Humans are responsible for the worst spate of extinctions since the dinosaurs and must make unprecedented extra efforts to reach a goal of slowing losses by 2010, a U.N. report said on Monday.
Habitats ranging from coral reefs to tropical rainforests face mounting threats, the Secretariat of the U.N. Convention on Biological Diversity said in the report, issued at the start of a March 20-31 U.N. meeting in Curitiba, Brazil.
"In effect, we are currently responsible for the sixth major extinction event in the history of earth, and the greatest since the dinosaurs disappeared, 65 million years ago," said the 92-page Global Biodiversity Outlook 2 report.
Apart from the disappearance of the dinosaurs, the other "Big Five" extinctions were about 205, 250, 375 and 440 million years ago. Scientists suspect that asteroid strikes, volcanic eruptions or sudden climate shifts may explain the five.