For years, the Obama administration prodded, cajoled and beseeched China to make commitments to limit the use of fossil fuels to try to slow the global effects of climate change.

President Obama and other American officials saw the pledges from both Beijing and Washington as crucial: China is the largest emitter of greenhouse gases, followed by the United States.

In the coming years, the opposite dynamic is poised to play out. President Trump’s signing of an executive order on Tuesday aimed at undoing many of the Obama administration’s climate change policies flips the roles of the two powers.

Now, it is far likelier that the world will see China pushing the United States to meet its commitments and try to live up to the letter and spirit of the 2015 Paris Agreement, even if Mr. Trump has signaled he has no intention of doing so.