In announcing his new national climate action plan, President Obama told students at Georgetown University, "I refuse to condemn your generation and future generations to a planet that is beyond fixing."
The plan faces strong opposition in Washington, but Joanna Lewis, who teaches science, technology and international affairs at Georgetown, says it's likely to get a much warmer reception outside the country.
Arguably the biggest and most far-reaching story that we're covering here at The World is climate change.
And right now we're talking and hearing a lot about climate change as part of our "What's for Lunch" series on climate and food.
The two are deeply linked, as we've been hearing in several recent stories.
Well, today, President Obama jumped back into the conversation on climate change in a big way–talking not about food, but about energy.
"I refuse to condemn your generation and future generations to a planet that is beyond fixing," Obama told students in a much-anticipated address at Georgetown University in Washington.
"And that's why today I'm announcing a new national climate action plan. And I'm here to enlist your generation's help in keeping the United States of America a leader, a global leader, in the fight against climate change."
The president pledged specific measures to meet his 2009 goal of cutting greenhouse gas pollution in the US by 17 percent from 2005 levels by 2020.
It includes a plan to regulate carbon emissions from existing power plants, which likely means big cuts in the use of coal.
It also promises new energy efficiency standards for trucks, buildings and appliances.
The president also vowed to work more closely with other countries on cutting their emissions.
Here in the US, the political battles over Obama's plan have already begun. But it's likely to get a much warmer reception outside the country.
We spoke with Joanna Lewis, who teaches Science, Technology and International Affairs at Georgetown and is a member of the UN's Intergovernmental Panel on Climate Change.
She says the announcement will be very important internationally.
"The entire world was listening, and I think this is really going to help push the international negotiations forward," Lewis said.
"China and the United States are of course the largest emitters of greenhouse gases, and we've already seen some real concrete action from China with the launch of several new pilot carbon dioxide trading programs. And China's working toward implementing a national carbon trading program.
"So I think the world has been waiting for an announcement from the United States to see how they were going to move forward in reducing their own emissions and meet the target that they've already pledged internationally."
So if everything in Obama's plan is implemented, where would the US sit in terms of its carbon emissions compared to other major economies?
"The US is still by far the largest industrialized emitter of carbon dioxide in the world, " Lewis said, "so even if it meets its climate targets it's still going to be a very large emitter.
"But I think that's exactly why the US needs to play this leadership role. One of the main reasons the international negotiations have lagged in recent years is because many had hoped to see much more aggressive action from the United States once President Obama entered the While House back in 2009. And this is really the first high-profile announcement we've heard from the President on climate change, so I think this really sets the mood and puts climate change back on the agenda for the second term.
"And the timing is really good for the international process, because the world is currently working to come up with a new international climate agreement to follow on the Kyoto Protocol by 2015. So time is of the essence, and they're really working with a rapid timetable."
A big part of the emphasis in Obama's speech was on coal–either significantly reducing its use or requiring that it be burned more cleanly. But coal consumption is already falling dramatically here in the US, while it's growing like gangbusters in other parts of the world–places like China, India, even parts of Europe.
So how much would the President's plan really help change coal emissions on a global scale?
A lot, Lewis said.
"Even with the resurgence we've seen in natural gas use in the United States in the last couple of years, we've actually seen a relatively new increase in the use of coal plants for the first time in several years. So I think it's going to be extremely important that the new power plant regulations start to curb the growth of new coal plants in the United States. We have a lot of opportunities to continue to use natural gas as well as to promote the use of much more renewable energy than we are.
"And of course while countries like China and India are going to continue to build coal plants, even in those countries they're trying to diversify away from coal. China, in fact, has a cap on national coal consumption that they're trying to implement in the next five years."
So will Obama's plan have any impact on the growth of the use of coal globally?
Hard to say, Lewis says.
"If the United States can signal to the rest of the world that it's going to move away from using coal for electricity, this will send a very strong message even to the emerging economies about the continued use of coal in their power system."