Global Warming Hit 1.37°C in 2025, on Track to Pass 1.5°C by 2030

Warming Accelerates as Heat Piles Up

The planet is heating faster than at any point in the modern record. The fourth edition of the Indicators of Global Climate Change report, released in Bonn and published on 11 June 2026 in the journal Earth System Science Data, finds that human-caused global warming reached 1.37°C in 2025. Compiled by more than 70 scientists, the report concludes that warming is now accelerating at roughly 0.27°C per decade over the 2016–2025 period, a pace described as unprecedented.

The headline indicator is the Earth's energy imbalance, a measure of how quickly heat is building up in the climate system. "Without human influence, it should be close to zero, but it has been growing since the 1970s and is now at a record high, doubling in recent decades," said Professor Piers Forster, Director of the Priestley Centre for Climate Futures at the University of Leeds and the report's lead author.

Emissions at an All-Time High

Global greenhouse gas emissions hit a record 56.8 billion tonnes of CO2 equivalent in 2024, driven mainly by fossil fuel combustion. Atmospheric CO2 reached 425.6 parts per million in 2025, while methane climbed to 1,936.3 parts per billion. The report finds that nearly all warming over the past decade was human-caused, with human-induced warming averaging 1.24°C over 2016–2025 against total observed warming of 1.26°C.

A Shrinking Carbon Budget

The remaining carbon budget to keep warming below 1.5°C is estimated at just 130 gigatonnes of CO2 from the start of 2026 — roughly three years of current emissions. The World Meteorological Organization had already confirmed in March 2026 that 2015–2025 were the hottest 11 years on record.

Rising Seas and Marine Heat

The report documents accelerating consequences. Global sea level rise reached a new record of 23 centimetres since 1901, and the number of marine heatwave days globally has more than tripled between 1991 and 2025. Dr Chris Smith of the International Institute for Applied Systems Analysis warned that many of the datasets underpinning climate monitoring are now threatened by funding decisions, calling for "concerted international action and coordination to ensure the continuity of observations of the climate."