Earth's energy imbalance has doubled over the past two decades, scientists report

An international group of climate scientists reported that Earth's energy imbalance has roughly doubled in recent decades, reaching record levels. The imbalance refers to the growing gap between the energy the planet absorbs and the energy it radiates back into space, a value that would be near zero under natural conditions without human influence, according to the annual "State of the Global Climate System" report. The imbalance has increased beyond projections since the 1970s, the researchers said. Scientists said roughly 90% of the excess energy is absorbed by the oceans, driving higher water temperatures, accelerated melting of polar ice sheets and glaciers, and the thawing of permafrost. Global mean sea level has risen about 23 centimeters since 1901, with the average annual rate climbing from 1.7 millimeters during 1901–2018 to above 3.6 millimeters during 2006–2025, the report found. Marine heatwaves in the oceans have become about three times more frequent since the early 1990s, averaging 65 days per year in 2025 — roughly one in every five days. Researchers warned that ocean heat buildup is intensifying extreme weather, including severe heatwaves, heavy precipitation and droughts. The report also noted that strong El Niño events in the Pacific can trigger severe droughts in Australia and heavy rainfall and flooding in other parts of the world.