Nature fights back against the invaders: Australian dream-builders ignored the power of the elements, with disastrous consequences, writes Robert Milliken

FOR the past five terrifying days, nature has taken its revenge in Australia. The firestorms that have raged for 600 miles along the seaboard of New South Wales have brought urban Australians face to face with a terrible truth about the fragility of the relationship with their ancient, rugged land.

The scale is unprecedented: more than one million acres burnt out, four people killed, hundreds injured, at least 150 homes destroyed, about 100,000 people displaced and Sydney, the country's largest city, on a war footing. As the air swirls with smoke and ash, Australians are asking how such a natural catastrophe could happen.

Even before the British colonised the shores of Sydney harbour in January 1788, fire had played a pivotal role in shaping the dry continent's landscape. For centuries, Aborigines used fire in a controlled way to drive out wildlife and allow their hunting grounds to regenerate. As European settlers expanded their frontiers, they used fire more brutally to clear land for towns and farms. In doing so, they sparked a spreading imbalance in the landscape's delicate equilibrium which has seen fire turn back on the invaders in a ferocious way many times this century.

Australia's heat and drought make it a land prone to fires, something the majority of the population, which lives along the east coast, often understands less than do outback dwellers. The country's indigenous and most predominant tree, the eucalyptus, provides ready- made fuel in the form of oil in bark and leaves that discharges into a vapour, causing explosive infernos that leap from tree to tree.

New South Wales embarked on a fire management strategy in the 1970s that involved controlled burning of selected forest areas during cooler months. In the Eighties, this was wound down after protests over smoke pollution in residential areas and objections from conservationists, who argued that the survival of some native plants and animals was threatened. So when the fires struck last week, there was a massive accumulation of unburnt fuel lining the floors of forests and national parks.

Sydney, more than any other comparable city, is built around corridors of such parks and bushland, some of which have survived largely intact since early settlement. Many of Sydney's 4 million citizens have built their great Australian dream homes in these leafy suburbs in the north and south of the city, providing a curious co-existence of humans and native wildlife in the heart of the metropolitan area.

All that was shattered last week. Freak weather, small brushfires, some started by careless humans, fuel overload and haphazard land management: once again, the clash of man and nature became a recipe for disaster. In the past few days, I have driven through fire-ravaged zones around Sydney and its inner northern suburbs.

The horrifying smoke palls over the F3 freeway north of Sydney, the 10-mile queue of stranded motorists rushing to protect their houses on the Central Coast, the bewildered faces of families evacuating their homes just six miles from the skyscrapers of Sydney's commercial centre all told the same story: the fire is always waiting to take charge if the rules are broken.

The eucalyptus trees, which have adapted to survive fires, will start sending out green shoots again from charred ruins within a fortnight. For the people, the recovery will take much longer.