From the San Francisco Chronicle:
Growing populations and expanding economic activity have strained the planet's ecosystems over the past half century, a trend that threatens international efforts to combat poverty and disease, a U.N.-sponsored study of the Earth's health warned on Wednesday.
The four-year, $24 million study — the largest-ever to show how people are changing their environment — found that humans had depleted 60 percent of the world's grasslands, forests, farmlands, rivers and lakes.
Unless nations adopt more eco-friendly policies, increased human demands for food, clean water and fuels could speed the disappearance of forests, fish and fresh water reserves and lead to more frequent disease outbreaks over the next 50 years, it said.
