Earth’s thermometer shatters records as scientists warn of accelerating death march

The planet is running a fever that will not break.

An international team of researchers published data Thursday showing that human activities pushed global warming to 1.37 degrees Celsius above pre-industrial levels in 2025. The Earth’s energy imbalance, the measure of heat accumulating in the climate system, has more than doubled since the period from 1976 to 1995.

The report, the fourth annual update from the Indicators of Global Climate Change project, paints a picture of a world already committed to temperatures its inhabitants have never experienced.

The Indicators of Global Climate Change provides yearly updates on the state of the atmosphere and how it’s being affected by human activities, using key climate indicators from the Intergovernmental Panel on Climate Change (IPCC).

Greenhouse gas emissions reached 56.8 billion tonnes of carbon dioxide equivalent in 2024, the most recent year with complete data. That is an all-time high. Atmospheric carbon dioxide concentrations hit 425.6 parts per million in 2025. Methane reached 1,936 parts per billion. Both continue climbing.

The researchers project that human-induced warming will surpass 1.5 degrees Celsius in about four years. That threshold, enshrined in the Paris Agreement as a guardrail, is now essentially in the rearview mirror.

“The entire climate system is continuing to heat,” the authors wrote. The language is clinical. The meaning is not.

Sea levels have risen 23 centimeters since 1901. That is a new record. The rate of rise is accelerating. The number of days each year that the ocean experiences marine heatwaves has more than tripled globally between 1991 and 2025. In 2025 alone, the world’s oceans suffered through 65 days of marine heatwave conditions.

The researchers, led by Piers Forster at the University of Leeds, track 12 key indicators of the climate system using methods developed for the Intergovernmental Panel on Climate Change’s Sixth Assessment Report. They update those indicators annually. The news gets worse every time.

For the decade spanning 2016 to 2025, observed warming relative to 1850 to 1900 averaged 1.26 degrees Celsius. Of that, 1.24 degrees was caused by humans. The rate of human-induced warming over that decade reached 0.27 degrees Celsius per decade, matching the all-time high in the instrumental record.

That rate means a child born today will live in a world that is roughly 3 degrees Celsius warmer by the time they reach middle age, assuming emissions do not decline.

The report includes a new indicator this year: marine heatwave days. The addition is not academic. Marine heatwaves kill coral reefs, displace fish populations and disrupt the weather over land. They are becoming the new normal.

The researchers note that reductions in aerosol pollution, while beneficial for human health, have removed some of the cooling effect that masked the full force of greenhouse gas warming. The mask is off. The face beneath is not forgiving.

“The high rate of warming matches the all-time high seen last year in the instrumental record,” the authors state. They attribute it to a combination of record greenhouse gas emissions and reductions in aerosol cooling.

There is a sliver of what might be called good news. The growth of carbon dioxide emissions is slowing. That is not the same as emissions declining. It means the rate of increase is decelerating. The emissions themselves remain at historic highs.

The researchers make no effort to soften the implications. Human-induced warming reached 1.37 degrees Celsius in 2025. The remaining carbon budget for staying below 1.5 degrees Celsius with a 50 percent likelihood is just 130 gigatonnes of carbon dioxide. At current emission levels, the world will exhaust that budget in a little more than three years.

The data are open and accessible. The methods adhere closely to IPCC standards. The conclusion is inescapable.

The scientists also issue a warning that has nothing to do with physics and everything to do with human choices. The monitoring systems that produce these data are threatened by geopolitical decisions and funding cuts. Ocean measurements. Satellite observations. The very instruments that tell humanity how fast it is destroying its only habitat.

Those instruments are not luxuries. They are the canaries. And the canaries are gasping.