The areas most likely to experience drier
climates and more prolonged droughts include the Mediterranean, the
Middle East, the southern USA and southern China.
Southern India, western China and parts of
east Africa could experience what one author, Simon Gosling of the
University of Nottingham, UK, calls “substantial increases in available
Neither such predictions of drought nor
the admissions of uncertainty are in any way new. The significance of
the latest research perhaps lies in its scale, its thoroughness and the
fact that it confirms, once again, the unhappy picture of climate change
in a world which resolutely goes on burning fossil fuels (this is always
called “the business as usual” scenario”).
The study incorporated five global climate
models to simulate ways in which climate change might affect flood
hazard, drought, water scarcity, agriculture, ecosystems and even the
spread of malaria.
The interpretations of such simulations
are always spoken of in terms of “signal to noise ratio” and of “global
hotspots”; and of probabilities and trends rather than predictions. But
the overall conclusion is that drought severity is on the increase and
some places are going to feel the impact of climate change worse than
The research was led by Christel Prudhomme
of the UK Centre for Ecology and Hydrology, who said: “Our study shows
that different representations of terrestrial water cycle processes in
global hydrological models are responsible for a much larger uncertainty
in the response of hydrological drought to climate change than
previously thought. We don’t know how much changed climate patterns will
affect the frequency of low flows in rivers.”
A warmer world inevitably means more
evaporation, and warmer air temperatures mean that the capacity of the
atmosphere to carry water vapour will also increase.
But where the extra water will fall is
still unresolved. “More water under climate change is not necessarily
always a good thing”, says Simon Gosling.
“While it can indeed help alleviate water
scarcity, assuming you have the infrastructure to store it and
distribute it, there is also a risk that any reductions in water
scarcity are tempered by an increase in flood hazard.”
Source: Climate News Network