The speed at which mankind is using and abusing the Earth's resources is putting humanity's survival at risk, scientists have said.
The bleak assessment of the state of the environment globally was issued as an "urgent call for action" amid growing concerns of worldwide waste, neglect and governmental inertia.
Fundamental changes in political policy and individual lifestyles were demanded by the United Nations Environment Programme (UNEP) as it gave warning that the "point of no return" for the environment is fast being approached.
The damage being done was regarded by the UN programme as so serious that it said the time had come for the environment to be a central theme of policy-making instead of just a fringe issue, even though it would damage the vested interests of powerful industries.
Marion Cheatle, of the environment programme, said that damage sustained by the environment was of fundamental economic concern and, if left unchecked, would affect growth.
"The report provides incontrovertible evidence of unprecedented environmental change over the last 20 years that, unless checked, will fundamentally undermine economic development for current and future generations," she said as the report was released in London.
The report, the fourth Global Environment Outlook: environment for development (GEO-4), assessed the impact on the environment since 1987.
It was drafted on the basis of reports by almost 400 scientists, all experts in their fields, whose findings were subjected to review by another 1,000 scientists.
Climate change was identified as one of the most pressing problems but the condition of freshwater supplies, agricultural land and biodiversity were considered to be of equal concern.
It came 20 years after the publication Our Common Future by the Brundtland Commission, the first attempt by the UN to provide a comprehensive review of Man's impact on the environment.
The authors of the latest report said there had been progress on some environmental problems in the past two decades, most notably the international agreement to protect the ozone layer. But while maintaining that they wanted to avoid presenting a "dark and gloomy scneario", they concluded: "There are no major issues raised in Our Common Future for which the foreseeable trends are favourable."
They said the scale of the challenge was huge and highlighted a series of problems that need to be faced and tackled by people and governments around the world before damage to the environment becomes irreversible.
Increases in the world population, which has risen almost 34 per cent from 5 billion in 1987 to 6.7 billion today, have caused many of the challenges because of the demands on the Earth's natural resources.
Demand, heightened by a three-fold increase in trade since 1987, means that more is now being produced than can be sustained in the long term. On average, each person needs 21.9 hectares of the Earth's surface to supply their needs whereas, it was calculated, the Earth's biological capacity is 15.7 hectares per person.
The report was critical of the lack of action by governments in protecting the environment. The response to climate change was described as "woefully inadequate" but it was regarded as one of several significant problems that need to be addressed effectively.
"We appear to be living in an era in which the severity of environmental problems is increasing faster than our policy responses," it said. "To avoid the threat of catastrophic consequences in the future, we need new policy approaches to change the direction and magnitude of drivers of environmental change.
"The need couldn't be more urgent and the time couldn't be more opportune, with our enhanced understanding of the challenges we face, to act now to safeguard our own survival and that of future generations."
Overfishing was singled out as an issue that needed to be tackled as a priority. Measures to protect biodiversity, with species being forced into extinction at a rate 100 times faster than any in fossil records, were regarded as equally urgent.
Achim Steiner, executive director of UNEP, said that the international community's response to environmental issues was at times "courageous and inspiring", but all too often was inadequate.
"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 to our children may prove impossible to pay," he said.
Mike Childs, of the environmental campaign group Friends of the Earth, said: "The steady degradation of the world's environment threatens the well-being of everybody on the planet.
John Sauven, executive director of Greenpeace UK, said the report illustrated the importance of living sustainably: "It is the only way to improve global life expectancy and income inequality, beat climate change, reduce deforestation and protect biodiversity."
© 2007 The Times Online