Even as industrial civilization reaches into the farthest corners of the globe to extract resources such as oil, timber and fish, environmentalists are striving to mitigate its deleterious effects on the biosphere. Projects to reduce pollution, prevent climate change and protect biodiversity, however, are drawing criticism that they could drive indigenous people off their lands and destroy their livelihoods.

Conservationists have historically been at odds with the people who inhabit wildernesses. During the last half of the 20th century, millions of indigenous people in Africa, South America and Asia were ousted from their homelands to establish nature sanctuaries free of humans. Most succumbed to malnutrition, disease and exploitation, recounts anthropologist Michael Cernea of George Washington University. Such outcomes--coupled with the realization that indigenous groups usually help to stabilize ecosystems by, for instance, keeping fire or invasive weeds at bay--have convinced major conservation groups to take local human concerns into account. The World Wildlife Fund (WWF) now describes indigenous peoples as “natural allies,” and the Nature Conservancy pledges to seek their “free, informed and prior” consent to projects impacting their territories.