For years, those who fought action on climate change shared the same talking point: Why should the U.S. reduce its emissions when China is burning coal and growing its economy?

My, how the tables have turned.

Now China is moving forward on climate action with steps including having built two wind turbines every hour last year. And it's worried the U.S. is about to take a giant step backward.

This concern prompted China's top climate negotiator, Xie Zhenhua, on Tuesday to offer a rare rebuke of an American presidential candidate.

In this case, Xie directed his criticism at Republican nominee Donald Trump for promising to pull the U.S. out of the Paris Climate Agreement.

According to Reuters, Xie warned that leaving the agreement or failing to live up to its commitments would be a mistake for a potential Trump administration.

"If they resist this trend," Xie said of a Trump White House. "I don't think they'll win the support of their people, and their country's economic and social progress will also be affected.

"I believe a wise political leader should take policy stances that conform with global trends," Xie said during a press conference.

Image: Evan Vucci/AP

Trump has called global warming a "hoax," and in one infamous tweet in 2012 accused China of concocting the issue "in order to make U.S. manufacturing non-competitive."

The Paris Agreement, which will be enforced starting Friday, commits the entire global community to taking action to reduce emissions of global warming pollutants and adapt to climate change impacts.

It sets a goal of limiting global warming to under 2 degrees Celsius, or 3.6 degrees Fahrenheit, above preindustrial levels by 2100.

However, countries have not yet proposed actions that are sufficiently ambitious to actually meet that goal; emissions are set to soar well above the threshold needed to meet it. The next round of U.N. climate talks begins in Marrakesh on Nov. 7.