Most World Ecosystems Overtaxed, Study Warns

by J.R. Pegg

(ENS) WASHINGTON -- Human activities are rapidly changing the Earth's natural environment and threaten the planet's capacity to support future generations, according to the most comprehensive analysis ever conducted of the world's ecosystems.

The stark warning is the conclusion of more than 1,300 scientists from 95 countries, who found that 60 percent of the ecological systems that support life on Earth are being degraded or used unsustainably.

"The warning signs are there for all of us to see," said the 45-member board of directors of the Millennium Ecosystem Assessment (MA). "Human activity is putting such strain on the natural functions of Earth that the ability of the planet's ecosystems to sustain future generations can no longer be taken for granted."

The MA is a four-year project that included scientists from the United Nations, international scientific organizations, universities as well as private sector and civil society groups.

It is supported by 22 of the world's leading scientific bodies, including The Royal Society of the UK and the Third World Academy of Sciences.

Released March 30, the MA Synthesis Report is the first in a series of seven reports that assess the state of global ecosystems and their impact on human wellbeing.

It concludes ecological degradation is a major roadblock to efforts to address poverty, hunger and public health and will not be reversed unless there is decisive and comprehensive action by world leaders.

The study found ecological damage has accelerated tremendously in the past century and much of the degradation has occurred in the past 50 years, as society has acquired the food, fresh water, energy and materials needed to support the world's increasing population.

More land was converted to agriculture since 1945 than in the 18th and 19th centuries combined, the study says, and nearly a quarter of the Earth is now cultivated.

Water withdrawals from lakes and rivers for human use have doubled in the past 40 years and a third of the world's population lives within ecosystems that contain less than 10 percent of the global freshwater supply.

The flow of nitrogen into the oceans has doubled since 1860 and at least 25 percent of marine fish stocks are overexploited.

The accelerated and sustained resource exploitation of the past 50 years has opened the door to new diseases, widespread water pollution, coastal dead zones and the likely collapse of some global fisheries, the report concludes.

The report determined that 15 of 24 "ecosystem services" that support life on Earth are suffering from ongoing degradation.

Only four have been enhanced in the past half-century -- crop, livestock and aquaculture production, as well as increased carbon sequestration.

Two services, capture fisheries and fresh water, are now well beyond levels that can sustain current, much less future, demands and the report concludes these problems will substantially diminish the benefits for future generations.

Increased resource exploitation and changing land use over the past century has resulted in a substantial and largely irreversible loss in biodiversity, the report concludes.

Some 10 to 30 percent of the mammal, bird and amphibian species are currently threatened with extinction.

The report details how the world's poorest people suffer most from ecosystem changes, in particular access to clean water.

And many of the regions facing serious ecosystem degradation -- such as sub-Saharan Africa, Central Asia and parts of Latin America and South Asia -- also face problems of severe poverty and projected population growth, according to the study.

The MA board warns that global climate change has "the greatest potential to alter the natural infrastructure of the Earth" and calls for "radical changes" in how nature is treated at every level of decision-making.

Society must erase the "dangerous illusions that ignore the vast benefits of nature to the lives of the 6 billion people on the planet," the board said. "We may have distanced ourselves from nature but we rely completely on the services it delivers."

The study also calls for greater involvement of local communities in efforts to conserve resources.

"This need not be a counsel of despair," the MA board said. "The natural balance sheet we bequeath to future generations depend on choices made at every level and in every corner of the planet É the future now lies in our hands."

UN Secretary General Kofi Annan called the report "an unprecedented contribution to our global mission for development, sustainability and peace."

"Only by understanding the environment and how it works, can we make the necessary decisions to protect it," Annan said. "Only by valuing all our precious natural and human resources can we hope to build a sustainable future."