NOEL KING, HOST:
What has the president's decision to leave the Paris Agreement meant for climate science? Rebecca Hersher is with NPR's climate science team. Good morning, Becky.
REBECCA HERSHER, BYLINE: Good morning.
KING: So we have this agreement that the U.S. is now out of, but 200 other countries are still in it. How is humanity broadly doing on carbon emissions?
HERSHER: Well, humanity broadly is not doing great. When you look at the hard numbers that scientists look at, it's bad. Global emissions are still going up, which is a nightmare if you study global warming because the Earth is already about 2 degrees Fahrenheit hotter than it was last century. So humans are on track for catastrophic warming in the next few decades.
KING: OK. How is the U.S. specifically doing?
HERSHER: Well, to answer that, I want to go back a little bit. So if you add up all the CO2 and other carbon that countries have spouted since industrialization, the U.S. has emitted the most. And I think that's really important because the U.S. emissions have been going down slightly for a while now, but they've never fallen really dramatically. And that's different from European countries, which also emitted a lot of carbon historically but have slashed their emissions in the last few decades.
KING: So there's another piece of context here that is really important, which is that President Trump announced 3 1/2 years ago that he was going to pull the U.S. out of this agreement. Today - you know, in November, it'll be official, but in the meantime, in those 3 1/2 years, have his administration's policies led to more climate emissions?
HERSHER: It's a good question. It's hard to be definitive, but here's what scientists say - it probably made a difference. So the U.S. promised under the Paris Agreement to reduce emissions by about 25% by 2025. Most analysts say that if the policies of the Obama administration, things like limits on emissions from cars and trucks and power plants, if those had continued for the last four years, the country would likely be on track for that goal. Instead, the U.S. seems to be looking at more like a 16% or 17% decrease in emissions.
KING: Which is not insignificant. How is the U.S. on track to reduce emissions by 16%, 17% if the federal government and its policies are working in the opposite direction?
HERSHER: Right. I think that's a really interesting question. So one thing is that the global economy is changing. Renewable energy is getting cheaper. The market for electric vehicles is growing. So that cuts some emissions right off the bat. And more than half of U.S. states say they're trying to meet the 25% goal that the U.S. originally set under the Paris Agreement. And especially in the last year, there's been a huge movement by corporations promising to decarbonize their operations. And that's become a really big question in the science community where they're trying to model future warming and asking this interesting question, which is, what will be the main driver of emissions reductions in the next 10 years? Will it actually be national policies, so things we tend to focus on with the Paris Agreement, or will it be corporate policies, state policies, even city policies?
KING: Oh, I bet the answers to that will be interesting. And let me ask you lastly - say Joe Biden does win the election. Could he put the U.S. back in the Paris climate agreement?
HERSHER: Yes, yes. So as we said, we'll be formally out the day after the election. If President Trump wins a second term, the U.S. will remain out of the agreement. U.S. emissions will fall slowly. If Joe Biden wins, he has said he will re-enter. He can do that as soon as he takes office if he wins. The bigger thing would be trying to work with Congress to pass new renewable energy and transportation policies. And that would have to happen pretty quickly to avoid the most catastrophic warming.
KING: Rebecca Hersher with NPR's climate team. Thanks, Becky.
HERSHER: Thanks so much.
(SOUNDBITE OF EMANCIPATOR'S "BLUE DREAM") Transcript provided by NPR, Copyright NPR.
