Climate research – time for a new paradigm?

Overall, climate science is successful, as it saw the central consequences of the CO₂-Siegs in the atmosphere astonishingly good. For example, 40 years ago, the climate models predicted that the Arctic would warm up much faster than the rest of the earth. The same applies to the land masses compared to the oceans and the mountains compared to lower areas.

Regional, however, the climate develops differently in many places: the common climate models do not provide an explanation of why, blocking weather conditions frequently in summer- in which high and low pressure areas hardly move- nor are South Africa increasingly haunted by Dürren. Some regional developments exceed all the forecasts in their intensity: the heat extreme in Central Europe increases more than expected. Although it is also known that it will rain more and more with rising temperatures, but the models do not provide any information about where.

Deviations from the climate models indicate crucial gaps in knowledge.

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How can such deviations be classified by the predictions? The professor deals with this question at the Geophysical Institute of the University of Chicago, Tiffany Shaw, and the director of the Max Planck Institute (MPI) for meteorology in Germany, Bjorn Stevens, in one Articlewhich recently appeared in the “Nature” journal. Because the reliable predictions as possible are important for regions, countries and municipalities in order to plan, guarantee nutritional safety and to protect their people against drought and floods if possible.

»How variable can climate be? Are there any three years of drought in this country (as they existed in 2018, 2019 and 2020, ed. A.) without climate change? «Asks Stevens. “If the models cannot reflect this or you have to run it 10,000 times until this type of changes arise, then the model is probably wrong,” he explains. Or at least such deviations indicate decisive knowledge gaps that need to be closed. “The challenge for the conceptual work will be to find out which physics, which is missing in the standard approach, is most important for regional changes and how we can include them,” says the meteorologist. Because in this discipline there is a “strange mixture” of physical models for large -scale processes and statistical for the small -scale. The latter would also have to be mapped more physical.

There are particularly large discrepancies for the climate models in the tropics. That surprises little, since so far it has been significantly less research than in the middle latitudes and the polar regions. That should change now. In 2024, the MPI started a large field trial over the tropical Atlantic. The aim of the “Orcestra” project is to deepen the understanding of the inner -tropical convergence zone (ITCZ) there. This is part of the Hadley circulation, a global air flow system. The ITCZ ​​is of central importance for the world climate because it distributes warmth and moisture over the whole globe and ensures a third of all rainfall. It is assumed that it changes with global warming. However, the climate models have difficulties to give more precise forecasts, because the processes in the ITCZ ​​are highly complex. One of the keys for previously inexplicable developments in other parts of the world may be one.

According to the two scientists, it is also conceivable that similar to the time in physics, when quantum physics was created, climate science is in a crisis and has to revise its paradigm. This is based on the assumption that statistical mean values ​​determine the small -scale processes dependent on the large -scale processes. Certain regional processes may play a larger role than expected.

However, it is important for the researchers to emphasize that the deviations found from the climate models do not question the physical basics of the discipline. If we want to counteract global warming, we have to reduce the emissions of greenhouse gases.