The global average temperature in 2026 is "virtually certain" to exceed 1.5°C above pre-industrial levels, a key Paris climate agreement target, the EU's earth-monitoring programme Copernicus said today.
"Virtually certain" means a probability of over 99pc, according to the statistical model Copernicus uses.
It predicts a range of 1.56°C-1.61°C for 2026. The Paris agreement seeks to curb the global rise in temperature to "well below" 2°C above the pre-industrial average, and pursues a 1.5°C limit.
This year is "most likely" to be the second-warmest on record, although there is around a 20pc chance that it will equal or surpass 2024, currently the hottest year recorded. The four-year average for 2023-26 is also expected to exceed 1.5°C above pre-industrial levels.
The forecast follows the warmest October on record globally. The average surface air temperature reached 15.35°C last month, 0.90°C above the 1991-2020 average and 1.75°C above the estimated pre-industrial level, Copernicus data show. October also marked the third consecutive month with an average temperature above the 1.5°C threshold.
El Nino conditions continued to intensify in October and sea surface temperatures "remained exceptionally high", Copernicus said. The average sea surface temperature for non-polar oceans in October broke the previous record set in 2023, reaching 20.95°C. The monthly sea surface temperature anomaly in the tropical Pacific reached 3.21°C last month, an "all-time high… exceeding the peaks recorded during previous very strong El Nino events", Copernicus said.
El Nino, a naturally-occurring weather pattern, typically leads to higher global temperatures. Its effects — and those of its opposite pattern, La Nina — vary across regions, but can significantly shift rainfall and temperature patterns.
"An exceptionally strong El Nino is adding further heat to a climate already warmed by human activities," Copernicus strategic lead for climate Samantha Burgess said.
UK weather agency the Met Office today forecast "an unusually large rise" in atmospheric CO2 for 2027. The strong El Nino "amplifies the human-driven rise by weakening natural carbon sinks", the agency said.
The annual average CO2 concentration is projected to rise by around 3.51 parts per million (ppm) in 2027, with a margin of uncertainty of 0.52ppm either higher or lower, the Met Office found.
This is the largest annual increase the agency has forecast, and is close to the record observed increase of 3.57ppm in 2024, "boosted by exceptional wildfire emissions", the Met Office said.
