Reuters reports the latest threat posed by humanity
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.
The article states neither the documentation proving that mass extinction is indeed occurring, nor the evidence placing the primary blame on "[human-directed] habitat change, over-exploitation, the introduction of invasive alien species, nutrient loading and climate change."
Note this paragraph:
It estimated the current pace of extinctions was 1,000 times faster than historical rates, jeopardizing a global goal set at a 2002 U.N. summit in Johannesburg "to achieve, by 2010, a significant reduction in the current rate of biodiversity loss".
Nobody can identify historical rates of extinction, since nobody really knows how many species existed at any period in time.
The UN isn't exactly the first place I'd go to for advice on how to prevent extinctions.