Copernicus: 2026 on track to be second-hottest year as El Niño turns up the heat

The planet just logged its hottest October ever, and Copernicus Climate Change Service says the year is now nearly locked in as the second-warmest on record. Global surface air temperatures last month ran 1.75C above pre-industrial levels, the 1850-1900 baseline. It was the third consecutive month to blow past the 1.5C mark.

The EU monitor's monthly bulletin puts a 20% chance on 2026 tying or beating 2024 as the warmest year ever measured. Copernicus calls it virtually certain that temperatures will exceed 1.5C above pre-industrial levels this year. The four-year stretch from 2023 through 2026 is also expected to average above 1.5C — the threshold the Paris Agreement set to head off the worst climate impacts.

El Niño is doing the heavy lifting. Forecasters have warned for months that this one could become the strongest ever observed, and Copernicus says it set an all-time temperature record in a key Pacific zone last month. The natural warming phase, expected to peak later in the year, lifts tropical Pacific sea temperatures and reshapes weather worldwide. Forecasters say it could help push 2027 to the hottest year on record.

Samantha Burgess, strategic lead for climate at ECMWF, which runs Copernicus, said October continued a run of remarkable global warmth in both air and surface ocean temperatures. She said an exceptionally strong El Niño is adding heat to a climate already warmed by human activity.

The bulletin drops days before nations gather Monday for the UN's two-week COP31 summit in Turkey. The year leading up to it brought deadly floods in Nepal, blistering European heatwaves and major wildfires in Indonesia. In September, the United Nations declared the long-term 1.5C target would be missed within a matter of years.

Scientists say slashing greenhouse gas emissions from fossil fuels is the key to shortening any overshoot above 1.5C and dragging temperatures back down fast. Nations agreed in Paris in 2015 to hold warming well below 2C while pursuing efforts to cap it at 1.5C.