CSIRO News (Australia): In a paper published today in the
journal Science, Australian scientists from the Commonwealth Scientific and
Industrial Research Organisation (CSIRO) and the Lawrence Livermore National
Laboratory, California, reported changing patterns of salinity in the global
ocean during the past 50 years, marking a clear fingerprint of climate change.
Lead author, Dr Paul Durack, said that by looking at
observed ocean salinity changes and the relationship between salinity, rainfall
and evaporation in climate models, they determined the water cycle has
strengthened by four per cent from 1950-2000. This is twice the response
projected by current generation global climate models.
"Salinity shifts in the ocean confirm climate and the
global water cycle have changed. These changes suggest that arid regions have
become drier and high rainfall regions have become wetter in response to
observed global warming," said Dr Durack, a post-doctoral fellow at the
Lawrence Livermore National Laboratory.
With a projected temperature rise of 3ºC by the end of the
century, the researchers estimate a 24 per cent acceleration of the water cycle
is possible.
Scientists have struggled to determine coherent estimates of
water cycle changes from land-based data because surface observations of
rainfall and evaporation are sparse. However, according to the team, global oceans
provide a much clearer picture. "Warming of the Earth’s surface and lower
atmosphere is expected to strengthen the water cycle largely driven by the
ability of warmer air to hold and redistribute more moisture."....
Cloud photo by Yamoto, Wikimedia Commons, under the Creative Commons Attribution-Share Alike 3.0 Unported
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