Most of the climate change goes back to man -made greenhouse gas emissions and already has noticeable consequences for sea levels and temperatures on earth, confirms a new study. In order to limit global warming to a maximum of 1.5 degrees as planned, only around 130 billion tons of carbon dioxide may be added to the previous emissions, as the calculations show. At the current pace and amount of emissions, this CO2 budget would have been consumed in three years. The time window for climate protection closes quickly.
In 2015, the global community agreed to limit global warming to a maximum of 1.5 degrees compared to pre -industrial values. But this 1.5-degree threshold has already been exceeded, at least for one year: in 2024 the global annual temperature was 1.52 degrees above the pre-industrial level. At the same time, global greenhouse gas emissions do not go back, but continue to rise. Against this background, researchers of the “Indicators of Global Climate Change” (IGCC) initiative have been calculating regularly for several years how much greenhouse gases can still get into the atmosphere in order not to tear the climate protection goals of the Paris Agreement over several years. For your analyzes, take ten indicators of climate change. Now the IGCC team around Piers Forster from the University of Leeds has published the current figures.
CO2 budget is only enough for three years
The sobering result: The remaining emission budget of mankind has only been around 130 billion tons of carbon dioxide (GTCO 2 ) since the beginning of 2025. If we continue to release greenhouse gases in the current pace and scope, this budget would have been used up in just under three years. At the latest then the global emissions should have dropped to “net zero” in order to at least have a 50:50 chance of compliance with the 1.5 degree target, as the numbers show. In order to have at least an 83 percent chance, we should only emit only 30 GTCO 2 .
If we were to target maximum global warming of 1.6 or 1.7 degrees, the available CO2 budget would be slightly larger with 310 or 490 billion tons of carbon dioxide. However, this amount of CO2 could also be exceeded within nine years at the current level of emission, as the calculations showed. In addition, the climate system reacts to our greenhouse gas emissions with a delay. The global warming caused by today’s CO2 values only fully comes into play decades later, as well as their consequences as well as weather extremes.
Main driver: fossil raw materials and deforestation
The calculations of the IGCC team also confirm again that the current rapid climate changes are largely due to human activities-mainly through combustion of fossil fuels and deforestation. There are also natural fluctuations in the climate system. But the human influence ensures an unprecedented pace in global warming. “Both the heating levels and the speed of warming are unprecedented,” says Forster. The average global temperatures between 2015 and 2024 were 1.24 degrees above the pre -industrial level – of which 1.22 degrees caused by human activities. The value is made up of 1.79 degrees temperature rise ashore and 1.02 degrees in the seas.
“Global warming is already influencing the life of billions of people worldwide,” says Joeri Rogelj from Imperial College London. Because the excess warmth changes aspects of the earth system that are vital for ecosystems and people – including the oceans, ice sheets and permafrost. “Warmer water leads to an increase in sea level and to more intensive weather extremes,” explains Karina von Schuckmann from the Mercator Ocean International Political Counseling. Due to the higher sea level, for example, storm surges and erosion increase in coastal areas. Finally, the global middle sea level rose by 26 millimeters between 2019 and 2024 – this corresponds to four millimeters per year and is more than twice as much as the team determined. The long -term rate since the beginning of the 20th century is 1.8 millimeters per year.
Emissions have to drop faster
The last status report of the IPCC world climate also clearly showed that climate change has far -reaching negative effects on nature and humans. He also showed that greenhouse gas emissions have to be reduced quickly and massively to limit the heating to 1.5 degrees. “The temperatures have increased since the last IPCC report 2021 year after year-a clear sign that climate policy and the pace of climate protection measures are not sufficient to meet the increasingly serious effects,” says Forster.
“The time window to stay less than 1.5 degrees closes quickly,” says Rogelj. “The emissions in the coming decade will determine how soon and how quickly the 1.5 degrees will be reached. They have to be reduced quickly to achieve the climate goals of the Paris Agreement.” In the Paris schedule, it is planned that the participant countries are raising their national self -commitments (NDCS) for climate protection this year. However, how drastically the improvements will fail is still unclear and will probably only show up for the next World Climate Conference (COP30), which will take place in Brazil in November 2025.
Sources: IGCC, University of Leeds; Specialist articles: Earth System Science Data, DOI: 10,5194/ESSD-2025-250
