The years from 2015 to 2025 were the hottest on record and meteorologists are warning that the Earth’s climate is “more out of balance than at any time in observed history”.
UN Secretary-General António Guterres said the findings showed the global climate was in a state of emergency.
“Planet Earth is being pushed beyond its limits,” he said. “Every key climate indicator is flashing red.”
The World Meteorological Organization (WMO) State of Climate report, released overnight, says the planet’s energy imbalance is the highest in 65 years of record-keeping.
It says the ocean has been absorbing about 18 times the annual human energy use each year for the past two decades
This has been coupled with increased extreme weather events.
“The Earth’s climate is more out of balance than at any time in observed history, as greenhouse gas concentrations drive continued warming of the atmosphere and ocean and melting of ice,” the report said.
“These rapid and large-scale changes have occurred within a few decades but will have harmful repercussions for hundreds – and potentially thousands – of years.”
The report says 2015-2025 were the hottest 11 years on record, and 2025 was the second or third hottest year on record, at about 1.43 °C above the 1850-1900 average.
It says the ocean continues to warm and absorb carbon dioxide each year for the past two decades the extent of sea ice in the Arctic is at or near record lows. Glacial melt was “continuing unabated”.
Mr Guterres said humanity had just endured the 11 hottest years on record.
“When history repeats itself 11 times, it is no longer a coincidence,” he said. “It is a call to act.”
The Earth’s energy balance measures the rate at which energy enters and leaves the Earth system. Under a stable climate, incoming energy from the sun is about the same as the amount of outgoing energy.
However, increasing concentrations of heat-trapping greenhouse gases – carbon dioxide, methane and nitrous oxide – to their highest level in at least 800,000 years have upset this equilibrium, the report says.
“Scientific advances have improved our understanding of the Earth’s energy imbalance and of the reality facing our planet and our climate right now,” WMO Secretary-General Celeste Saulo said.
“Human activities are increasingly disrupting the natural equilibrium and we will live with these consequences for hundreds and thousands of years.
“On a day-to-day basis, our weather has become more extreme. In 2025, heatwaves, wildfires, drought, tropical cyclones, storms and flooding caused thousands of deaths, impacted millions of people and caused billions in economic losses.”
The State of the Global Climate report 2025 is based on scientific contributions from National Meteorological and Hydrological Services, WMO Regional Climate Centres, United Nations partners and dozens of experts.
The following are the highlights of the report.
Global average near-surface temperature
The past 11 years, 2015–2025, were the 11 warmest years on record. 2025 was the second or third warmest year (depending on the dataset) in the 176-year observational record.
Ocean heat content
In 2025, ocean heat content (to a depth of 2000 metres) reached the highest level since the start of records in 1960, exceeding the previous high set in 2024. Over the past nine years, each year has set a new record for ocean heat content. The rate of ocean warming over the past two decades,
Global average sea level
In 2025, global mean sea level was comparable to the record-high levels observed in 2024. It was around 11cm higher than at the start of the satellite altimetry record in 1993. The year-to-year increase from 2024 to 2025 was smaller than 2023 to 2024, consistent with short-term variability associated with La Niña conditions.
Glacier mass balance
In the 2024-2025 hydrological year, glacier mass loss from reference glaciers was among the five worst on record. This continues a trend of accelerated glacier mass loss since records started in 1950, with eight of the 10 years with the largest glacier ice loss occurring since 2016. In 2025, exceptional levels of glacier mass loss occurred in Iceland and along the Pacific coast of North America.
Sea-ice extent
The annual average Arctic sea-ice extent for 2025 was the lowest or second lowest on record in the satellite era (1979), and the average Antarctic sea-ice extent for 2025 was the third lowest after 2023 and 2024.
The full report is here
