A productive, but taxed, Earth
A UN-sponsored study finds that humans' growing demands have damaged the planet at unprecedented levels.
For hundreds of years, cod swarmed in waters off Newfoundland's rugged coast. But by 1992, rampant overfishing had crushed the cod. Price tag to people: tens of thousands of jobs lost and billions of dollars spent in job retraining.
Last year, a weather satellite spotted a monster dust cloud over Africa - hard to miss at 5,000 miles wide. Tree-cutting in northern Africa helps nourish such clouds, which cross the Atlantic, settle into US coastal waters, and possibly contribute to toxic algae blooms. Price tag to people: breathing problems for US coastal residents.
Cod depletion and dust clouds seem like pretty different problems. But they each play a role in the overall environmental degradation of the planet - a condition that a new global study says has escalated so quickly over the past 50 years that it outpaces anything experienced by ecosystems in human history.
Demands for water, food, fuel, timber, and fiber - all part of global economic expansion - have driven the change. The result: a big increase in short-term human benefits, less hunger, and more wealth. But this progress has been counterbalanced by a massive loss of diversity of life on Earth.
That's the state of the world, according to the first Millennium Ecosystem Assessment produced by some 1,300 scientists from 95 countries charged with painting a global eco-portrait. The United Nations-sponsored study was funded by the World Bank and several private foundations.
"We've had many reports on environmental degradation, but for the first time we're now able to draw connections between ecosystem services and human well-being," says Cristian Samper, director of the Smithsonian Institution's National Museum of Natural History in Washington and a chief architect of the study.
Northern Africa's drying Sahel region and Newfoundland's emptier coastal waters, he says, are just two examples in an overall conclusion that 60 percent of the world's ecosystems are being degraded or used unsustainably. Ecosystems being drained or degraded largely in the pursuit of human well being include:
• Land: More of it has been converted to crop land since 1945 than in the 18th and 19th centuries combined. Cultivated land now covers one-quarter of Earth's land surface.