The impact of our warming climate on global groundwater temperatures
- 1Institute of Photogrammetry and Remote Sensing, Karlruhe Instiute for Technology, Karlsruhe Germany
- 2Research Institute for the Environment and Livelihoods, Charles Darwin University, Casuarina, Australia
- 3School of Environmental and Life Sciences, The University of Newcastle, Newcastle, Australia
- 4Department of Applied Geology, Martin Luther University Halle-Wittenberg, Halle, Germany
- 5Institute of Applied Geosciences, Karlsruhe Institute of Technology, Karlsruhe, Germany
- 6Centre for Water Resources Studies, Dalhousie University, Halifax, Canada
- 7Department of Functional & Evolutionary Ecology, University of Vienna, Vienna, Austria
Groundwater, the largest reservoir of unfrozen freshwater on Earth, plays a crucial role in supporting life and ecosystems. Its thermal regimes influence various environmental processes, impacting groundwater-dependent ecosystems, geothermal potential, and groundwater quality. Despite its significance, little is known about how groundwater responds to surface warming across spatial and temporal scales. Here we present a comprehensive analysis of global groundwater temperature patterns, utilizing the latest CMIP6 scenarios.
In this study we developed the first global model of groundwater temperature patterns, combining analytical solutions to conductive heat transport with high-resolution maps of ground thermal diffusivity and geothermal gradient. This model, validated with over 8,000 groundwater temperature measurements, allows users to estimate present and future temperature depth profiles globally. Past trends show a median global groundwater temperature increase of 0.3 °C over the last two decades. When simulating projected groundwater temperatures globally, our model reveals an average warming of 2.2°C (SSP 245) to 3.8°C (SSP 585) between 2000 and 2100 at the depth of the water table. Regional variations are substantial due to climate change and water table depth variability, with mountainous regions exhibiting the lowest warming rates. These distinct regional variations emphasize important thermal controls and the need for localized analysis.
Our work sheds light on the importance of understanding groundwater warming patterns, identifying 'hot spots' that may pose risks to both ecosystems and human well-being. In this study we also offer a specific focus on Europe, providing averages to enhance regional relevance and address emerging challenges in groundwater quality and habitat preservation.
How to cite: Benz, S. A., Irvine, D. J., Rau, G. C., Bayer, P., Menberg, K., Blum, P., Jamieson, R. C., Griebler, C., and Kuryly, B.: The impact of our warming climate on global groundwater temperatures, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-4000, https://doi.org/10.5194/egusphere-egu24-4000, 2024.
