esert peoples, more than any others - except perhaps the Inuit of the Arctic - have mastered the art of surviving in extreme conditions. And they have done so by living in harmony with their environment. Often derided as 'primitive' by 'modern' affluent people, desert cultures actually have much to teach the modern world. And, as the stresses on the planet get ever more severe, their lessons will become ever more urgent and important.

The Bedouin of the Middle East and Northern Africa, for example, migrate from oasis to oasis to pasture their livestock, allowing each grazed area to recover, and using their acute understanding of weather patterns to go where new rain has fallen. Their animals provide food, clothing and even shelter: water-resistant tents are woven from goats' hair. Their traditional clothes - usually a long white tunic, sleeveless cloak and head cloth - both protect their skin from the sun and prevent dehydration from evaporating sweat.

Aborigines in the dry heart of Australia, similarly, have to be expert in their harsh environment to survive. They know the roots and trees that yield water, how to harvest dew, and even get refreshment from water-holding frogs. In the same way, they can hunt by following the faintest tracks, imitating animal movements and camouflaging themselves. The Bushmen of the Kalahari desert - who mainly eat fruits, nuts and roots - also get water from tree trunks and wring it from plants.

On the other side of the world, the Hopi people of the southwestern United States live in durable and cool specially constructed houses made from stone and sun-dried mud bricks.

But desert peoples are increasingly threatened, as 'civilization' encroaches on their lands and modern development and lifestyles overtake traditional cultures. We could be losing their priceless lessons before we can learn them.