26 July 2007 - International
— Computer models of how our world will react
to climate change have long predicted extreme
and shifting weather patterns. More heavy
rains in some areas, crippling drought in
others. A new study, published this week in
the journal Nature, compared recorded precipitation
to predicted precipitation - and confirmed
we're changing our weather.
Scientists studying climate change use highly
sophisticated computer models to predict likely
effects. For accuracy, these models are checked
against what we see happening in the real
world.
In this study, researchers compared what
14 different climate models predicted would
happen with actual documented changes in snowfall
and rainfall. What they found was a remarkably
close match. The conclusion - human caused
global warming is changing precipitation patterns.
As Peter Stott, one of the report's authors
and a climate scientist at the University
of Reading, told the Times, "The paper
is saying there is a significant human influence
on global rainfall patterns and this includes
an increase of precipitation north of 50 degrees
northern latitude, an area that includes the
UK".
Rain and drought
In effect, human induced climate change is
creating a stronger water cycle - pushing
water vapour from the hottest parts of our
planet towards the poles. So, wet areas are
getting wetter and dry areas are getting dryer.
The changes correspond to what's predicted,
but may be even worse than previously thought.
From the study:
"The observed changes, which are larger
than estimated from model simulations, may
have already had significant effects on ecosystems,
agriculture and human health in regions that
are sensitive to changes in precipitation,
such as the Sahel [region in northern Africa]."
-- "Detection of human influence on
twentieth-century precipitation trends",
Zhang et al, 2007, Nature.
So while millions of people in places like
the UK and parts of China are suffering from
flooding, heat wave fuelled forests fires
plague places like Greece and the western
United States.
Cool the planet
While, it's still not possible to connect
a specific weather event to climate change,
the study published this week in the journal
Nature is further confirmation that the more
fossil fuels we burn, the worse it is going
to get.
And although the climate emergency has already
begun, solutions are also at hand. What we
need is an energy revolution to get our global
warming emissions under control while still
leaving room for economic growth.
