Climate change and Groundwater fate
Simon
Fraser University earth scientist Diana Allen, a co-author on a new paper about
climate changes' impacts on the world's ground water, says climate change may
be exacerbating many countries' experience of water stress. "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," says Allen. "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."
In Ground Water and Climate Change, Allen
and several other international scientists explain how several human-driven
factors, if not rectified, will combine with climate change to significantly
reduce useable groundwater availability for agriculture globally.
The paper was published in late 2012 in the journal Nature Climate Change.
The
authors note that inadequate groundwater supply records and mathematical models
for predicting climate change and associated sea-level-rise make it impossible
to forecast groundwater's long-range fate globally.
"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," says Allen. "Groundwater pumping reduces the amount of
stored water deep underground and redirects it to the more active hydrologic
system at the land-surface. There, it evaporates into the atmosphere, and
ultimately falls as precipitation into the ocean."
Current
research estimates oceans will rise by about a metre globally by the end of the
century due to climate change. But that estimation doesn't factor in another
half-a-centimetre-a-year rise, says this study, expected due to groundwater
recycling back into the ocean globally.
Increasing
climate-change-induced storm surges will also flood coastal areas, threatening
the quality of groundwater supplies and compromising their usability.
This is
the second study that Allen and her colleagues have produced to assist the
Intergovernmental Panel on Climate Change (IPCC) in assessing the impact of
climate change on the world's groundwater supply.
The
IPCC, established by the United Nations Environmental Programme and the World
Meteorological Organization in 1988, periodically reviews the latest research
on climate change and assesses its potential environmental and socio-economic
impacts.
This
study is one of several guiding the IPCC's formulation of upcoming reports, the
first being about the physical science behind climate change, due Sept. 2013.
Source: Simon
Fraser University
Posted by Unknown
on Tuesday, January 29, 2013.
Filed under
Earth And Climate
.
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