Planet at a crossroads.

• Position: Global Environment Outlook-3

Over 70 per cent of the Earth's land surface could be affected by the impacts of roads, mining, cities and other infrastructure developments in the next thirty years unless urgent action is taken, according to the Global Environment Outlook-3 (GEO-3) report of the UN Environment Programme (UNEP). Over 1,000 people, many from a global network of collaborating centres, contributed to the preparation of GEO-3. It says the planet is at a crucial crossroads, with the choices made today critical to the forests, oceans, rivers, mountains, wildlife and other life support systems upon which current and future generations depend.

Calling GEO-3 "the most authoritative assessment of where we have been, where we have reached and where we are likely to go", UNEP Executive Director Klaus Toepfer stressed that the facts in the report underlined "the huge amount of knowledge that has now been accumulated about the condition of Earth". Highlighting the successes of Governments, industry, the public and others in trying to restore and sustain its damaged and beleaguered freshwaters, lands, wildlife, oceans and atmosphere, the study takes a unique look at the policies and environmental impacts of the past thirty years. It outlines four policy approaches for the next three decades (See "Future Choices" on page 46), and compares and contrasts the likely impacts on people and the natural world.

More than half the population in the world could be living in severely water-stressed areas by 2032 if market forces drive the global political, economic and social agenda. West Asia, which includes the Arabian Peninsula, is likely to be the worst affected with well over 90 per cent of the population expected to be living in areas with "severe water stress" by 2032. Habitat disturbance and other kinds of environmental damage as a result of rapid and poorly planned infrastructure growth will most likely affect Latin America and the Caribbean region with more than 80 per cent of the land affected, followed closely by Asia and the Pacific, with over 75 per cent.

Concerted action involving Governments and industries could also deliver deep cuts in emissions of gases linked with global warming. With sufficient public and private will, levels of carbon dioxide could begin stabilizing in the atmosphere by 2032. Improvements have occurred in areas such as river and air quality in North America and Europe. The international effort to repair the ozone layer--the Earth's protective shield--by reducing the production and consumption of chlorofluorocarbons (CFCs) is another notable success.

Generally, however, there has been a steady decline in the environment, especially across large parts of the developing world. The declining environmental quality and the apparent increase in strength and frequency of natural hazards such as cyclones, floods and droughts are intensifying peoples' vulnerability to food insecurity, ill health and unsustainable livelihoods, says the report.

Behind nearly all the...