Biodiversity  Between 5 and 200 species disappear every day. Another figure sometimes quoted is 5 to 10 per hour. A million will supposedly have been made extinct by human activities by the year 2000.

Forests  In the tropics, these are being cut down at the rate of 17 million hectares per year (an area twice the size of Belgium) - 6% of the world’s total lost in the last 20 years. Tropical forests form a particularly ancient, rich and important ecosystem. Other types of forest are more replaceable: there is 30% more woodland today in Western Europe than 50 years ago. (However, much of this figure is accounted for by plantations of a single type of tree.)

Agriculture  35% of the earth’s surface is threatened by advancing deserts, due mainly to inadequate farming methods or destruction of the vegetation that protects the irreplaceable topsoil - 75 billion tonnes of which is lost a year, mainly in Africa and China. The inbreeding of wheat, rice and maize to provide one half of all the world’s food creates a genetic pattern called a monoculture, leading to increasing dependence on pesticides.

Energy  Global energy use increases by 2-3% a year - but a person in the West consumes 18 times more than someone in a "developing" country - some say that the average American consumes 510 times as many non-renewable resources as the average Himalayan villager. There are alternatives. Nuclear power, of course, brings with it a whole other set of risks - from the possibility of catastrophe due to human error or terrorist attack to the problem of radioactive waste.

Climate Carbon dioxide, methane and CFCs (chlorofluorocarbons) released into the atmosphere trap the sun’s heat to the tune of an extra 0.3°C per decade. The result is the gradual melting of the polar icecaps (with the release of large quantities of methane at present trapped in the Arctic permafrost), leading to flooding and unpredictable rainfall around the world. CFCs from refrigerators and aerosols have also destroyed part of the ozone layer in the upper atmosphere that protects the entire ecosystem against ultraviolet radiation.