Where Republican Presidential Candidates Stand on Climate Change

As wildfires in Canada have sent masses of smoke over the United States this week, engulfing much of the Northeast in a yellow haze of hazardous air pollution, scientists are clear that we are seeing the effects of climate change. But the Republicans campaigning for the presidency have largely downplayed the issue and rejected policies that would slow rising temperatures.

On Wednesday, even as the country experienced one of its worst days on record for air quality, with New York City especially hard-hit, former Vice President Mike Pence said in a town-hall event on CNN that “radical environmentalists” were exaggerating the threat of climate change.

His response reflected what has become a pattern among Republican officials. Many of the candidates acknowledge that climate change is real, in contrast to party members’ years of outright denial. But they have not acknowledged how serious it is, and have almost universally rejected the scientific consensus that the United States, like all countries, must transition rapidly to renewable energy in order to limit the most catastrophic impacts.

Here is a look at where some of the major Republican candidates stand.

Donald J. Trump

As president, Donald J. Trump rolled back more than 100 environmental regulations, mostly aimed at reducing planet-warming emissions and protecting clean air and water; appointed cabinet members who were openly dismissive of the threat of climate change, including Scott Pruitt as head of the Environmental Protection Agency; and withdrew the United States from the Paris Agreement, under which almost every country had committed to try to limit warming to 2 degrees Celsius above preindustrial levels.

President Biden rejoined the Paris Agreement and undid many of Mr. Trump’s policies, but the damage may not be fully reversible. A report last year from researchers at Yale and Columbia found that the United States’ environmental performance had plummeted in relation to other countries as a result of the Trump administration’s actions.

Mr. Trump has given no indication that his approach would be different in a second term. He has repeatedly minimized the severity of climate change, including claiming falsely that sea levels are projected to rise only ⅛ of an inch over 200 to 300 years. But according to the National Oceanic and Atmospheric Administration, sea levels are rising by that amount every year.

Ron DeSantis

Gov. Ron DeSantis leads a state, Florida, that is on the front lines of climate change: It has been hit hard by hurricanes, which are becoming more frequent and more severe as the Atlantic Ocean gets warmer.

But Mr. DeSantis has dismissed concern about climate change as a pretext for “left-wing stuff” and said on Fox News last month, “I’ve always rejected the politicization of the weather.”

He has, however, taken significant steps to fortify the state against stronger storms and rising waters. Among other things, he appointed the state’s first “chief resilience officer” and backed the Resilient Florida Program, which has sent hundreds of millions of dollars to vulnerable communities to fund projects like building sea walls and improving drainage systems.

Scientists support these sorts of adaptation efforts, because the climate has already changed enough that even aggressive emission reductions will not avert all the effects. But they are also clear that such measures are not enough on their own.

Nikki Haley

Nikki Haley, a former governor of South Carolina, has acknowledged that climate change is real and caused by humans, but she has generally rejected governmental efforts to reduce emissions. Her advocacy group Stand for America said that “liberal ideas would cost trillions and destroy our economy.”

As ambassador to the United Nations during the Trump administration, Ms. Haley was closely involved in withdrawing the United States from the Paris Agreement. At the time, she said, “Just because we pulled out of the Paris accord doesn’t mean we don’t believe in climate protection.” Over the next three years, the Trump administration systematically reversed climate protections.

But Ms. Haley has supported greater use of carbon capture technology to remove carbon from the air. She and some other Republicans — including another presidential candidate, Gov. Doug Burgum of North Dakota — have presented this as a way to limit climate change while continuing to use fossil fuels. Many experts agree that carbon capture could be a powerful tool, but it is unlikely to be sufficient on its own, in part because of its high cost.

Mike Pence

Mr. Pence has acknowledged that climate change is real. He said during the 2016 campaign, “There’s no question that the activities that take place in this country and in countries around the world have some impact on the environment and some impact on climate.”

But that assertion falls short of the scientific consensus that human activity is the primary driver of climate change. He has also downplayed the severity, like in his comments this week that “radical environmentalists” were exaggerating climate change’s effects. And as vice president, Mr. Pence had a hand in Mr. Trump’s defiantly anti-climate agenda, including defending the decision to withdraw from the Paris accord by saying Mr. Trump had stood up for “America first.”

Mr. Pence’s political organization, Advancing American Freedom, has denounced “the left’s climate radicalism” and called for a rejection of “climate mandates.” It has also called for expediting oil and gas leases and taking other steps to “unleash the full potential” of fossil fuel production in the United States.

Tim Scott

Senator Tim Scott of South Carolina has also acknowledged that climate change is occurring, once telling The Post and Courier, his home-state newspaper: “There is no doubt that man is having an impact on our environment. There is no doubt about that. I am not living under a rock.”

At the same time, he has opposed most policies that would curb carbon dioxide emissions. During the Obama administration, Mr. Scott challenged a regulation that would have required utilities to move away from coal and adopt wind, solar and other renewable power. During the Trump administration, he argued for dumping the Paris Agreement. And last year, he voted against President Biden’s expansive climate and health legislation that will invest about $370 billion in spending and tax credits over 10 years into clean energy technologies.