Dr. Michael Mann: Last 8 years were ‘warmest’ on record, but we can still avert 'worst consequences’

Director of the University of Pennsylvania Center for Science and Sustainability and author of “The New Climate War” Dr. Michael Mann joins Andrea Mitchell to weigh in on the state of the climate crisis and what can be done to slow warming. “The last eight years are the warmest eight years on record,” says Dr. Mann. “As soon as we stop putting carbon pollution into the atmosphere, the planet stops warming up and these impacts stopped getting worse. So that's what our focus has to be: getting down to 50% reduction this decade, and net emissions down to zero by mid century. If we can do that, we prevent warming of 3º Fahrenheit, we prevent the worst consequences.”