Earth lacks the water, energy and agricultural land to allow China and India to attain Western living standards, a US think-tank has warned.

The Worldwatch Institute said the booming economies of China and India are "planetary powers that are shaping the global biosphere".

Its State of the World 2006 report said the two countries' high economic growth hid a reality of severe pollution.

It said the planet's resources could not keep pace with such growth.