The United Nations warned that the amount of heat trapped by the Earth reached record levels in 2025, marking the continuation of an alarming warming trend. The past eleven years, from 2015 to 2025, are now the hottest ever recorded, with 2025 ranking among the top three warmest years at about 1.43 degrees Celsius above the 1850 to 1900 average. United Nations Secretary-General Antonio Guterres said every major climate indicator is now 'flashing red', calling the situation a global emergency.

For the first time, the World Meteorological Organization reported on the planet’s energy imbalance, which measures the difference between energy entering and leaving the Earth. Rising concentrations of greenhouse gases such as carbon dioxide, methane and nitrous oxide have driven this imbalance to its highest level since records began in 1960. More than 91 percent of the excess heat is being absorbed by the oceans, where warming has accelerated sharply in the past two decades.

Ocean heat content reached a new record in 2025, contributing to stronger storms, marine ecosystem damage, biodiversity loss and faster melting of sea ice. The Antarctic and Greenland ice sheets continue to lose mass, Arctic sea ice remains near record lows, and global sea levels have risen about 11 centimetres since satellite measurements began in 1993. Scientists warn that ocean warming and sea level rise will continue for centuries.

Despite the temporary cooling influence of La Nina, experts caution that a return of El Nino could push temperatures even higher in the coming years. Officials described the outlook as dire, urging urgent action and warning that continued reliance on fossil fuels is intensifying climate instability and global insecurity.