JUDY WOODRUFF: If the climate change summit in Copenhagen looked to be just another chance for diplomats to talk, but get little done, today came a rallying cry from one of the top members of the U.S. delegation.
The head of the Environmental Protection Agency, Lisa Jackson, is in Denmark.
LISA JACKSON, administrator, Environmental Protection Agency: If we do not act to reduce greenhouse gases, the planet we leave to the next generation will be a very different place than the one we know today.
JUDY WOODRUFF: Other countries have gone out of their way to show the debate is urgent, the stakes high.
Leaders of the Maldives, a chain of islands in the Indian Ocean, staged a cabinet meeting under water to emphasize fears of rising sea levels that could literally wash away their nation.
Nepal's cabinet took to the frigid heights of Mount Everest to declare, the melting Himalayan glaciers pose a threat to them -- all this in the face of growing evidence from scientists that global warming risks more hurricanes, coastal flooding, forest fires, disease and massive population migration. The best way to head that off, they argue, is by reducing the amount of carbon humans spew into the atmosphere. But because that entails costly changes in the forms of energy used, there's no guarantee the 192 countries meeting these two weeks will reach a deal.
Already, major players, including the U.S., have begun to stake out their positions in Copenhagen. President Obama has pledged to cut overall U.S. emissions by 17 percent, relative to 2005 levels, by 2020. Today, he met privately with business leaders and environmentalists with a stake in the outcome.
TODD STERN, U.S. Special Envoy for Climate Change: There is a lot that is riding on this. And -- and I think there is a chance to do something very important here.
JUDY WOODRUFF: Todd Stern is the lead climate negotiator for the U.S. He says this summit is different from previous ones.
TODD STERN: Fundamentally, what is going on in this -- in this negotiation is an effort for the first time to have the major developing countries participate in the regime. That has not happened before. We are talking about those countries putting their own policies on the table in an international agreement, standing behind those policies, and having those policies significantly turn down their own emission curve.
JUDY WOODRUFF: In fact, Stern says success hangs especially on China's further cooperation, something now uncertain. Before the summit began, China, the world's largest polluter, pledged to voluntarily improve energy efficiency. India has made a similar pledge, but experts point out the total volume of carbon emissions for both would continue to rise, albeit at a slower rate. Shyam Saran is India's top climate negotiator.
SHYAM SARAN, Indian Special Envoy for Climate Change: We will try to push the envelope as much as we can and try to see that we get as good an outcome as is possible. I think there should be an appreciation of the fact that, despite being a developing country, despite having not very many resources available to us, we are actually spending very good money on many of these projects.
JUDY WOODRUFF: But even as pressure mounts on India and especially China, most look to the U.S. to take a leading role. The U.S. offer of carbon cuts comes with new money for developing nations. But other countries and environmentalists say the proposed emissions cuts are too small. Stern disagrees.
TODD STERN: By 2025, that number would go up to close to 30 percent. By 2030, it would be 42 percent reduction below 2005. And it would just march up from there. So, it's a very, very significant offer that we are putting on the table. This would really involve a seismic change in U.S. policy.
JUDY WOODRUFF: The proposed cuts in emissions match legislation approved by the U.S. House, but stalled in the Senate. And congressional approval of a global treaty is by no means assured.
SEN. JOHN BARRASSO, R-Wyo.: I have expectations that it is not going to accomplish the sorts of things that the organizers want. And I'm very pleased with that.
JUDY WOODRUFF: Republican Senator John Barrasso of Wyoming serves on the Senate Environment Committee. He is fighting the current climate bill, and is not supportive of an international agreement.
SEN. JOHN BARRASSO: My primary interest is to make sure that we as a nation don't handicap ourselves economically, at a time that, even if we did everything any environmentalist would want, that still wouldn't really have an impact globally on carbon emissions.
JUDY WOODRUFF: Opponents of a global deal are drawing attention to a recent scandal that some call climategate. E-mails between top scientists hacked from the computer of a British lab have raised serious allegations that researchers conspired to exaggerate and possibly manipulate the evidence of global warming. Researchers deny that, but the scandal has cast a cloud over the summit.
SEN. JOHN BARRASSO: I think there is great skepticism among people all across the country when they heard about these e-mails, this -- you know, this climategate. And they are saying, what's true here, and what's not true? So, I think people are very suspicious about this, and especially when you look at the kind of investment that the American people are being asked to make and the sacrifices, in the hopes of saving the planet 100 years from now.
TODD STERN: The underlying, the core reality here is, the science does not change, the science, because of this flap. I mean, there is science from all over the world that has established the basic sort of underlying realities, that the accumulation of greenhouse gases causes the Earth to warm, that the warming has a whole assortment of dangerous potential impacts.
JUDY WOODRUFF: President Obama will come to Copenhagen armed with evidence the U.S. is getting serious: an EPA declaration this week that carbon dioxide endangers human health, and must be regulated, even if Congress doesn't act. It's what environmentalists had wanted for years.
MIKE TIDWELL, executive director, Chesapeake Climate Action Network This refrigerator, as normal as it looks, uses the electricity equivalent of a 50-watt lightbulb. Activist Mike Tidwell of the Chesapeake Climate Action Network says a tough deal is what's required.
MIKE TIDWELL: This is a nation of laws. And, if we want to change this nation, we have to change laws, a la the civil rights movement.
JUDY WOODRUFF: Tidwell has limited his own carbon footprint. He drives a hybrid car, gets electricity from solar panels and heat from a corn-fueled stove. But he says that is not enough.
MIKE TIDWELL: So, individual changes count. They do raise awareness, but we will never solve the climate crisis one refrigerator at time, one household at a time. Instead of wagging our finger at Aunt Betty and say, go buy energy-efficient lightbulbs, wouldn't it be great if, the next time Aunt Betty went to buy lightbulbs, there were only energy-efficient lightbulbs? And you get there through policy and statute.
JUDY WOODRUFF: For that policy, Tidwell and others are pinning high hopes on Copenhagen.