Global groundwater warming due to climate change is a critical issue, with groundwater temperatures projected to rise by 2.1°C between 2000 and 2100 under a medium emissions pathway. This warming affects groundwater-dependent ecosystems, water quality, and geothermal potential. The study uses a global heat-transport model to simulate groundwater temperatures and their response to climate change, revealing regional variations in warming patterns. Groundwater warming can lead to increased temperatures in surface water bodies, impacting aquatic ecosystems and drinking water quality. It also poses risks to human health through the growth of pathogens and may threaten ecosystems reliant on groundwater. However, the warming could also provide opportunities for geothermal energy production. The study highlights the need for further research and monitoring to understand the full implications of groundwater warming on global water resources and ecosystems.Global groundwater warming due to climate change is a critical issue, with groundwater temperatures projected to rise by 2.1°C between 2000 and 2100 under a medium emissions pathway. This warming affects groundwater-dependent ecosystems, water quality, and geothermal potential. The study uses a global heat-transport model to simulate groundwater temperatures and their response to climate change, revealing regional variations in warming patterns. Groundwater warming can lead to increased temperatures in surface water bodies, impacting aquatic ecosystems and drinking water quality. It also poses risks to human health through the growth of pathogens and may threaten ecosystems reliant on groundwater. However, the warming could also provide opportunities for geothermal energy production. The study highlights the need for further research and monitoring to understand the full implications of groundwater warming on global water resources and ecosystems.