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How Healthy Is the Earth?

By Kathyrn R. Satterfield

After a four-year, $24 million checkup, the earth got a stern warning: Shape up. The message was not meant for the trees, birds or beasts. It was aimed at the people living on the planet.

The Millennium Ecosystem Assessment is the first global study to measure the health of the earth's ecosystems. An ecosystem is a community of plants, animals, other living things and their environment, functioning as a unit. More than 1,300 scientists and other experts from 95 countries worked together on the United Nations-sponsored report. The researchers studied thousands of satellite photos, analyzed statistics, interviewed business and government leaders and ran tests.

The report, which was released on March 30, says that growing populations and industry have hurt the planet's ecosystems. If nothing is done, increased human demand for food, clean water and fuels could speed the disappearance of forests, fish and freshwater supplies.

Walter Reid, the report's director, noted that over the past 50 years, humans have altered ecosystems more rapidly than during any other period in history. "These changes have resulted in a substantial and largely irreversible loss to the biological diversity of the planet," Reid says.

Turning the tide will require major changes. Conservation groups are calling on world leaders to consider the study's recommendations.

Stephen Carpenter, a scientist at the University of Wisconsin at Madison, worked on the report. He told TFK that even small-scale efforts within communities can reap big rewards: "We found that local problem solving, such as recycling, was very helpful. People working together is a good way to solve bigger environmental problems."

Next: Top 5 Largest National Forests in the U.S.