In a stark warning, scientists highlight that without access to lakes or streams, one in four humans relies on underground reservoirs. However, as temperatures soar, these vital water sources face contamination risks.
An international study using a global heat transport model reveals that by 2100, up to 590 million people could depend on groundwater that fails to meet safe drinking standards due to warming. This underlines a critical yet often overlooked consequence of climate change on Earth’s land.
Hydrologist Dylan Irvine from Charles Darwin University emphasizes the need to broaden focus beyond weather events and water availability. The study underscores that warming groundwater can alter its chemical composition, potentially making it unsafe for consumption due to dissolved minerals, pollutants, and pathogens.
Already, 30 million people reside in regions where groundwater exceeds safe drinking guidelines. As temperatures rise, even more communities could face water that requires extensive treatment to be safe, impacting vulnerable populations disproportionately.
Under current emissions trajectories, between 77 to 188 million people may inhabit areas where groundwater quality falls short of safe standards by century’s end. In a worst-case scenario, exacerbated by high carbon emissions, this number could skyrocket to an alarming 588 million individuals.
While some regions with deep water tables may remain relatively protected, areas with shallow groundwater and rapid warming are at severe risk. The implications extend beyond mere inconvenience, potentially causing environmental oxygen depletion and facilitating bacterial growth.
To help visualize these projections, researchers have developed an interactive Google Earth Engine tool, enabling users to explore future groundwater conditions in their localities. The study concludes with a call to urgently safeguard groundwater resources globally, stressing the need for proactive measures to mitigate climate impacts on essential water supplies.
This research, led by geoscientist Susanne Benz from the Karlsruhe Institute of Technology, underscores the critical importance of addressing climate change’s impact on groundwater to ensure future water security for all.
Reference: Nature Geoscience.