UN Climate Change synthesised 127 new national pledges covering 71 per cent of global emissions and found they would cut output 6 per cent below 2019 levels by 2035. The same morning the WMO put atmospheric carbon dioxide at a record 426.8 parts per million.
Researchers at Imperial College London and the London School of Hygiene and Tropical Medicine modelled heat-related mortality across 854 European cities for June to August 2026 and found the highest total the method has produced for any European summer, with roughly two-thirds of the deaths attributed to fossil fuel warming.
The IPCC ended a week in Addis Ababa without agreeing when the three Seventh Assessment Report volumes will appear or how to fund them. The split is between delivery in 2028, before the next Global Stocktake, and pushing two reports into 2029.
A joint Franco-German position published on 16 October 2026 would let new petrol and diesel cars stay on sale in the EU after 2035 by cutting the fleet target to 90 per cent and removing the obligation to offset the rest, in exchange for stricter Made in Europe rules on subsidies and public contracts.
California's corporate greenhouse gas reporting regulation cleared its final administrative hurdle on 12 October 2026. Companies with more than $1 billion in revenue that do business in the state now have under a month to file, under enforcement terms that let some of them file nothing at all.
WMO's Global Seasonal Climate Update, published on 8 October 2026, puts the probability that El Niño persists through February 2027 at near 100 per cent. NOAA reported the following day that global sea surface temperature departures in September had reached an all-time high for any month.
A study in Earth's Future finds that 75 per cent of tropical forests endured simultaneous extreme heat and drought for an average of six months during the 2023-24 El Nino, and projects those conditions as the annual norm in most tropical regions by 2043 under any scenario short of carbon neutrality by 2075. A companion paper in Communications Earth & Environment estimates that fire-derived ozone adds carbon losses equal to 24 per cent of the fires' direct emissions.
Argument in No. 25-170 began at 10:06 a.m. on 5 October 2026. The court must decide whether federal law precludes state-law damages claims over greenhouse-gas emissions, and whether it has jurisdiction to rule at all. Nearly 60 similar suits are pending.
Twenty-one states, the District of Columbia and three cities filed a petition for review on 1 October 2026 against the EPA's September repeal of greenhouse gas limits for coal- and gas-fired power plants, arguing the agency never calculated the full cost of the rescission.