According to the latest report from the World Wildlife Fund, global wildlife populations have declined by a whopping 69 percent over the past 50 years. It's an urgent reminder of what's at stake as world leaders prepare to meet in early December for their biggest biodiversity conference in a decade, with the goal of agreeing to a new framework to protect the world's plants and animals. According to scientist Paul Leadley, the new framework contains all the measures needed to reverse the damage – but world leaders must be convinced to adopt it. Leadley is one of the main contributors to the UN's Intergovernmental Panel on Climate Change (IPCC). He joined us for Perspective.