Donald Trump on Thursday pledged to cancel the Paris climate agreement and aggressively pursue U.S. fossil fuel development, during a speech at a petroleum conference in North Dakota.
He attacked Democratic frontrunner Hillary Clinton's positions on energy policy, drawing sharp contrasts between the two on an issue that could be a factor in the general election.
Trump delivered his remarks in a state where oil and gas production have rocketed up 10-fold over the last decade, helping make the United States the world's leading fossil fuel producer.
According to Trump, the transformation happened "in spite of massive new bureaucratic and political barriers." He said President Barack Obama has "made life much more difficult for North Dakota, as costly regulation makes it harder and harder to turn a profit." And under Clinton, he said, "things will get much worse."
In his first 100 days in office, Trump said, he would roll back regulations on drilling, "cancel the Paris climate agreement and stop all payments to U.N. global warming programs."
An illustration picture taken on Dec. 10, 2015 in Paris shows a draft for the outcome of the COP21 United Nations conference on climate change next to a picture of the Eiffel Tower. Trump has promised to withdraw from the agreement.
Environmentalists condemned the speech. "He basically said whatever the oil and gas industry folks wanted to hear," while disregarding the impact on air, water and climate, said League of Conservation Voters spokesman Seth Stein.
Trump "didn't seem to have any grasp of what is actually in the Paris agreement," said Oren Cass, a senior fellow at the Manhattan Institute and adviser to 2012 Republican presidential candidate Mitt Romney. He supports Trump's focus on domestic energy and reducing regulations, but said Trump shows a worrying failure to grasp "the facts and the way these things actually work."
Trump's remarks came on the day he tallied enough delegates to be the GOP presidential nominee. And by focusing on energy policy, Trump emphasized a subject that has not drawn much attention in primary contests but could be important in the general election.
"If you think about a Trump vs. Clinton, or certainly a Trump vs. [Democratic contender Bernie] Sanders race, this is going to be a very prominent area of disagreement, both in the policy specifics and the broader world view and approach to governing," he said. "It's a very sensible element in a pivot to the general election."
Clinton called the U.N. climate agreement negotiated in Paris last December a "historic step forward" and "a testament to America's ability to lead the world." She has advocated a transition away from fossil fuels toward cleaner energy sources in order to fight climate change.
In contrast to Trump, who has described climate change as a "hoax," Clinton has said it is "clearly man-made and man-aggravated."
Recent polls show U.S. voters are coming around to Clinton's point of view.
"There are majorities that agree that this is something that's happening and this is an issue that they want action on," said Stein.
A recent Gallup poll found 64 percent of Americans are worried about climate change, and a record 65 percent say humans are responsible.
FILE - Democratic presidential candidate Hillary Clinton, center, arrives to speak at a get out the vote event at Transylvania University in Lexington, Ky., Monday, May 16, 2016.
Conservative Republicans are the least likely to believe climate change is happening, according to a Yale University-George Mason University poll. But even this group is having a change of heart. Believers remain a minority at 47 percent. But that's up 19 percentage points in the last two years.
And while climate change is not a top issue on voters' minds, the survey found that opposing climate action did not win votes. Forty-five percent of respondents said they would be less likely to vote for a candidate who strongly opposed measures to reduce global warming. Only 11 percent said said they would be more likely.
Voters also are turning against one of the techniques that has made the United States the world's top energy producer: hydraulic fracturing, or fracking. Gallup found just over half of respondents opposed the practice, up from 40 percent last year.
Environmentalists criticize fracking for causing water pollution, methane leakage and earthquakes.
But experts credit the natural gas boom with helping cut U.S. greenhouse gas emissions. Natural gas is cleaner than coal. Now it's cheaper as well.
When it comes to fracking, Clinton faces criticism from both sides. As secretary of state, she backed natural gas development as a "bridge fuel" between coal and renewable energy. But she has backed away from supporting it in the United States, under fire from Bernie Sanders, who opposes the practice.
"The fracking issue is going to be a very interesting one in the general election because Clinton has been pushed pretty far to the left on it by Sanders," Cass said. "She tried to leave herself a lot of wiggle room... But I think the contrasts are going to at least feel very clear."