The world is dangerously close to the 1.5°C warming limit set in the Paris Agreement. According to a comprehensive new report, human-caused warming will reach 1.37°C in 2025.
Based on analysis by more than 70 scientists from 56 institutions across 17 countries, the 1.5°C threshold will be exceeded around 2030 if emissions continue at their current level.
Carbon budget shrinking rapidly
The fourth edition of the Global Climate Change Indicators report, published today, tracks the key measurements showing how fast and why the climate is changing. The picture that emerges shows the Earth warming at an accelerating pace, almost entirely due to human activities.
Dr. William Lamb, a senior researcher at the Potsdam Institute for Climate Impact Research in Germany, notes that greenhouse gas emissions are at their highest level ever, predominantly caused by the burning of fossil fuels. Lamb says that investing in renewable energy and electrification gives governments the opportunity to both reduce emissions and build cleaner, more reliable and more secure energy systems.
The carbon budget refers to the total amount of carbon dioxide that can still be released into the atmosphere while keeping warming below 1.5°C compared to pre-industrial levels. As of early 2026, this budget is calculated at approximately 130 billion tonnes. At current emission levels, the budget is expected to be completely exhausted within about three years.
In 2024, global greenhouse gas emissions reached a record 56.8 billion tonnes of carbon dioxide equivalent, primarily from burning fossil fuels. Atmospheric concentrations of the three main greenhouse gases—carbon dioxide, methane and nitrous oxide—have increased since 2019, with carbon dioxide concentration rising to 425.6 parts per million.
"In short, we are emitting more greenhouse gases than ever before, which raises greenhouse gas levels in the atmosphere, trapping more and more heat and destabilising the world."
This assessment by Dr. Matt Palmer, a scientist at the UK Met Office, summarises the report's main warning.
Seas warming, levels rising
The report also reveals that the Earth's energy imbalance—the difference between heat entering the Earth and heat radiated back into space—has more than doubled in recent decades and has now reached a record level. This means the planet is storing heat faster than at any time since modern measurements began.
Dr. Karina Von Schuckmann of the French research institute Mercator Ocean International says this imbalance is causing changes in every component of the climate system, including ocean and land warming, permafrost thaw, ice loss and sea level rise.
Global sea level set another record in 2025. The total rise since 1901 has reached 23 centimetres, and the rate of increase is also accelerating. Because the oceans absorb most of the excess heat, average sea surface temperatures rose to the second-highest level ever recorded last year.
A new indicator added to this year's report also reveals the extent of marine heatwaves. The number of affected days more than tripled globally between 1991 and 2025. In 2025 alone, the world experienced 65 days of marine heatwave conditions that damage ecosystems, threaten fish stocks and disrupt the ocean-atmosphere systems that regulate the Earth's climate.
Land temperature rise also accelerating
The picture on land is no different. Average maximum land temperatures over the last decade are nearly half a degree higher than the previous decade. This is causing extreme heat to reach unprecedented levels worldwide.
Dr. Samantha Burgess of the Copernicus Climate Change Service states that almost all of the warming in the last decade is caused by human activities. According to Burgess, impacts on livelihoods and ecosystems are already being felt around the world, and these impacts will accelerate as temperatures continue to rise.
Data infrastructure also under pressure
The scientists behind the report also warn of a less visible but significant risk: the global datasets used to monitor these changes are themselves under threat.
It is noted that budget cuts, including the Trump administration's decision last year to suspend the US State Department's global air quality monitoring programme, could create dangerous gaps in the evidence base underpinning climate science and policy.
Dr. Chris Smith of the International Institute for Applied Systems Analysis says that without data, future assessments will be much harder to make, and that urgent climate action is needed more than ever.
