Adedokun Waliyu 
The amount of heat trapped by the Earth reached record levels in 2025, with the consequences of such warming feared to last for thousands of years, the UN warned Monday.
The 11 hottest years ever recorded were all between 2015 and 2025, the United Nations’ WMO weather and climate agency confirmed in its flagship State of the Global Climate annual report. Last year was the second or third hottest year on record, at about 1.43 Celsius above the 1850–1900 average.
“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 Antonio Guterres. “Humanity has just endured the 11 hottest years on record. When history repeats itself 11 times, it is no longer a coincidence. It is a call to act.”
For the first time, the WMO climate report includes the planet’s energy imbalance — the rate at which energy enters and leaves the Earth system. Under a stable climate, incoming solar energy roughly equals outgoing energy. However, rising concentrations of heat-trapping greenhouse gases — carbon dioxide, methane, and nitrous oxide — now at their highest levels in at least 800,000 years — have upset this equilibrium. The Earth’s energy imbalance reached a new high in 2025.
Ocean Heat Record
More than 91 percent of the excess heat is stored in the ocean. Ocean heat content reached a new record high in 2025, and its rate of warming more than doubled from the 1960–2005 period to the 2005–2025 period. WMO chief Celeste Saulo warned that human activities are increasingly disrupting the natural equilibrium, with consequences that will be felt for hundreds and thousands of years.
Ocean warming carries far-reaching consequences, including degradation of marine ecosystems, biodiversity loss, and reduction of the ocean’s carbon sink capacity. It also fuels tropical and subtropical storms and worsens sea-ice loss in the polar regions.
Both the Antarctic and Greenland ice sheets have lost considerable mass, and the annual average extent of Arctic sea ice in 2025 was the lowest or second-lowest ever recorded in the satellite era. Global mean sea level last year was around 11 centimetres higher than when satellite records began in 1993. Ocean warming and sea level rise are projected to continue for centuries.
‘Dire Picture’
The warmest year on record remains 2024, at around 1.55°C above the pre-industrial average, which began under a strong El Niño. Global weather is currently under the influence of La Niña, which cools surface temperatures in the central and eastern equatorial Pacific. Forecasts indicate neutral conditions by mid-2026, with a possible El Niño developing before year’s end — which WMO scientific officer John Kennedy said could lead to elevated temperatures again in 2027.
WMO deputy chief Ko Barrett described the overall outlook as a “dire picture,” saying the indicators are not moving in a direction that provides much hope.
Guterres tied the climate crisis to the broader geopolitical moment, saying: “In this age of war, climate stress is also exposing another truth: our addiction to fossil fuels is destabilising both the climate and global security. Today’s report should come with a warning label: climate chaos is accelerating and delay is deadly.”
