KELLY MCEVERS, HOST:
It's MORNING EDITION. I'm Kelly McEvers.
DAVID GREENE, HOST:
And I'm David Greene. Good morning. The world still has time to take action and reduce the effects of climate change, but time is running out. This is according to the latest report from an expert panel convened by the United Nations. The panel says that greenhouse gas emissions will need to drop dramatically in the coming decades and they lay out the options for doing that. NPR's Nell Greenfieldboyce has more.
NELL GREENFIELDBOYCE, BYLINE: Hundreds of experts from dozens of countries worked on this new report from the Intergovernmental Panel on Climate Change. Ottmar Edenhofer is a German economist who co-chaired the group that wrote it. He says scientists and government delegates had an intense meeting in Berlin to hammer out the language. At one point, he was negotiating for 28 hours non-stop.
OTTMAR EDENHOFER: So I have two espressos in the morning, two espressos in the afternoon, two espressos overnight and two more Cokes.
GREENFIELDBOYCE: The result of all that caffeinated negotiation is a document called "Climate Change 2014: Mitigation of Climate Change." It points out that emissions of greenhouse gases grew more quickly between 2000 and 2010 than in each of the previous three decades.
EDENHOFER: Emissions keep rising and we risk, for the second half of the century, unabated climate change and there is an increasing awareness around the globe that unabated climate change is a huge risk.
GREENFIELDBOYCE: Because of that risk, there's an international target to keeping the global temperature rise to just two degrees Celsius. That's 3.6 degrees Fahrenheit.
EDENHOFER: We are not saying that it is easy to achieve this. We say, under very specific circumstances, we can do this.
GREENFIELDBOYCE: Edenhofer says the report shows that it's still technically possible to limit the warming to two degrees Celsius, but greenhouse gas emissions would have to drop 40 to 70 percent by 2050 and then drop even more, to nearly zero by the end of this century. Doing that would mean a huge shift towards energy sources like wind, solar or nuclear power, plus a slew of other changes, like increasing the energy efficiency of buildings and slowing deforestation.
ROBERT STAVINS: That's not going to happen on its own. Public policies are going to be required. That's the key message.
GREENFIELDBOYCE: Robert Stavins of Harvard University is an economist and expert on climate agreements who worked on the report. He says one issue raised in the report is the idea of geo-engineering, using new technologies to suck carbon dioxide from the atmosphere.
STAVINS: It's quite controversial. It's controversial among environmental advocates, it's controversial among scientists, and it's certainly controversial among governments, but research is clearly needed.
GREENFIELDBOYCE: A central theme of this report is that timing is critical. Jennifer Morgan is director of the climate and energy programs at the World Resources Institute in Washington, D.C. She was a reviewer for one of the reports chapters.
JENNIFER MORGAN: What this report means is that there are very key choices for governments and business and citizens to make, and that the timing of action is absolutely vital. If we wait, we will close off opportunities to avoid the impacts and we'll make it a lot more expensive.
GREENFIELDBOYCE: She says the international community is getting ready to negotiate a new climate change agreement next year, under the United Nations Framework Convention on Climate Change.
MORGAN: Every country in the world by the first quarter of 2015 have to put an offer on the table to the rest of the world about what they're going to do to tackle the problem.
GREENFIELDBOYCE: Morgan says this report gives them all the tools they'll need to do that. Nell Greenfieldboyce, NPR News.