Karlsruhe Institute of Technology: As a result of climate change, there is a risk of falling groundwater levels in Germany

The experts from BGR and KIT used artificial intelligence in various forecast models to investigate how climate change will affect groundwater resources in Germany in the 21st century. To do this, they used machine learning (deep learning) methods to evaluate the development of the groundwater level for various locations on the basis of existing groundwater data from all over Germany using different climate scenarios that come from the fifth assessment report of the IPCC. These ranged from an assumed warming of the global mean temperature by the year 2100 of less than two degrees Celsius, as defined by the Paris Climate Agreement as a target, to a medium forecast model (plus 2.6 degrees) to the so-called business as usual scenario, which, without appropriate climate protection measures, assumes a warming of up to five degrees compared to the pre-industrial state. “Only direct climatic influences and changes were included in the scientific investigation, while we did not include anthropogenic factors such as groundwater extraction,” emphasizes Andreas Wunsch from the Institute for Applied Geosciences (AGW) of KIT and first author of the study.


According to the experts, all three climate scenarios examined lead to more or less strong developments with drought effects, falling groundwater levels and changed water availability. While the two more optimistic scenarios show less pronounced and numerically less clear tendencies, the experts from KIT and BGR determined a trend towards significantly decreasing groundwater levels for most locations in the case of the strongest of the three warming scenarios. “Especially for the near future, the results of this forecast are very relevant, since this scenario comes closest to the current situation,” emphasizes Dr. Tanja Liesch from AGW.

“The future negative effects are particularly visible in northern and eastern Germany, where there are already corresponding developments. Here, especially towards the end of the century, there is a risk of longer periods with low groundwater levels,” emphasizes Dr. Stefan Broda from the BGR. This situation does not occur to this extent in the two weaker warming scenarios. For the experts from KIT and BGR, this is an indicator that a reduction in greenhouse gas emissions can have a positive effect on future groundwater levels.