KELLY MCEVERS, HOST:
Another focus of this week's summit with the Chinese president has been climate, specifically what the U.S. and China can do to limit greenhouse gases that are warming the planet. NPR's science correspondent Christopher Joyce has been following that part of the story, and he joins us now in the studio. And Chris, what came out of these climate discussions between President Xi Jinping and President Obama?
CHRISTOPHER JOYCE, BYLINE: It's a joint statement between the two presidents - essentially a handshake - in which they agreed to reduce emissions of greenhouse gases in both their countries. But it's also a geopolitical signal to the world as the nations of the world gather together at the end of the year to come up with a new climate treaty. They are together, and the U.S. and China are basically doing the same shake. And so what else is everybody going to do?
MCEVERS: And so on the first issue of reducing emissions - I mean, didn't they already agree to that last fall?
JOYCE: They did, and this was a big deal then because China said, finally, look; we're going to set a target. We're going to peak our emissions. In other words, we'll let them go up, but they will peak in 2030. We're also going to try to get a fifth of our electricity from renewable sources. It was quite a commitment.
And the U.S. came up with some of its own plans. President Obama promised to reduce emissions from coal-fired power plants under the so-called Clean Power Plan. And so it was a big item. But what's happened now is that China has sort of gone beyond that now and particularly with something called a cap-and-trade program.
MCEVERS: Right. And that is essentially a market where companies buy and sell permits that allow them to emit greenhouse gases, right?
JOYCE: That's right, yeah. I mean, there's one in California. There's one on the Eastern states. Europe has been doing it for 10 years. The way it works is, a state - in California - or a nation or a group of nations, as in Europe - they set a top limit for an industry, like a - like, say, power plants. And they say, OK, this is the cap for the whole country. And then they give each power plant permits to emit greenhouse gases.
JOYCE: And you add them up, and they come to the cap. So if you're a company that puts money into reducing emissions and being more efficient, you got extra permits you can sell, and a company that can't can buy them. And so, you know, it gives industry a chance - some wiggle room to - if they can't really get their emissions down of the first year or the second - and the cap keeps coming down year after year - they get a chance to buy and sell the right to pollute. Some people don't like this.
MCEVERS: Right, including the pope.
JOYCE: The pope does not like it. In the encyclical, he said, you know, the market mechanism is not the right way to do this. I mean, he looks at it from a more moral point of view. There are some environmental groups that don't like it, but a lot do. In fact, the whole idea was sort of invented by environmental groups in the U.S.
MCEVERS: Besides cap and trade, what else is China offering here?
JOYCE: There's a collection of promises. Both countries are going to target heavy-duty trucks. They're going to bring emissions down in new buildings and try to get new buildings to use less electricity. Again, they keep piling these things on, and when you had them all up, they bring emissions down.
MCEVERS: Is there a reason that the U.S. and China seem to be now making these promises together?
JOYCE: Yes, indeed. It's very geopolitical. The conference in Paris, the next big climate conference, is kind of like the last chance to replace the one that was signed in 1997 - the Kyoto Protocol.
JOYCE: They've tried for years and failed for years to come up with a new plan. The Paris approach is very different. This is not our parents' - or some people's parents' - climate deal like it was in '97. Everybody has to participate, including developing countries. And China and the U.S. are presenting themselves as, like, the two biggest economies now.
China is going to play. China wants to do more than play. They want to sort of be the defender of the developing world they're coming up with their own $3.1 billion pledge to help the developing world adapt to climate change, which tops the U.S. offer by point-one. And so this is a message to many countries, especially India and Indonesia and Brazil, the other big emitters, OK, China and the U.S. - they're together on this; what do you guys got?
MCEVERS: You know, it's interesting thinking about this moment for climate change. And the pope, I mean, he's really resonating with people. I mean, this is something scientists have been trying to do for a long time, right?
JOYCE: It's ironic because scientists have had a difficulty in convincing a lot of people in the United States. The remaining numbers who were deniers or skeptics or whatever you want to call them - and there is a certain irony in the fact that the many are hoping that the pope can convince people when scientists could not.
MCEVERS: NPR's science correspondent, Chris Joyce, thanks so much.
JOYCE: My pleasure. Transcript provided by NPR, Copyright NPR.