Earth’s climate is increasingly out of balance, according to WMO’s State of the Climate

The Earth’s climate is more out of balance than at any time in observed history, says the State of the Climate report 2025 published today by the World Meteorological Organization (WMO). The report confirms that 2015–2025 were the eleven hottest years on record. Earth’s energy imbalance is at its highest level in the sixty-five-year observational record.

The report includes key observed global climate indicators: global temperature, greenhouse gases, ocean heat, sea level, ocean pH, sea-ice extent, glacier mass balance, and introduces a new indicator on Earth’s energy imbalance.

Data from monitoring stations, including ICOS, show that the three main greenhouse gases – carbon dioxide, methane and nitrous oxide – continued to increase in 2025. 

WMO reports that in 2024 – the last year for which consolidated global observations are available – the atmospheric concentration of carbon dioxide reached its highest level in the last 2 million years, and methane and nitrous oxide in at least the last 800,000 years.

Ocean heat at a record high level, glacier melt continues

The report highlights dramatic consequences of sea level rise, ocean warming and acidification. More than 91% of the excess heat is stored in the ocean, which acts as a major buffer against higher temperatures on land.

Ocean heat content reached a new record high in 2025 and its rate of warming more than doubled from 1960–2005 to 2005–2025. Over the past nine years, each year has set a new record for ocean heat content.

WMO also reports at or near a record low annual sea-ice extent in the Arctic. Antarctic sea-ice extent was the third lowest on record, and glacier melt continued unabated.

The report also emphasises climate change’s impacts on health. Climate change impacts mortality, livelihoods and ecosystems, and amplifies existing risks.

Photo by Kate Trysh on Unsplash.