The economy could take a major hit if climate change continues at its current pace, according to the latest National Climate Assessment. NPR's Michel Martin speaks with climate scientist Michael Mann.
MICHEL MARTIN, HOST: We hope you had a wonderful holiday connecting with family and friends and perhaps doing a bit of traveling or shopping. Remarkably, a new government report suggests that all of those activities could be affected by climate change. The Fourth National Climate Assessment represents the work of 13 federal agencies. According to the report, if climate change continues at its current pace, the United States will suffer major economic losses from crop failures to severe disruptions to trade to major stress on critical infrastructure - even the possibility of large-scale migration within the U.S. The report also confirms that a wide range of disasters from wildfires and hurricanes to famine and disease are the product of human-made changes to the environment.</s>MICHEL MARTIN, HOST: We asked Michael Mann, a professor of atmospheric science at Pennsylvania State University, to speak with us about the report. And he's with us now from State College, Pa.</s>MICHEL MARTIN, HOST: Professor Mann, thank you so much for speaking with us.</s>MICHAEL MANN: Thanks. Good to be with you.</s>MICHEL MARTIN, HOST: How significant is this report?</s>MICHAEL MANN: I consider it quite significant. We've just lived through a summer - an unprecedented summer of weather extremes - droughts, wildfires, floods, superstorms. We are now seeing the impacts of climate change play out in real time. They're no longer subtle. And this report does a very good job in sort of putting meat on the bone - in providing the science behind what we can already see with our own two eyes - that dangerous climate change is already beginning to happen.</s>MICHEL MARTIN, HOST: The report says that the country's economic activity, the GDP, is actually going to shrink if the current policies aren't addressed, right? How does that actually happen? Like, what does that look like?</s>MICHAEL MANN: Climate change is impacting every sector of our lives and every sector of our economy. There's a huge national security cost. We have to defend the new coastline and Arctic coastline as the Arctic sea ice disappears. There's increased conflict around the world as a growing global population competes for less food and water and space. There is a real cost when it comes to agriculture. We've seen devastating impacts on the breadbasket of the United States - California, one of our most important agricultural states, that's been hit very hard by extreme heat and drought. The health care cost - people who are suffering the health consequences, whether it's infectious diseases or the impact of exposure to extreme heat. And you can go on down the list.</s>MICHAEL MANN: The cost of inaction is reaching into the tens of billions of dollars. And, as this report makes clear, we will be talking about hundreds of billions of dollars in the future. So what is now maybe a 1 percent tax on our economy from climate change impacts will become a 10 percent tax on our economy.</s>MICHEL MARTIN, HOST: Now, you may consider this to be outside of your wheelhouse, but the timing of the release is curious. The White House released it on Friday afternoon, the day after Thanksgiving. The former Vice President Al Gore views this as the administration trying to bury this news. On the other hand, the White House doesn't seem to have intervened in the report itself. What do you make of it?</s>MICHAEL MANN: Yeah. No, this isn't outside of my wheelhouse. In fact, I've written a whole book, "The Hockey Stick And The Climate Wars," about my experiences as a climate scientist under attack by politicians and fossil fuel industry groups. And Donald Trump has been a godsend to them. He has used the bully pulpit to attack the science of climate change almost on a daily basis. And he has appointed to his Cabinet fossil fuel lobbyists and climate change deniers who have done everything they can to literally dismantle the progress that we actually made in tackling climate change under previous administrations.</s>MICHAEL MANN: And this is the latest example trying to bury a climate report that they couldn't eliminate. It's congressionally mandated, so they had to put out the report. And they chose to try to bury it over a Thanksgiving weekend when, ironically, the fact that they were trying to bury this report has probably garnered a lot more attention for this report than we would've otherwise seen.</s>MICHEL MARTIN, HOST: Well, as you noted, the president has consistently pushed for environmental deregulation. And he tweeted just this week, whatever happened to global warming? Evidently, that was in response to the cold snap in the Northeast. On the other hand, the fact is that these 13 federal agencies did produce this extremely blunt report. And so the question that I then have is, is there a track on which progress can be made without executive leadership? Or is that just a fantasy?</s>MICHAEL MANN: No, absolutely there is. And, in fact, one of the sort of good pieces of news when you look at what's happening in the United States is that just based on what states are doing - individual states and cities and municipalities - and our largest companies who are all acting on climate change. It turns out that even without Trump's support we will still meet our obligations under the Paris accord. Most likely, you know, two years from now, we can obviously decide to elect a president who will build on the progress we are already making.</s>MICHEL MARTIN, HOST: That's Michael Mann, director of the Earth Systems Science Center at Pennsylvania State University. He was kind enough to talk to us.</s>MICHEL MARTIN, HOST: - Professor Mann, you so much for talking to us.</s>MICHAEL MANN: Thank you. It was a pleasure.