ASTANA – The world can no longer prevent warming from exceeding 1.5 degrees Celsius above pre-industrial levels, but deep emissions cuts could still limit the overshoot and bring temperatures back by 2100, according to the United Nations Environment Programme’s (UNEP) Emissions Gap Report 2026 released Oct.
21. UNEP says the chance of limiting warming to 1.5 degrees Celsius with “no or limited” overshoot, meaning less than 0.1 degrees Celsius, has been lost. It now measures progress against a “lowest possible” overshoot scenario that assumes stringent action from 2025.
Under it, peak warming stays at 1.7-1.8 degrees Celsius with a 66% chance, and temperatures return to or below 1.5 degrees Celsius by 2100 with around a 50% chance. That path requires global emissions to fall 18% by 2030, 45% by 2035 and 69% by 2040 from 2025 levels, an average of 5.7% a year.
It also depends on removing roughly 320 gigatons of CO2 from the atmosphere this century, which UNEP says is uncertain to achieve. New national pledges would cut emissions only 5-8% by 2030 and 11-15% by 2035. “Overshoot is not surrender. We can still keep it as small and as short as possible and bring temperatures back below 1.5 degrees by the end of the century,” UN Secretary-General António Guterres said in a message on the report.
“The new Emissions Gap Report from the United Nations Environment Programme shows us what it will take: cutting global greenhouse gas emissions by 18% by 2030 and 45% by 2035, compared with 2025 levels,” he said. If current policies remain unchanged, global temperatures could rise by 2.8 degrees Celsius this century and continue climbing, the report warned.
Even if countries fully implement their national climate commitments, known as nationally determined contributions (NDCs), under the Paris Agreement and sustain similar efforts, warming is projected to reach 2.6 degrees Celsius. Both estimates are higher than last year’s projections, largely because of the U.S.
withdrawal from the Paris Agreement and updated calculations of historical emissions. The report found that new climate commitments submitted since its previous assessment have done little to improve the outlook. “Every additional fraction of a degree and additional year of warming above 1.5 degrees Celsius increases climate impacts and risks, such as the deadly floods, heatwaves and wildfires that have plagued many nations this year,” said UNEP Executive Director Inger Andersen.
“So, we must pull out all the stops to minimize peak warming and return to 1.5 degrees Celsius by the end of the century. This is possible,” she added.