Nearly one out of four people depend on groundwater for survival, relying on it in the absence of streams, dams, and freshwater lakes. However, an alarming study indicates that by the end of this century, tens to hundreds of millions may be deprived of this vital resource as rising temperatures make it toxic and undrinkable.
The Global Heat Transport Model
An international team of researchers developed a global-scale model of heat transport to measure temperature changes in groundwater sources under different warming conditions. Their findings reveal a dire future: around 590 million people could be relying on water sources that may not meet the strictest standards for potable water by 2100.
The Hidden Danger of Warming Groundwater
Dylan Irvine, a hydrologist from Charles Darwin University in Australia, highlights the overlooked impact of climate change on groundwater: “A lot of focus on climate change has rightfully been on weather events and water availability, but we need to think more broadly about its impact on groundwater.”
Groundwater warming can have catastrophic consequences. Water trapped within porous rocks can be filled with dissolved minerals, pollutants, and pathogens. Even a slight increase in temperature can deplete oxygen, fostering the growth of dangerous bacteria and leading to the dissolution of heavy metals like manganese and arsenic.
Current and Future Risks
Susanne Benz, a geoscientist at the Karlsruhe Institute of Technology in Germany and the study’s lead author, states: “There are already about 30 million people living in regions where the groundwater is warmer than stipulated in the strictest drinking water guidelines.” This means the water may not be safe to drink without treatment, such as boiling.
Even regions with adequate surface reservoirs could face altered dynamics in water safety due to heated groundwater discharges.
The Shared Socioeconomic Pathway
The study warns that under the ‘shared socioeconomic pathway,’ the current figures could double, with 188 million people living in areas where groundwater fails to meet strict drinkability standards by 2100.
Conclusion
This critical research underscores the urgent need to address the overlooked issue of groundwater warming. With millions at risk of losing access to safe drinking water, immediate and comprehensive actions are essential to mitigate the impact of climate change on our vital groundwater resources.