A troubling new United Nations report foreshadows mass extinctions if humans fail to take major action on climate change in the next few years. One million of the planet’s 8 million species are threatened, which could have devastating consequences for the rest of us. What can, and what should the United States be doing to make changes?

In for Jim Braude, Adam Reilly was joined by David Cash, dean of UMass Boston’s School of Policy and Global Studies and former Massachusetts commissioner of the department of environmental protections; and Anthony Janetos, director of the Pardee Center for the Study of the Longer Range Future and chair of the Department of Earth and Environment at Boston University.