Worst US drought in 500 years fuels raging California wildfires

Record wildfires blazing across the American West are being caused by the worst drought in at least 500 years. US government scientists believe the conflagrations may herald an epochal, permanent change in the climate and landscape of the region, endangering the future of one of the richest areas on Earth.

Record wildfires blazing across the American West are being caused by the worst drought in at least 500 years. US government scientists believe the conflagrations may herald an epochal, permanent change in the climate and landscape of the region, endangering the future of one of the richest areas on Earth.

Nearly four million acres of forest, ranging from Alaska to southern California, have gone up in smoke this year, and the official fire season has only just begun. The year is expected to be the worst ever, breaking the previous record set in 2003. While cinema audiences have watched an unrealistic scenario of global warming causing a sudden ice age in New York in The Day After Tomorrow, scientists say that climatic change is precipitating a sharply contrasting real catastrophe on the other side of the country.

Last week 28 wildfires were burning over three million acres along the Pacific coast. Six wildfires were ablaze in California alone, charring 48,000 acres of land and forcing the evacuation of thousands of homes. In the tinder-dry conditions the slightest incident is setting off a conflagration. One of last week's blazes, which lasted for days, started when a red-tailed hawk was electrocuted by a power line and fell to the ground in flames. Another was ignited by a man dragging a piece of steel behind his car, another by target shooting and a fourth by fireworks.

Lightning is also sparking wildfires in Alaska and down the Pacific coast. And visitors to Yosemite National Park have been officially advised not to over-exert themselves because of the "very unhealthy quality" of the air, caused by pollution from fires.

Usually - as in the record blazes last year - the fires reach their peak in October. But this year they started unprecedentedly early. By early May there had been 77 fires in the state of Washington alone, compared to 22 last year.

By June, the conflagrations were already having political rami- fications. The governors of 18 states met in a crisis session to consider what to do. The fires have been sparked by abnormally hot weather, following five years of crippling drought. In early May air temperatures reached 40C (104F) in Long Beach, California - far eclipsing the previous record of 33 degrees - while earth in the south of the state baked to an astonishing 70C (158F).

The official US Geological Survey says that the drought is the worst in at least 500 years. The Colorado river, for example, is carrying only half as much water as in the notorious "Dust Bowl" drought of the 1930s. Utah's Lake Powell - the second biggest man-made lake in the country - has lost nearly 60 per cent of its water and, on present trends, will lose its ability to generate electricity in three years' time.

The drought has also created a record amount of tinder, in millions of trees killed off by huge plagues of beetles. The warm weather has increased the beetles' lifespans, while the drought stops the trees from mounting their only defence when they exude a sticky pitch if attacked. Whole forests have been killed from Alaska to Arizona.

Despite the Bush administration's scepticism, US government scientists have little doubt that climate change is to blame. "What we are seeing is consistent with what we expect to happen under global warming" says Evan Mills of the Lawrence Berkeley National Laboratory. "We expect more beetle infestation, more drought, more wildfires."

And Craig Allen of the US Geological Survey is among scientists who believe that climate change may be driving an epochal change, that last happened 13,000 years ago, when forests died off to be replaced by grasslands and desert scrub. "As the climate is changing, these ecosystems are rearranging themselves."

Research reported at a meeting of 100 of the West's top scientists in May concluded that the climate of the region had now "shifted from wet to dry" and predicted "multispecies die-offs". Some are suggesting the development of the Pacific coast, one of the richest on Earth, may prove to have been a gigantic "miscalculation".