Quotes of the Day

Global warming is a problem that spans the entire world, but when it comes to figuring out how to stop it, the burden will largely fall on two countries: the U.S. and China. The U.S. is the world's largest historic carbon emitter, responsible for putting more greenhouse gases into the atmosphere over the past century and a half than any other nation. China recently surpassed the U.S. as the current top emitter, and will be responsible for more greenhouse gases in the future than any other country. "These two countries hold the key to sustainability or catastrophe," says Jake Schmidt, the international climate policy director for the Natural Resources Defense Council (NRDC).

If that's the case, it might seem as if the world is headed towards catastrophe. Over the weekend, world leaders at the Asia-Pacific Economic Cooperation summit made explicit what had long been expected — that a legal, global treaty to reduce carbon emissions was no longer possible at next month's UN summit in Copenhagen. The deadlock between the U.S. and China is a big reason why: Beijing expects Washington to take the lead on cutting carbon, but the U.S won't sign onto a deal that doesn't including measurable action from the Chinese. From that perspective, climate change is one more competition between the world's reigning superpower and its number one challenger.

But the U.S.-China relationship is never as simple as it seems — and that includes climate change. The two countries signed a memorandum of understanding in July on enhanced cooperation on climate change, energy and the environment; and new Energy Secretary Steven Chu, whose parents hail from China, is reaching out to Chinese scientists. Major U.S. corporations, including the utility Duke Energy, have established joint projects with their Chinese counterparts on clean energy and low-carbon technology.

Most importantly, cooperation is beginning at the top: President Barack Obama's and Chinese President Hu Jintao put energy and climate change high on their agenda. "As the two largest consumers and producers of energy, there can be no solution to this challenge without the efforts of both China and the United States," said Obama in Beijing. "That is why we've agreed to a series of important new iniaitives in this area."

There are no agreements for specific numbers or emissions cuts at Obama and Hu's meeting. The White House has made it clear that the Senate must take the lead on setting emission levels, and China has been loath to name numbers for its own emissions. But the two Presidents did agree to establish a joint clean energy research center, supported by at least $150 million in funding over five years, a partnership on developing electric vehicles, a renewable energy roadmap and an action plan on energy efficiency. It fit the expectations of observers before the summit-broad cooperation on technology, but little specificity. "The big chance for cooperation is on technology," says Michael Levi, director of the program on energy security and climate change for the Council on Foreign Relations. "Early stage cooperation can help defuse some of the tensions of later stage technology transfer."

Despite being years apart in economic development, with U.S. per-capita carbon emissions nearly 10 times greater than Chinese levels, the two countries have similar concerns on energy. Both are major coal users, with half of U.S. electricity and 70% of Chinese energy derived from the carbon-intense fuel. Carbon capture and sequestration technology — where coal could be burned but carbon could be buried in the ground — is a perfect example of where the two countries' interests overlap, environmentally and economically. Indeed, Hu and Obama introduced a program called "21st Century Coal," to promote the development of large-scale clean coal programs, which included separate agreements among several Chinese and American companies on the issue.

Another area where the two countries can combine forces is in the development of a smart grid, which would marry electrical distribution to the intelligent networking power of the Internet. China has embarked on a vast expansion of its electrical grid, as it seeks to power its enormous manufacturing engine. At the same time the U.S. is slowly overhauling its own grid, turning it smart — the White House channeled over $3 billion to smart grid projects last month. The cooperation is natural. China is now the world's biggest industrial canvas, and it has a government willing to pay big money for big infrastructure projects. At the same time, the U.S. still has the lead on green innovation."Smart grid is going to happen and China is going to set the technical standards," says Jennifer Turner, director of the China Environment Forum at the Woodrow Wilson International Center for Scholars. "You have your Googles and your Ciscos, and they'll go to China because China sets the path for the development of clean technology."

Indeed, U.S. corporations like Duke Energy are going to China because the People's Republic is betting on a future of green tech, for better or for worse. The country already has some of the biggest manufacturers of solar panels and wind turbines. Though most of those products are exported to the West, China is emerging as a major consumer market for clean tech as well. It helps that Beijing, more than Washington, is willing to spend long-term on clean tech — China's green stimulus funding this past spring ran into the hundreds of billions. "U.S. companies are having considerable success in China," says Jonathan Lewis, the staff attorney and climate specialist for the Clean Air Task Force. "China has the institutional capacity, and it has the ready cash." (See pictures of the world's most polluted places.) There's a reason Chinese leaders have begun to focus on clean tech: after years of growing heedlessly, the nation of 1.3 billion is coming up against its ecological limits. Already a dry country, climate change could make China even drier, and glacial retreat in the Himalayas will negatively impact the country's major river systems. Without greater energy efficiency, China could bankrupt itself as it keeps growing — hence President Hu's pledge at the United Nations in September that the country would improve its carbon intensity over the coming years. "They realize they have to work with the U.S. to achieve their goals in this area," says Jonathan Adams, an associate in the climate and energy program at the World Resources Institute.

But for all the areas of potential cooperation and good feeling, there is still a need for firm negotiation between the U.S. and China — as there is in nearly every other aspect of their relationship. At some point, the two nations will have to sit down and figure out how to save the planet from the global warming that they, more than any other countries, have created. That didn't happen in Beijing this week — and it won't happen in Copenhagen in December for that matter. But it needs to happen soon. "This isn't like a Sputnik-style space race where one country wins and the other loses," says Barbara Finamore, China program director for NRDC. "They both stand to benefit." And if they don't, the whole world loses.

• Bryan Walsh
• At loggerheads over several issues, the senior and junior superpowers (and carbon producers) have lots of potential common ground on climate change