Earth's energy imbalance increased to a new high in 2025, driven by rising greenhouse gas levels. The imbalance reflects excess energy trapped by carbon dioxide, methane and nitrous oxide.
More than 91 per cent of excess heat is stored in the ocean, which reached record heat content. The rate of ocean warming more than doubled between 1960–2005 and 2005–2025.
Global sea level in 2025 was 11 centimetres above the 1993 satellite baseline. The Antarctic and Greenland ice sheets lost significant mass, and Arctic sea ice extent was at a record low.