PETALING JAYA: Marking World Meteorological Day, the United Nations’ weather agency has declared that the planet has just experienced the hottest decade on record.
The World Meteorological Organization’s (WMO) State of the Global Climate 2025 report said the period from 2015 to 2025 ranks as the 11 hottest years ever recorded, with 2025 itself among the top three warmest years at about 1.43°C above the 1850–1900 average.
Climate scientists use the 1850–1900 period as a baseline to represent “pre-industrial” global temperatures, as it marks the earliest era with reliable and widespread instrumental records.
The report noted that extreme weather events, including intense heat, heavy rainfall and tropical cyclones, have caused widespread disruption and devastation, underscoring the vulnerability of interconnected economies and societies.
It added that the oceans continue to warm and absorb carbon dioxide, taking in energy equivalent to about 18 times annual global human energy consumption each year over the past two decades.
Sea ice levels remain near historic lows, with Arctic ice at or close to record lows and Antarctic sea ice the third lowest on record. Glacier melt has also continued unabated.
Commenting on the report, United Nations Secretary-General António Guterres warned that the global climate is in a state of emergency.
“Planet Earth is being pushed beyond its limits. Every key climate indicator is flashing red,” he said in a statement.
“Humanity has just endured the eleven hottest years on record. When history repeats itself eleven times, it is no longer a coincidence. It is a call to act,” he added.
For the first time, the report includes Earth’s energy imbalance as a key climate indicator, showing that the gap between incoming and outgoing energy has widened since records began in 1960 — reaching a new high in 2025.
Greenhouse gas concentrations, including carbon dioxide, methane and nitrous oxide, are now at their highest levels in at least 800,000 years, further disrupting the planet’s energy balance.
The report explained that under stable conditions, energy entering the Earth system from the sun is roughly equal to the energy leaving it.
WMO Secretary-General Celeste Saulo said human activities are increasingly disturbing this natural equilibrium, with consequences that will persist for centuries.
“On a day-to-day basis, our weather has become more extreme. In 2025, heatwaves, wildfires, droughts, tropical cyclones, storms and flooding caused thousands of deaths, affected millions of people and resulted in billions of dollars in economic losses,” she said.
The report also highlighted how excess heat is distributed within the Earth system: more than 91% is stored in the oceans, about 5% in land masses, and around 3% contributes to ice melt.
Ocean heat content reached a record high in 2025, with the rate of warming more than doubling between 2005 and 2025 compared with 1960 to 2005.
Meanwhile, ice sheets in Antarctica and Greenland continue to lose mass, while Arctic sea ice in 2025 ranked as the lowest or second lowest in the satellite record. Exceptional glacier loss was also recorded in Iceland and along the Pacific coast of North America.
