Global groundwater stock under threat of overexploitation and pollution, says UN report
Despite accounting for 99% of all liquid freshwater on Earth, global groundwater sources are under threat of overexploitation and pollution according to the 2022 edition of the United Nations World Water Development Report.
The report says groundwater already provides half of the volume of water withdrawn for domestic use by the global population, and reliance on it will increase, mainly due to growing water demand by all sectors combined with increasing variation in rainfall patterns. But the rate of global aggregated groundwater storage depletion is currently estimated at roughly 15 to 25% of total groundwater withdrawals and pollution is “widespread”.
While groundwater aquifers are often privately owned and straddle national boundaries the report asserts that “Governments need to fully assume their role as resource custodians in view of the common-good aspects of groundwater.”
Groundwater pollution reduces the source’s suitability for drinking and also affects groundwater-dependent ecosystems. Agricultural pollution, the report says, is “widespread” according to the report and has overtaken contamination from settlements and industries as the major factor in the degradation of inland and coastal waters. Pollutants include nitrate from chemical and organic fertilizers, as the most prevalent anthrapogenic contaminant in groundwater globally. The report highlights that groundwater pollution is a virtually irreversible process.
Despite concern about pollution and over abstraction, groundwater monitoring was held up by last year by the United Nations as a “neglected area” the report says.
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