Freak summers 'will happen regularly'
Costly extremes of weather will become the norm, study suggests
Tim Radford, science editor Monday January 12, 2004 The Guardian
The 2003 heatwave in Europe that killed at least 20,000 people and triggered losses of an estimated £7bn could be a taste of things to come, according to research released today.
Climate scientists from Zurich report in Nature online that the summer heatwave that broke all records in France, Germany and central Europe had been extremely unusual, even given the steady rise in average global temperatures over the past 150 years.
Christophe Sch?r and six colleagues said this increase could not explain why European thermometers had risen so high, and stayed at the danger level for so long. But the heatwave, of the kind experienced once in 450 years, may not have been a freak.
The Swiss researchers used computer-driven weather models to determine whether climate variability - the already large difference between weather extremes - was likely to increase with average temperature and growing concentrations of greenhouse gases. In one simulation they found that, towards the end of the century, every second summer could be as hot and as dry as 2003.
"The European summer climate might experience a profound increase in year-to-year variability in response to greenhouse forcing," they wrote. "Such an increase in variability might be able to explain the unusual European summer of 2003, and would strongly affect the incidence of heatwaves and droughts in the future. It would represent a serious challenge to adaptive response strategies designed to cope with climate change."
The 10 hottest years on record have occurred since 1991, and the Zurich report is the third in less than a week to underline the climate threat.
On Thursday, scientists warned that global warming posed a danger of extinction for a million vulnerable plants and animals. On Friday the government's chief scientist, Sir David King, said climate change was a more serious threat than global terrorism. A survey of storms, droughts, heatwaves and other natural disasters in 2003 supports Sir David's argument.
According to the insurance giant Munich Re, 700 natural disasters last year claimed 50,000 lives, almost five times as many as in in 2002, and cost $60bn (£33bn). The temperatures in Germany alone between July and August were of the kind that might be expected to happen only once in Europe in
450 years. By 2020, the insurance chiefs said, such heatwaves might be happening every 20 years."We will have to get used to the fact that hot summers like the one we had in Europe must be expected more frequently in the future," said Gerhard Berz, the head of the company's risks research team. "It is possible that they will have become more or less the norm by the middle of the century. The summer of 2003 was a summer of the future, so to speak."
The earthquake in Iran on Boxing Day and the heatwave in Europe accounted for most of the deaths last year. But other freak events took a huge toll. In September, Hurricane Isabel destroyed 360,000 homes on the US east coast, and a series of tornadoes in May caused $3bn worth of damage.
Heatwaves in India, Bangladesh and Pakistan took temperatures up to 50C (122F). In China floods along the Huai and Yangtze rivers swept through
650,000 homes and caused more than £4bn of losses. Forest fires scorched huge areas of Australia, southwestern Europe, Canada and the US. Fires in California alone cost the insurance industry $2bn (£1.1bn).