Trump claimed that the United States had the largest carbon emissions reduction, highlighted China's role in emitting carbon, and claimed none of America is exposed to air pollution levels above those suggested by the World Health Organization.
The town hall event is slated to last for seven hours, although that wasn't enough for CNN's chief climate correspondent.
"There was so much cry out from those voters who will caucus for Democrats or independents who put this topic at the very top of their concern list," CNN's Bill Weir said. "And many were calling for a dedicated climate debate with all 10 on stage. The DNC didn’t go for that for whatever reason. And so we thought: 'Why don't make it happen?'"
He continued: "Look, I’m biased. I think we could do a town hall a day on this and it wouldn’t be enough to cover it because it’s everything. It’s everything in our lives, from energy to politics to geopolitics to psychology to history."
Climate change has become a key issue in the 2020 presidential cycle as Democratic candidates have issued dire warnings about its impact and pushed massive policy proposals for dealing with the issue.
"The Democrats’ destructive 'environmental' proposals will raise your energy bill and prices at the pump," Trump tweeted on Wednesday. "Don't the Democrats care about fighting American poverty?"
He went on to blast the Paris Climate Agreement, from which the president withdrew the U.S. in 2017. "The badly flawed Paris Climate Agreement protects the polluters, hurts Americans, and cost a fortune. NOT ON MY WATCH!" Trump tweeted.
Leading Democratic candidates have vowed to rejoin the agreement as part of proposals that they say will prevent large-scale damage from climate change.
"The cost of inaction is unacceptable," the campaign for Sen. Bernie Sanders, I-Vt., claimed. "Economists estimate that if we do not take action, we will lose $34.5 trillion in economic activity by the end of the century. And the benefits are enormous: by taking bold and decisive action, we will save $2.9 trillion over 10 years, $21 trillion over 30 years, and $70.4 trillion over 80 years."
But the field's plans, many of which endorse the "Green New Deal" (GND), could inflict a heavy financial toll if conservative groups' estimates prove true.
The right-leaning Competitive Enterprise Institute concluded that the GND would cost the average household at least $70,000 in the first year of its rollout, and a cool $250,000 dollars after five years. The Heritage Foundation predicted that reaching just a portion of the GND's emissions reductions goal would cost $15 trillion in gross domestic product.
Fox News' Joseph A. Wulfsohn contributed to this report.