A top Chinese climate scientist said it would be "foolhardy" of U.S. President Donald Trump to withdraw from the global climate-change agreement known as the Paris accords.

A global-warming skeptic, Mr. Trump has vowed to cancel the accord, which the Obama administration helped broker, in his first 100 days as president.

In an interview, Ding Zhongli, vice president of Chinese Academy of Sciences, a government think tank, took a jab at Mr. Trump’s stance and his elevation to office. "I think he is cute, saying whatever comes to his mind. I think the U.S. is a cute country too, because a person like him became the president," said Prof. Ding.

Mr. Ding, who said the science is clear on climate change and that it’s urgent that everyone makes sacrifices to fight it, was referring to Mr. Trump’s labeling of climate change as a Chinese invention. The president said in a 2012 tweet that the Chinese created “the concept of global warming.”

He also said the Paris agreement, reached in late 2015, was based around each country’s own proposal and didn’t ask too much of the U.S. As part of the accord, the Obama administration committed to cutting U.S. greenhouse-gas emissions between 26% and 28% by 2025 based on 2005 levels.

Unlike the U.S. where a new president can overturn the former’s administrative rules if they are not written into law, China’s government’s policies are more consistent due to one-party rule, Mr. Ding said.

The 60-year-old geologist recently landed in the spotlight after a video clip of comments he made in 2010—a few months after the Copenhagen climate conference ended in a deadlock—began circulating online. The academic, who studies ancient climate, was one of the most outspoken advocates for giving developing countries, including China, higher emission allocations.

Chai Jing, then a reporter with China Central Television, questioned the professor’s suggestion that the fairest way would be to use a per capita measure to set countries’ allowed emissions, asking whether China shouldn’t join the global effort and cut emissions as much as possible.

“Then I want to ask: Are Chinese humans? That’s a fundamental question,” Prof. Ding said in the video clip circulating widely on China’s social media over the past few weeks, when the majority of the nation was blanketed in thick smog. His argument: that a per capita count of emissions would be more equitable and treat all people the same.

The clip ignited a debate on China’s social media about the balance between further economic advancement and cleaner air. Support for the professor’s remarks flooded China’s social media, with some calling him the "backbone" of the country. Others, however, thought the comments sought to defend pollution.

Asked about the online comments, Prof. Ding said he was just calling for fair emission rights for China. He said many read too much into it.

When he was young, he said, there was no smog but he didn’t have enough to eat and decent clothes to wear. One cannot both enjoy the benefits of industrialization and completely avoid the damages of it, he said.

When setting targets for future carbon emissions, global leaders should consider historical emissions, per capita emissions as well as consumption, Prof. Ding said in the interview.

"Steel made in China is sold to the U.S. The emission is done in China but the consumption happens in the U.S. It’s unfair to attribute that emission to China," he said.

The scientist said he believes in the science of climate change but takes issue with the argument by some scientists that an increase of two degrees Celsius in global temperatures over preindustrial levels will have catastrophic consequences.

Unlike in the U.S., climate-change skeptics in China are an extremely rare breed—something that Mr. Ding posited was the result of better science education.

“Chinese people may learn physics better than Americans. Ordinary people with some education have a basic knowledge of physics," he said, adding that he has some doubts about Mr. Trump’s grasp of the subject.

In a speech last week at Davos, Chinese President Xi Jinping urged other nations to stick to the Paris agreement, calling it a "responsibility we must assume for future generations."

Chinese citizens, however, show a comparatively low level of concern about global warming, with around one-third calling it a "major threat" to their nation, according to the Pew Research Center. By contrast, that figure is 53% in the U.S.

The White House didn’t respond to emailed requests for comment.

—Liyan Qi and Te-Ping Chen