Clinton, Trump clash in first debate: CNN's Reality Check Team vets the claims.

(CNN)Hillary Clinton and Donald Trump clashed Monday in their first head-to-head debate of the general election season, with Trump in particular straying from the truth, CNN's Reality Check Team found.

The team of reporters, researchers and editors across CNN listened throughout the debate and selected key statements from both candidates, rating them true; mostly true; true, but misleading; false; or it's complicated.

By Laura Koran, CNN; Clinton claimed Trump "thinks that climate change is a hoax perpetrated by the Chinese," a charge Trump immediately denied. Who's telling the truth?

On November 6, 2012, Trump tweeted, "The concept of global warming was created by and for the Chinese in order to make U.S. manufacturing non-competitive."

Over a year later, Trump tweeted in response to weather reports, "Snowing in Texas and Louisiana, record setting freezing temperatures throughout the country and beyond. Global warming is an expensive hoax!"

And Trump's doubts have continued into the campaign season.

Last September, when he was seeking the Republican nomination, Trump told CNN that while he supports clean air and water, "I am not a believer in climate change."

Trump went on to refute the connection between climate change and a rise in extreme weather phenomenon.

"Weather changes," Trump said. "And you have storms, and you have rain, and you have beautiful days, but I do not believe that we should imperil the companies within our country. And by the way, China is doing nothing."

In March, Trump took a more nuanced approach, telling a Washington Post editorial board that he doesn't believe climate change is the result of man-made causes.

"I think there's a change in weather," he said. "I am not a great believer in man-made climate change. I'm not a great believer."

And while Trump has repeated the hoax line on multiple occasions, he's walked back the assertion that it was created by the Chinese, saying he meant that as a joke ... sort of.

"I often joke that this is done for the benefit of China," Trump said on Fox News' "Fox & Friends." "Obviously, I joke, but this is done for the benefit of China, because China does not do anything to help climate change."

While Trump doubts the validity of climate change, his company has prepared for it. According to a Politico report, Trump International Golf Links applied for a permit to build a sea wall at his golf course in Ireland to protect it from "global warming and its effects."

Our verdict: True. While Trump has wavered on the cause of climate change, he has repeatedly denied its existence and called it a hoax.