Although the Republican presidential nominee claimed that he never called global warming a "hoax," Donald Trump's climate change statement at the first debate contradicts what he's said in the past. In 2012, Trump tweeted that he believed that the "concept" of global warming was created "by and for the Chinese" in order to, somehow, hurt U.S. manufacturing. But at the first presidential debate, Trump denied he ever said that when opponent Hillary Clinton brought up Trump's former comments. "I did not — I do not say that," he said.
2012 wasn't the last time he expressed disbelief in the "concept" — he called global warming a hoax on Jan. 24, 2014 (this time in capital letters), an "expensive hoax" on Jan. 28, 2014, and on that same day, called it "bullshit". On Sept. 24, 2015, almost exactly a year ago, Trump once again said he doesn't "believe in climate change", and in January of this year, reiterated that he thinks climate change "is done for the benefit of China." Apparently between then and now, Al Gore or someone else got a hold of him and really made him see the light about the polar ice caps melting.
Trump, who has made something of a habit of denying past statements even happened, told a bold-faced lie within the first 20 minutes of this debate by saying he "never said that." Maybe his definition of "said" doesn't include tweets, or maybe he's referencing the time he said his 2012 statement on China and climate change was a "joke". Either way, it doesn't look good for him, and makes it seem like the concept of fact-checking is completely foreign to the Trump campaign.
Climate change is far from the only issue Trump's changed his tune on. He has made a whopping 117 policy shifts on 20 issues since announcing his candidacy in June 2015. The only thing more absurd than his well-documented flip-flopping is that these massive shifts aren't a bigger part of rhetoric about the Republican nominee.