Earth is accumulating heat in its systems at an accelerating rate, according to a report from the UN weather agency released as the Cop31 climate change summit begins in Turkey. The World Meteorological Organization (WMO) stated in its State of the Global Climate update that the imbalance between incoming solar energy and outgoing energy has reached a record high.
Rising Temperatures and Ocean Impact
The WMO reported that the average global surface temperature between January and September 2026 reached approximately 1.47C above pre-industrial levels. Sea surface temperatures achieved monthly records, and sea levels climbed to their highest point since monitoring began. Because oceans absorb 90% of excess greenhouse gas heat, 2026 is on track to mark a tenth consecutive year of record ocean heat.
António Guterres, the UN secretary general, stated that the planet has entered a new era of climate extremes. He noted that a supersized El Niño is colliding with a world already superheated by human-induced climate change, causing climate records to fall continually and increasing human costs for those least responsible.
Diplomats and world leaders gathered in Antalya for the 31st conference of the parties to the UN framework convention on climate change. The WMO noted that atmospheric carbon dioxide concentrations reached 426.8 ppm in 2025, up from 356.42 ppm when the convention was signed in 1992, representing a 53% increase since the onset of the Industrial Revolution in 1750.
Accelerating Energy Imbalance
Data on ocean heat content indicates that Earth’s energy imbalance increased at a rate of 0.3W per square metre each decade from 2001 to 2025, compared with 0.13W per square metre between 1960 and 2025. Consequently, 2026 remains on track to rank among the four warmest years on record globally, making the period from 2023 to 2026 the four warmest years in observational history.
The year began under La Niña conditions in the Pacific, which typically lower average global temperatures by 0.1C to 0.2C. However, a developing El Niño—forecast to be stronger than any observed in the past 1,000 years—suggests the final mean temperature for 2026 will likely exceed 1.47C above pre-industrial averages. Heat within the upper 2,000 metres of the ocean reached record highs in 2025, with warming trends projected to continue on timescales lasting centuries or millennia.
At the polar regions, Antarctic sea ice reached its third-lowest annual maximum in 2026, while Arctic maximum levels recorded their lowest or second-lowest extent. Glaciers globally lost more than 400 gigatonnes of mass, marking the fourth consecutive year that all 19 glacierized regions experienced mass loss.
Bill McGuire, a professor emeritus of geophysical and climate hazards at University College London, stated that the findings contained no surprises regarding global temperature, sea level rise, and sea ice extent. He highlighted the growing imbalance between incoming and outgoing energy, driven by rising greenhouse gas concentrations that trap increasing amounts of heat.
He added that this energy imbalance more accurately tracks global heating and future warming rates than emissions alone, as natural feedbacks accelerate temperature increases. Recent research cited by McGuire suggests the permanent 1.5C threshold could be crossed in 2028, with warming rates reaching 0.4C per decade and potentially surpassing 2C in the late 2030s.
