Science Ahead of Rio +20 summit, UN sounds environmental alarm (+video)

A UN report released ahead of an environmental summit in Brazil warns that overpopulation, urbanization, and consumption pose grave threats to the Earth's biosphere.

Ueslei Marcelino/Reuters

Population growth, urbanization and consumption are set to inflict irreversible damage on the planet, the United Nations said on Wednesday, and called for urgent agreement on new environmental targets at an Earth summit this month.