Groundwater resources are directly affected by climate change. In Germany, too, there is a threat of declining groundwater levels in the coming decades. This is the result of a study by the Karlsruhe Institute of Technology (KIT) and the Federal Institute for Geosciences and Natural Resources (BGR), which has now been published in the scientific journal Nature Communications.
The experts from BGR and KIT had 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 deep learning methods to evaluate the development of groundwater levels at various locations on the basis of existing groundwater data from all over Germany using different climate scenarios taken from the IPCC’s Fifth Assessment Report.
These ranged from an assumed warming of the global mean temperature by the year 2100 of less than two degrees Celsius, as defined as a target by the Paris Climate Agreement, to a medium forecast model (plus 2.6 degrees) to the so-called business as usual scenario, which assumes a warming of up to five degrees compared to the pre-industrial state without appropriate climate protection measures.
“Only direct climatic influences and changes were included in the scientific study, while we did not include anthropogenic factors such as groundwater withdrawals.”
- Andreas Wunsch of the Institute for Applied Geosciences
Projections show declining groundwater levels regardless of scenario
According to the experts, all three climate scenarios studied lead to more or less severe developments with drought effects, declining groundwater levels and changing water availability. While the two more optimistic scenarios show less pronounced and numerically less clear trends, the experts from KIT and BGR noted a trend toward significantly decreasing groundwater levels for most sites in the case of the strongest of the three warming scenarios. “Especially for the near future, the results of this forecast are very relevant, as 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 today. Here, longer periods of low groundwater levels are imminent, especially toward the end of the century,” emphasizes Dr. Stefan Broda of the BGR. This situation does not occur to this extent in the two weaker warming scenarios. For the experts, this is an indicator that a reduction in greenhouse gas emissions can have a positive effect on future groundwater levels.
