SCOTT SIMON, HOST:
This week, the United States and China agreed to reduce their greenhouse gas emissions. Advocates for action on climate change hailed the agreement as a huge step, but the deal is voluntary and the cost of meeting the goals will be high, which leads us to wonder how sturdy these commitments may be. We're joined now by NPR science correspondent Christopher Joyce.
Chris, thanks so much for being with us.
CHRISTOPHER JOYCE, BYLINE: Hi, Scott. It's a pleasure.
SIMON: Before we get into the prospects for this deal, what's on paper here?
JOYCE: The numbers are pretty straightforward. The U.S. has promised that it will reduce the emissions of greenhouse gases - this is carbon dioxide for the most part and other gases that warm the earth - and reduce them by 26 to 28 percent below what they were in 2005 - that's the baseline - and president Obama has said, we'll do it in 10 years from now.
As for China, it's somewhat easier. They don't have to reduce at all right now. What they have agreed to is they will sort of put their economy on a slow glide path where emissions will peak in 2030 and then start to drop and they also promised that they will endeavor to make sure that 20 percent of the electricity that they produce by 2030 will come from carbon-free sources like hydro, solar, wind and nuclear.
SIMON: And once again, remind ourselves now that the country is legally bound to follow this agreement, what's the track record for good intentions?
JOYCE: Very mixed. You know, it's interesting. If you look at, for example, domestic environmental laws in this country like the Clean Air Act and the Clean Water Act, there's a lot of stick there. If you don't comply, you get sued. They've worked reasonably well. You look at voluntary efforts - the clean-up of the Chesapeake Bay, for example, over the past 30 years, it's just accomplished very little because not only is there very little stick, but there are so many states involved there on the East Coast that watersheds' go into the Bay that they can't agree on what to do.
SIMON: Of course and international agreements involve even more governments. How have those efforts fared?
JOYCE: A lot depends on how much it costs and whether there's technology available. You take the ozone hole situation in the '80s, there was CFCs - chlorofluorocarbons, the chemicals in refrigerants - were poking a hole in the ozone layer, which is not good for the planet. Countries came together and very quickly resolved the problem. One reason it went fast was because there was technology, there were very few companies that were manufacturing them so that was fairly easy. You compare that, for example, with the Kyoto treaty to reduce climate warming emissions, that has not worked very well, in part because it's huge. You're talking about getting off of fossil fuels around the entire world. This is very expensive and the technology to do it really wasn't mature in the '90s. It's much more mature now, but still you're talking about a huge, huge job again and there's no enforcement mechanism really, to make it happen.
SIMON: Does this latest deal between the U.S. and China face a lot of those obstacles, as you suggested, as the Kyoto treaty?
JOYCE: Not exactly. Not really and I think that that's where there's some optimism here. You know, these are the two largest economies in the world. There's plenty of money to spend this. Furthermore, they're already part way along so even though it's voluntary, it's a lot easier than it would've been say, 20 or 25 years ago to do this.
SIMON: NPR science correspondent Christopher Joyce. Thanks so much.
JOYCE: You're welcome. Transcript provided by NPR, Copyright NPR.