Within a Sky Full of Earth

Concern over the world's booming human population - which has grown from three to over six billion in just 40 years - has abated somewhat as birth rates have fallen right across the world. But there is still a long way to go before numbers stabilise at somewhere between eight and 11 billion - and some countries, such as Pakistan or Nigeria, are on course to triple their numbers by the middle of this 21st century.

Globally, many experts are concerned that the earth's 'carrying capacity' is already overstrained, and worry that the huge impending increases in consumption in countries such as India and China will add enormously to the burden of greenhouse gases which threaten to heat the planet - not to mention all the other demands which increases in both population and consumption are putting on the earth's natural systems.