U.S.-China deal a game-changer?

The United States, which remains the world's largest historical emitter of greenhouse gases, has now agreed to cut emissions by 26-28 percent of 2005 levels by 2025. In turn, China, which is currently the biggest emitter in aggregate terms, has pledged to reach peak emissions no later than 2030.

China's proposed target reflects the determination of Xi Jinping and Li Keqiang's leadership to contain climate change and tackle the difficult challenges and tradeoffs posed by the high levels of domestic air pollution caused by rapid industrialization, urbanization and reliance on fossil fuels.

However, the new targets are in line with China's transition from extensive growth based on investment and net exports to intensive growth characterized by consumption and innovation.

The United States' proposed target reflects popular opinion as defined by surveys and polls. In terms of aspirations, it is significantly more ambitious than President Obama's previous "U.S. Climate Action Plan," which he announced in Copenhagen half a decade ago.

However, the U.S.'s stated commitment will lead to a showdown with the newly-Republican-controlled Congress. Senate Minority Leader Mitch McConnell (R-Ky.) said after the deal that the bilateral pact signaled that the president "has no intention of moving towards the middle."

On Capitol Hill, things will only get more heated as Republican Senator James Inhofe, one of Congress's most prominent climate change skeptics, succeeds Democratic Senator Barbara Boxer as chair of the Environment and Public Works Committee in the Republican-led Senate next year. Inhofe has called the U.S.-China deal a "nonbinding charade" while promising to "do everything in [his] power to rein in and shed light on the Environmental Protection Agency's unchecked regulations."

But what will the U.S.-China deal mean in China?