"The natural climate fluctuation El Niño, which brings higher temperatures, subsided by mid-2024. Nevertheless, global warming appears to be strong again this year. The main reason are the still high greenhouse gas emissions," says Gottfried Kirchengast, climate researcher at the Wegener Center and Institute of Physics at the University of Graz. Together with his doctoral student Moritz Pichler, he recently presented a new reference data set and a method in a highly regarded publication that allows global warming to be predicted more accurately and earlier than ever before. Now, for the first time, the researchers are providing current forecasts for 2025 well before the end of the year. "Our calculations include observational data up to August and seasonal forecasts from September onwards. They show, with 90 percent probability, an increase of 1.48 °C plus/minus 0.09 °C compared to pre-industrial levels for this year," says Pichler, presenting the annual forecast.
Crucial years for the Paris Climate Agreement
In addition to the temperature increase with a view to 2025 alone, the researchers also have a current forecast for long-term global warming. This refers to the average increase in global surface air temperature over a period of 20 years. The Intergovernmental Panel on Climate Change (IPCC) uses this measure to assess the fulfilment of the Paris climate goals. "According to our results, this long-term warming is currently 1.47 °C plus/minus 0.10 °C. And looking ahead, our projection to 2034 based on the data up to 2025 shows that we will exceed the 1.5 °C limit with over 95 percent probability already before 2030," says Kirchengast, adding: "In the latest IPCC Report, the 1.5 °C limit was still expected to be reached between 2030 and 2035."
Since human-made greenhouse gas emissions are the key driver of this dangerous development, it can only be slowed down by their drastic reduction. Complementary scenarios inspected by the researchers make it clear that if current emissions continue, even the 1.7 °C threshold will be exceeded before 2035. This would mean that also the Paris Agreement's goal of limiting global warming to "well below 2 °C" would not be achieved. "Only if we more than halve emissions by 2035 can we stay below 1.7 °C afterwards and get back below 1.5 °C in the second half of the century," warns Kirchengast, emphasizing: “Serious climate action contributions to fulfil the Agreement have never been so urgent, and political leaders are more challenged than ever. Failure would be a crime against the generation of our children.”
The reference data set for these forecasts and other key data on climate change are freely accessible and available worldwide via the Graz Climate Change Indicators – ClimateTracer web portal. The Graz Climate Change Indicators project is part of the Field of Excellence “Climate Change Graz” at the University of Graz.
The publication on the new method for computing global warming:
G. Kirchengast & M. Pichler: A traceable global warming record and clarity for the 1.5 °C and well-below-2 °C goals, 2025
