Submitted by Stix: Changes to Earth's biodiversity have occurred more rapidly in the past 50 years than at any time in human history, creating a species loss greater than anything since a major asteroid impact wiped out the dinosaurs. That's the conclusion of Global Biodiversity Outlook 2, a report released today by the United Nation's Convention on Biological Diversity."In effect, we are currently responsible for the sixth major extinction event in the history of the Earth, and the greatest since the dinosaurs disappeared, 65 million years ago," the report states.The wide-ranging report also states that demand for resources globally exceeds the biological capacity of the Earth by some 20 percent. "Two thirds of the services provided by nature to humankind are in decline, worldwide," said Ahmed Djoghlaf, Executive Secretary of the U.N.'s Convention on Biological Diversity, in an open letter to all of the planet's citizens. "Humans have made unprecedented changes to ecosystems in recent decades to meet growing demands for food and other ecosystems services."The report offers simple economic logic for maintaining biodiversity: "Biodiversity loss disrupts ecosystem functions, making ecosystems more vulnerable to shocks and disturbances, less resilient, and less able to supply humans with needed services."Biodiversity loss has "weakened nature's ability to deliver its vital services," Djoghlaf writes. "Human activity is putting such strain on the natural functions of Earth that the ability of the planet's ecosystems to sustain future generations can no longer be taken for granted."