Climate change, the rate of extinction of species and the challenge of feeding a growing population are putting humanity at risk, said the fourth Global Environment Outlook (GEO-4) report, the broadest environmental audit in 20 years.

While action has been successfully taken in some regions and on some problems, the overall picture is one of sloth and neglect, said the report by the UN Environment Programme (UNEP), which issued an 'urgent call to action'.

'The global trends on climate, on ozone, on indeed ecosystem degradation, fisheries, in the oceans, water supplies... are still pointing downwards,' UNEP head Achim Steiner said in a film accompanying the report's release on Thursday.

The report listed environmental issues by continent and by sector, offering an ominous view on how rapid human growth is stripping the earth of its resources but adding little of value in return.

In the Asia-Pacific region alone, increases in consumption and associated waste have contributed to the huge growth in existing environmental problems, it said.

These include degradation of urban air quality, fresh-water stress and illegal traffic in electronic and hazardous waste.

The 570-page report, the fourth in a series published by the UNEP, was compiled by nearly 390 experts from observations, studies and data garnered over two decades.

It offers the broadest and most detailed tableau of environmental change since the Brundtland Report, Our Common Future was issued in 1987 and put the environment on the world political map.

The GEO-4 report found progress in some areas since the 1987 report, such as a significant reduction of ozone-damaging chemicals. But it described as 'woefully inadequate' the global response to issues such as cutting emissions of carbon gases from power and transport.

It also noted that human activity has reached an unsustainable level, outstripping available resources.

Over the past two decades, the world population has increased by almost 34 per cent from 5 billion to 6.7 billion.

But each person in the world requires a third more land to supply his needs, exceeding the earth's capacity.

'The human population is now so large that the amount of resources needed to sustain it exceeds what is available at current consumption patterns,' said Mr Steiner.

GEO-4 outlined other global problems, including declining fish stocks and the loss of fertile land through degradation.

Environmental degradation also means that species are becoming extinct 100 times faster than fossil records show - with 12 per cent of birds, 23 per cent of mammals and over 30 per cent of amphibians facing extinction.

A separate report yesterday by the World Conservation Union's Primate Specialist Group noted that almost a third of all apes, monkeys and other primates now face extinction - notably the golden-headed langur of Vietnam and China's Hainan gibbon.

The GEO-4 report said that the earth has experienced five mass extinctions in 450 million years, the latest of which occurred 65 million years ago.

'A sixth major extinction is under way, this time caused by human behaviour,' it said.

Mr Steiner said: 'There have been enough wake-up calls since Brundtland. I sincerely hope GEO-4 is the final one.

'The systematic destruction of the earth's natural and nature-based resources has reached a point where the economic viability of economies is being challenged - and where the bill we hand on to our children may prove impossible to pay.'

AGENCE FRANCE-PRESSE, ASSOCIATED PRESS, REUTERS, NEW YORK TIMES