According
to the World Bank, one-third of the world's population already
suffers from chronic water shortages. This situation has
been predicted to be world's population over the next 30
years. By 2025, the group claims, some three billion people
-- or 40% of the world's population --
could be living in countries without sufficient water supplies,
leading to crop failures, diminished economic development
and even to regional conflicts as nations find it necessary
to fight for control over scarce water resources.
While
the scientific community is divided over many aspects of
the global warming theory, the effect of global warming
on precipitation levels is not one of them: Global warming
would mean more condensation and more evaporation, producing
more and/or heavier rains. Global warming, therefore,
could offer the answer to the water scarcity problem.
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The Earth from space formed from reflected sunlight |
While
the scientific community is divided over many aspects of the
global warming theory, the effect of global warming on precipitation
levels is not one of them: Global warming would mean more
condensation and more evaporation, producing more and/or heavier
rains. Global warming, therefore, could offer the
answer to the water scarcity problem.
If history is any indication, greater precipitation may be
only one of many benefits of global warming. For example,
between the 10th and 12th Centuries, when the temperature
of the planet was roughly 0.5 degrees Celsius warmer than
it is today, agriculture in North America and Europe flourished
and the southern regions of Greenland were free of ice, allowing
cultivation by Norse settlers. Evidence of this was found
in 1993 when scientists from the National Science Foundation-sponsored
Greenland Ice Sheet Project II extracted an ice core from
Greenland's ice sheet that spanned more than 100,000 years
of climate history. Samplings from the core suggest that a
Little Ice Age began between 1400 and 1420, blanketing the
Vikings' farms in ice and forcing them to abandon their farms
in search of more hospitable climates. Prior to the onset
of this Little Ice Age, temperatures were comparable to the
temperatures general circulation models used by the U.N.-sponsored
Intergovernmental Panel on Climate Change (IPCC) have projected
for 2030-2050.
Global warming could also mean greater agricultural productivity
and greater water conservation. CO2 acts as a fertilizer on
plant life while reducing plant transpiration (the passage
of water from the roots through the plant's vascular system
to the atmosphere). Thus, with global warming, agricultural
output could be expected to increase while making fewer demands
on the water supply.
‘Global Warming’. An OpenLearn chunk used/reworked
by permission of The Open University copyright © (2007).’
http://creativecommons.org/licenses/by-nc-sa/2.0/uk/
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