The ‘Earth’s climate swings increasingly out of balance’, according to todays’ headline of the press release of the World Meteorological Organization. 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. Now, much more energy is coming in than going out. 

2024 was the warmest year in the 176-year observational record, at about 1.55 °C above the average global temperature at the end of the 19th temperature, the reference before the start of human-caused climate change. The year was relatively warm because of a strong El Niño. In 2025, without this El Niño effect, man-made global warming was about 1.43 °C.

This warming of the atmosphere represents just 1% of the excess energy. 5% is stored in the continental land masses and 3% of the excess energy warms and melts ice. Annual sea ice extent in the Arctic was at or near a record low, Antarctic sea ice extent was the third lowest on record, and glacier melt continued unabated, according to the report.

The numbers are most dramatic for the oceans: More than 91% of the excess heat that reaches our planet is stored in the oceans, even up to a depth of 2000 metres. Each year for the past two decades, the oceans have been absorbing the equivalent of about eighteen times the annual human energy use. The oceans’ rate of warming has more than doubled from 1960-2005 to 2005-2025. ‘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 WMO concludes.  

The consequences of ocean warming include degradation of marine ecosystems, biodiversity loss, more catastrophic tropical and subtropical storms, and a faster decline of sea ice in the polar regions. As a result of the warming ocean and melting ice, global mean sea-level rise has accelerated since satellite measurements began in 1993.

The water of the oceans is also becoming increasing acidic because of the absorption of carbon dioxide. Around 29% of the CO2 from human activities between 2015–2024 was absorbed by the oceans.

Source: State of the Global Climate 2025. World Meteorological Organization, 2026.