China is serious about climate change.

China had already signaled it would tackle air pollution and greenhouse gas emissions, with initiatives like launching a national market for trading carbon permits and promising to make Beijing coal-free by 2020. Experts like Jake Schmidt, director of the International Program at the Natural Resources Defense Council, just weren’t sure how much it was ready to commit to. “A couple of years ago, if anybody had said that China will have its C02 peak in 2030, it would have sounded unrealistic,” Schmidt said in an interview. “Most analysts back then were talking about 2040 or much later.”

Republicans have long used China’s growing emissions as a reason why the U.S. should do nothing. For instance, Senator Marco Rubio argued in 2013 that as “a country, not a planet,” U.S. action would have “a very negligible impact on the environment […] China, India, and others — they’re now the largest polluters in the world by far.” (A Climate Desk video compiles more of these excuses). China could just as easily point out that the U.S. was not doing enough as the world’s biggest polluter historically. This deal undercuts a favorite Republican excuse for sitting out of a global climate change agreement.

Obama has more planned.

Obama’s target would double the average pace of carbon cuts from 2005 to 2020, now at 1.2 percent per year, to 2.8 percent. According to the White House, the 26-28 percent cuts can be done under existing law. But the reality is that reaching these cuts requires commitment from both this White House, and the next one. Of course, this is assuming that the Environmental Protection Agency’s proposals to cap power plant emissions remain intact, despite Republican opposition. There are at least two sectors these cuts could come from: the transportation sector, which hasn’t seen demand rise since 2005, and in the power sector, by strengthening the EPA's plan for carbon cuts from coal-fired power plants and increasing renewable energy.

Both countries have a lot of work ahead to get to these targets.

The administration says this will be achievable under existing law. It assumes the Environmental Protection Agency’s regulations to slash carbon pollution from power plants 30 percent by 2030 are in full swing. But there is also intense Republican opposition to the EPA’s plans, and to Obama’s. The new Congress is led by climate change deniers, who will obstruct the president’s plans. The next Senate Majority Leader, Mitch McConnell, has suggested he will use must-pass appropriations bills as leverage to force Obama into delaying or weakening his own climate regulations.