A United Nations Environment Programme report released on Wednesday, Oct. 21, 2026, projected that global temperatures will rise to 1.7-1.8 degrees Celsius above pre-industrial levels by mid-century under the most optimistic scenario. This assessment indicates that global warming is expected to exceed previous estimates, despite the rapid expansion of renewable energy and existing climate policies.
The report arrives as nations prepare for COP31, the next round of climate talks scheduled to take place in Turkey. The revised projections reflect factors including the United States' withdrawal from the Paris Agreement and updated assessments of historical emissions. Under the 2015 Paris Agreement, nations aimed to limit the average temperature increase to well below 2 degrees Celsius, with an ideal target of 1.5 degrees.
According to the report, current policies are projected to result in a 2.8 degree Celsius increase by 2100. If existing pledges are fully implemented, that figure is estimated at 2.6 degrees. To achieve the mid-century outcome of 1.7-1.8 degrees, the UN stated that greenhouse gas emissions must fall by 18% from 2025 levels by 2030, 45% by 2035, and 69% by 2040. Current national plans are estimated to cut emissions by only 5-8% by 2030 and 11-15% by 2035.
UN Secretary-General António Guterres said it was crucial not to give up on efforts to rein in emissions fueling natural disasters such as floods and fires. He stated that even with an overshoot of targets, temperatures could potentially return to 1.5 degrees by the end of the century. The UN Environment Programme noted that climate plans submitted since last year have made virtually no difference to warming projections.
The report stated that returning to 1.5 degrees would depend on large-scale carbon removal, the feasibility of which is described as uncertain. The UN’s "lowest possible" overshoot scenario now offers roughly a 50% chance of returning temperatures to 1.5 degrees Celsius or below by the year 2100.