Europe heating up quicker than thought
Pastor Dale Morgan
Europe heating up quicker than thought*
By Michael Kahn in London
August 04, 2007 03:37am
Article from: Reuters
WESTERN Europe has heated up more than previously thought over the past
century, according to a new study that adds to evidence pointing to a
future of hotter summers and longer-lasting heatwaves.
The study, published yesterday in the Journal of Geophysical
Research-Atmospheres, showed that the actual mean temperature since 1880
had risen 1.6C, not the 1.3C as previously thought, said Paul
Della-Marta, a climate scientist at Switzerland's national weather
service who led the study.
“It is a big change when you consider it is an average temperature,” Mr
Della-Marta said.
The reason why previous estimates were too low was because before 1930
most temperatures were measured without the type of screens now in use
that block radiation from the sun and ground that can skew a reading, he
said.
The study's findings may provide further evidence that heatwaves like
the one that killed dozens this summer in Europe were a sign of global
warming.
“It could be used as more evidence that temperatures are rising and we
may be underestimating impacts of human activity,” he said.
Weather forecasters may also use the new data to help build climate
models to help better predict the impact rising temperatures will have,
Mr Della-Marta added.
“We would expect the frequency and duration of heat waves to increase
with global warming at an accelerated rate,” he said in a telephone
interview.
“It means it is getting hotter and that extreme events are getting more
frequent.”
The team, which also included researchers from the University of Bern,
compiled temperature readings from more than 200 locations across Europe
and found that heatwaves now lasted an average of three days compared to
around 1.5 days in 1880.
The researchers defined a heatwave as periods when temperatures rose
above a certain level, which varied depending on the location.
For example, the threshold was 30.7C in Paris and 35C in Madrid.
Because many of the stations - which stretched from Sweden to Croatia -
recorded temperatures in the same regions, the team was able to strip
out off-the-mark temperatures and come up with a more accurate reading,
Mr Della-Marta said.
“We applied statistical methods capable of identifying these changes.
"Our method looked carefully at the range and by comparing one station
to another we found some that had problems with their temperatures.”