11-Year Run of Record Global Heat Continues: UN Agency

The thawing of ice is accelerating in Antarctica due to increasing temperatures.

The past 11 years have been the warmest in the modern era, with oceans continuing to heat up as well, according to the UN’s weather agency.

The World Meteorological Organization (WMO) said on Wednesday that 2025 was among the three warmest years ever recorded, extending a prolonged period of extraordinary global temperatures.

After analysing eight international datasets, the organisation reported that global average surface temperatures in 2025 were about 1.44°C above the 1850–1900 average.

Two of the datasets ranked 2025 as the second warmest year in the 176-year record, while the remaining six placed it as the third warmest.

Warm Despite La Niña

The fact that 2025 was slightly cooler than the three-year average from 2023 is partly attributed to the La Niña phenomenon, which is typically associated with cooler conditions.

However, the WMO stressed that any temporary cooling linked to La Niña has not reversed the long-term warming trend.

“The year 2025 began and ended with a cooling La Niña, yet it was still one of the warmest years on record globally due to the accumulation of heat-trapping greenhouse gases in the atmosphere,” said WMO Secretary-General Celeste Saulo.

The organisation added that persistently high temperatures on land and sea helped fuel extreme weather events last year, including heatwaves, heavy rainfall, and deadly tropical cyclones, underscoring the need for robust early warning systems.

Ocean Heat

Citing a separate study, the WMO noted that ocean temperatures were also among the highest on record in 2025, reflecting the long-term buildup of heat within the climate system.

Regionally, around 33 per cent of the global ocean area ranked among its top three warmest conditions during the 1958–2025 period, while about 57 per cent fell within the top five. These included the tropical and South Atlantic Ocean, the Mediterranean Sea, the North Indian Ocean, and the Southern Ocean, highlighting widespread warming across ocean basins.

The WMO said it will publish full details of key climate indicators—including greenhouse gas concentrations, surface temperatures, ocean heat content, and related trends—in its State of the Global Climate 2025 report, due for release in March.