“This is a major milestone in the U.S.-China relationship,” Obama said at a news conference with Xi in Beijing. The two nations, which account for more than a third of greenhouse-gas emissions, have a “special responsibility” to lead efforts to address climate change, he said.

The climate deal capped two days of meetings and announcements of deals that Obama and Xi said marked a high point for U.S.-China cooperation. Officials from both countries also negotiated a breakthrough in talks to eliminate tariffs on communications and technology products from printer cartridges to magnetic-resonance imaging machines, vowed greater military coordination and extended the validity of visas for tourists and business travelers.

Obama is setting a new target for the U.S., agreeing to cut greenhouse gas emissions to 26 to 28 percent below 2005 levels by 2025. The current U.S. target is to reach a level of 17 percent below 2005 emissions by 2020.

China’s Commitments

Xi committed China to begin reducing its carbon dioxide emissions, which have risen steadily, by about 2030, with the intention of trying to reach the goal sooner, according to a statement released by the White House.

China, the world’s largest greenhouse-gas emitter, also agreed to increase its non-fossil fuel share of energy production to about 20 percent by 2030, according to the White House.

Obama called the plan “an ambitious but an achievable goal.”

The agreement may signal an opening to the new relationship that both leaders said they sought after being at odds over computer hacking attacks that federal law enforcement officials suspect originated in China, territorial disputes involving two U.S. allies and probes by Chinese prosecutors of American companies such as Microsoft Corp.

Personal Involvement

Obama and Xi were personally involved in the discussions. Obama sent Xi a letter on the matter this year, according to administration officials, and the topic was a central theme during the more than five hours of meetings last night in Beijing after the Asia-Pacific Economic Cooperation summit.

One outcome may be fresh momentum for international negotiators in advance of the 2015 United Nations climate conference in Paris.

“These are big emitters, and these are very aggressive targets,” Martijn Wilder, head of global environmental markets at law firm Baker McKenzie, said today by phone from Sydney. “This makes it very difficult for other countries to say we’re not going to do anything.”

European Union Parliament President Martin Schulz said the announcement shows that the drive toward the UN climate talks is “clearly growing.”

Big Impact

Jake Schmidt, director of international programs for the Natural Resources Defense Council, a Washington-based environmental group, said no other countries can have as big an impact on theclimate debate as the U.S. and China.

“They shape how the market invests,” he said. “They’ve also been two of the most difficult players in the history of the climate negotiations so the fact that they are coming out and saying they are going to take deep commitments will be a powerful signal to the rest of the world.”

Obama, at a UN-sponsored climate meeting in New York in September, called on the more than 120 officials present to take action “not this year, or the year after, but right now, because no nation can meet this global threat alone.”

Chinese officials signaled at the same summit that the country would act on a carbon-dioxide cap soon. China has been taking steps to cut emissions, saying in September it plans to start a national carbon-trading market by 2016. China selected seven cities and provinces, including Shanghai, Beijing and Guangdong, to set regional caps and institute pilot programs for trading rights as part of its initiative to cut emissions by as much as 45 percent before 2020 from 2005 levels.

China’s Pollution

China has domestic political reasons to pursue emissions cuts. Pollution in Beijing reached hazardous levels for at least 10 days in October. To cut the haze while leaders from APEC nations were in Beijing, the government put limits on the number of cars on the roads and restricted industrial production and construction.

Obama has made climate change a central issue for his final two years in office, though his agenda is under attack by Republicans, who are set to take control of both chambers of Congress at the start of next year.

The administration officials, who briefed reporters before the announcement on condition of anonymity, said the new targets can be implemented without congressional action.

Republicans, who won control of the U.S. Senate in midterm elections on Nov. 4, are threatening to fight the administration’s efforts to cut greenhouse-gas emissions from U.S. power plants and his pledge to raise $100 billion to help poor nations combat climate change.

Copyright 2014 Bloomberg

Lead image: China and US handshake via Shutterstock