Europe hotter than thought in past century

By Michael Kahn

LONDON (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 heat waves.

The study, published on Friday in the Journal of Geophysical Research-Atmospheres, showed that the actual mean temperature since 1880 had risen 1.6 Celsius degrees, not the 1.3 degrees 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," 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 heat waves 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, 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."