AUDIE CORNISH, HOST:
The European Parliament approved the Paris agreement to reduce emissions of greenhouse gases around the world. It's a big milestone for the most ambitious agreement ever to rein in global warming. The U.S. and China and a long list of other countries were already onboard, so the vote in Europe today means enough nations have now signed on to allow the plan to go forward.
NPR's Christopher Joyce is here to talk more about it. And Chris, this agreement was drafted last December in Paris. What is the plan for how it will slow climate change?
CHRISTOPHER JOYCE, BYLINE: The basic goal is to keep the world's average temperature from going up more than two degrees Celsius - that's three and a half degrees Fahrenheit - above what it was before the Industrial Revolution. And if it does, scientists say we're in big trouble. And this is where sea level rise and massive drought and the other effects of climate change are really going to get a lot more serious than they have been so far.
And to do that, each country makes a voluntary pledge to do the best it can. And this agreement, unlike the previous agreements, includes all countries rich and poor, almost every country in the world.
CORNISH: Almost - right? - I mean this European vote today - it reached an important threshold.
JOYCE: It did. The Paris agreement was written such that it would not go into effect until at least 55 signatories, nations agreed and ratified it. And they had to represent over 55 percent of all the greenhouse gas emissions on the planet. And that happened, but nothing really is going to happen until the hard work is done, and that's what happens next.
The U.N. has to decide how to enforce this. They have to come up with rules on how to monitor nations to make sure they live up to their pledges. There's a hundred billion dollar a year fund that's supposed to come together by 2020. Rich countries are supposed to put that money up for developing countries to green-up their economies. And of course each country has to figure out how it's going to live up to this pledge. So all this is yet to be done.
CORNISH: What does that mean for the U.S.? What's the federal government here promising to do to reduce emissions?
JOYCE: The U.S. is already fairly far along the way. It's reduced its emissions already by about 10 percent over the last 15 years. But President Obama promised by 2025 that the U.S. would reduce its emissions by 26 to 28 percent below what they were in 2005. A lot of numbers there, but basically it's a 25 percent cut.
And you know, that's not going to be easy. The - part of the problem is the linchpin for that plan is a new regulation - the Clean Power Plan - which reduces emissions from coal-fired power plants. That's caught up in the courts. So how well the U.S. can live up to that is yet to be seen.
CORNISH: Plus of course we have an election going on. There could be a new president with different priorities.
JOYCE: We do have an election going on. (Inaudible).
CORNISH: You might have heard of it, yeah (laughter).
JOYCE: And there's quite a difference in the candidates because Hillary Clinton says she'll support the Paris Agreement, and Donald Trump says he would not. Officially, once you've signed on, you have to stick for four years. But you know, the U.N. doesn't have a police force to come and enforce that.
CORNISH: But to step back for a moment and look at the whole agreement, do we know it would actually work?
JOYCE: Oh, I don't know that anybody knows for sure. Eighty percent of the world's energy comes from fossil fuels. That is tremendous change in the world's energy economy that has come about. And research so far shows that these pledges, even if they're met under the Paris Agreement, are not going to keep us below two degrees. That's why the agreement requires people to come back every five years and renegotiate and try to ratchet the emissions down every five years.
That said, at least now there's an agreement that includes almost every country in the world, rich and poor, and they're all playing supposedly by the same rules.
CORNISH: That's NPR science correspondent Christopher Joyce. Chris, thanks so much.
JOYCE: You're welcome.