Study says Earth on brink of mass extinction event

June 18 - A landmark study by an international group of scientists has concluded that planet Earth is on the brink of a mass extinction event comparable in scale to the one that wiped out the dinosaurs 65 million years ago. The researchers found that extinction rates are currently 1000 times higher than normal due to deforestation, global climate change, and the depletion of ocean fisheries. Ben Gruber reports.