The past ten years (2015–2025) have been the hottest on record. Warming oceans, melting ice, and extreme weather have affected millions of people, economies, and ecosystems around the world’s said in its State of the Global Climate 2025 report.
According to the report, 2025 was the second or third warmest year on record, with temperatures about 1.43°C above the 1850–1900 average.
2024 was the warmest
In the 176-year record, 2025 was the second or third warmest year (depending on the dataset), partly due to a shift to La Niña conditions, which briefly cool the planet. The average global temperature was about 1.43 ± 0.13°C above the 1850–1900 pre-industrial level.
The year 2024, which started with a strong El Niño, is still the warmest year on record, with temperatures about 1.55°C higher than the average from 1850 to 1900.
The ocean continues to warm and absorb carbon dioxide. For the past 20 years, it has absorbed energy nearly eighteen times the annual human energy use each year.
Near record lows
The report said Arctic sea ice was at or near record lows, Antarctic sea ice was the third lowest on record, and glaciers continued melting without slowing down.
“The State of the Global Climate is in a state of emergency. Planet Earth is being pushed beyond its limits. Every key climate indicator is flashing red,” said UN Secretary-General António Guterres.
The WMO released its State of the Global Climate report on Monday to commemorate World Meteorological Day on March 23.
Energy imbalance
The report listed Earth’s energy imbalance as a key climate indicator for the first time.
The earth’s energy balance shows how much energy enters and leaves the earth. In a climate that doesn’t change much, the energy that comes in from the sun is about the same as the energy that goes out.
But the levels of greenhouse gases that trap heat, like carbon dioxide, methane, and nitrous oxide, have reached their highest levels in at least 800,000 years, throwing this balance off.
Getting worse
The report said that the Earth’s energy imbalance has been getting worse since records began in 1960, especially in the last 20 years, and reached a new high in 2025.
“Scientific advances have improved our understanding of the Earth’s energy imbalance and of the reality facing our planet and our climate right now,” said WMO Secretary-General Celeste Saulo.
About 1% of the extra energy goes into warming the atmosphere, including the air near the Earth’s surface where people feel it. About 5 per cent of the extra energy is stored in land masses.
The ocean holds more than 91 per cent of the excess heat, which helps keep temperatures on land from rising too quickly. In 2025, ocean heat content reached a new record high, and the rate at which it warmed more than doubled between 1960 and 2005 and 2005 and 2025.
Glacier loss
Three per cent of the excess energy goes into warming and melting ice. Ice sheets in Antarctica and Greenland have lost large amounts of ice, and Arctic sea ice was among its lowest levels in 2025. Major glacier loss was also seen in Iceland and along North America’s Pacific coast.
The Intergovernmental Panel on Climate Change (IPCC) projected that the oceans will keep getting warmer and the sea levels will keep rising for hundreds of years. It will take hundreds to thousands of years for changes in ocean warming and deep ocean pH to go back to normal.
Data from monitoring stations show that the levels of the three main greenhouse gases—carbon dioxide, methane, and nitrous oxide — kept going up in 2025.
Highest CO2 levels
In 2024, carbon dioxide levels in the atmosphere were at their highest point in the last 2 million years. Methane and nitrous oxide levels were at their highest point in at least 800,000 years.
The rise in carbon dioxide (CO₂) levels in 2024 was the biggest yearly rise since measurements started in 1957. The WMO report says that this was mostly because fossil fuel emissions kept going up and the land and oceans weren’t able to absorb as much carbon.
Ocean heat content
Ocean heat content (up to 2,000 metres deep) reached its highest level since records began in 1960 in 2025. This was higher than the previous record set in 2024. The report says that every year for the past nine years has set a new record for ocean heat content.
In 2025, about 90 per cent of the ocean surface had at least one marine heatwave, even though La Niña conditions were present.
Global mean sea level
In 2025, the world’s sea levels were about 11 cm higher than they were in 1993, when satellite measurements started. They were also similar to the record highs seen in 2024.
The report said that rising sea levels hurt coastal ecosystems and let saltwater into groundwater, which makes flooding worse.
About 29 per cent of the CO₂ due to human activities between 2015 and 2024 was absorbed by the ocean. This made the ocean surface pH continue to drop.
Ocean acidification harms biodiversity, throws ecosystems off balance, and has an effect on fishery food production.
Published on February 23, 2026