a possible plateau in global greenhouse-gas emissions last year, average temperatures are set to hurtle past 2 °C of warming around the middle of the century, barring a major acceleration in emissions cuts, finds the United Nations’ latest report on climate change.

“The world can no longer avoid overshooting the 1.5 °C limit, and the consequences are already devastating,” said outgoing UN secretary-general António Guterres in a press briefing announcing the report — an annual accounting of progress towards tackling climate change published by the UN Environment Programme (UNEP) on 21 October. Guterres pointed to the extended heatwaves, massive wildfires and deadly floods that have disrupted much of the world in 2026. He called for faster action from governments to cut emissions by transitioning away from fossil fuels, expanding clean electricity and reversing deforestation.

Under current policies, scientists estimate that warming will peak at 2.6 °C to 2.8 °C above pre-industrial levels this century — substantially exceeding the 2°C upper limit of the 2015 Paris Agreement targets to avoid the most dangerous consequences of climate change. There is also a smaller, 10% chance of warming exceeding 3.4 °C on the current trajectory, which researchers say would be catastrophic. Even under a scenario in which countries achieve all existing emissions pledges, the report projects 2.1 °C of warming.

Although the 1.5 °C goal to limit the worst effects of climate change is out of reach — 2026 is projected to be the second year in which temperatures have surpassed that level of warming — the report maintains that it might be possible to ‘overshoot’ that target, then bring temperatures back down through rapid decarbonization and a massive expansion of carbon dioxide removal.

UNEP’s assessment comes ahead of November’s COP31 climate summit in Antalya, Turkey, at which governments will take stock of efforts to mitigate and

adapt to climate change. “The emissions gap is now a leadership gap. And the world is running out of time and excuses to close it,” Guterres said.

Bright spots There is some good news in this year’s report. Initial estimates show that global greenhousegas emissions in 2025 were about the same or slightly lower than they were in 2024. That was mainly due to a decrease in emissions from land-use activities, particularly as a result of a quiet year for wildfires after unprecedented blazes in 2024.

That would be the first decline seen since the COVID-19 pandemic, and it could represent the start of a plateau or even a peak in emissions (see ‘Have emissions peaked?’). But researchers caution that a single year is not enough to determine whether this is a lasting shift.