An international team of Earth scientists has produced a new paper which looks at the impact of climate change on the world's ground water resources. The researchers found climate change may be exacerbating many countries' experience of water stress.

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The release of their paper coincides with the proclamation by Lord Stern, author of a seminal review of climate change's effects on the global economy, that he may have underestimated the threat posed by erratic weather. Stern told world leaders assembled at the World Economic Forum in Switzerland that he should have been "more blunt" when presenting the case for action to mitigate anthropogenic climate change in 2006.

Nevertheless, his paper proved pivotal in increasing awareness amongst policy makers of the need to act to tackle climate change when it was released seven years ago.

Diana Allen, co-author of Ground Water and Climate Change said, "Increasing food requirements to feed our current world's growing population and prolonged droughts in many regions of the world are already increasing dependence on groundwater for agriculture. Climate-change-related stresses on fresh surface water, such as glacier-fed rivers, will likely exacerbate that situation.

"Add to that our mismanagement and inadequate monitoring of groundwater usage and we may see significant groundwater depletion and contamination that will seriously compromise much of the world’s agriculturally-grown food supply."

Her prescient warnings follow similarly tenebrous findings by others; in August 2012, scientists conducting the first global analysis of water extraction reported in the journal Nature that demand for water has outpaced supply in the majority of the world's principal agricultural regions.   

Working with an international team of scientists, Dr Allen, who is based at Simon Fraser University in British Columbia, Canada produced research demonstrating how several human-driven factors, if not rectified, will combine with climate change to significantly reduce useable groundwater availability for agriculture globally. The researchers looked at groundwater supply records and mathematical models for climate change to arrive at their conclusions.

They said a number of factors make it virtually "impossible to forecast groundwater's long-range fate globally." However, painting a bleak picture of future prospects, Dr Allen's team suggested that groundwater recycling back into the ocean could cause a half -centimetre rise in sea levels each year. This, in addition to other causes of rising sea levels and the higher frequency of climate change-induced storm surges, may lead to more flooding of coastal areas, threatening the quality of some groundwater supplies and compromising their usability.

Dr Allen elaborated, "Over-pumping of groundwater for irrigation is mining dry the world's ancient Pleistocene-age, ice-sheet-fed aquifers and, ironically, at the same time increasing sea-level rise, which we haven't factored into current estimations of the rise."

The international research is assisting the Intergovernmental Panel on Climate Change, a UN Environment Programme initiative, which is monitoring the effect of climate change on groundwater availability, as well as the environmental and socioeconomic impacts this will have. Groundwater is an essential resource for many of the world's breadbasket regions.