Mr. Pence, the president’s influential No. 2, has appeared to question climate science, although his aim was less to question the existence of climate change as to stand up for the coal-fired power plants that provide his home state, Indiana, with most of its electricity.

What he has said:

“It’s just a few years ago, we were talking about global warming, which is — we haven’t seen a lot of warming lately. I remember back in the ’70s when we were talking about the coming ice age. And, look, you know, we have — we’ve had a tough winter. And in the Midwest, we’re — we’re made of hardy stock. We’ve seen these kind of winters before. And we’ll shoulder through them. We’ll leave the scientific debates for the future.” MSNBC interview, 2014.

In an interview with CNN in September, Mr. Pence, like his boss, modulated that view.

“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 Donald Trump and I say let’s follow the science, but for heaven’s sakes let’s not go rushing into the kind of restrictions on our economy that are putting Americans out of work and, frankly, are driving jobs out of this country.”

Stephen K. Bannon

Mr. Trump’s influential senior strategist is the former chief executive at Breitbart News, which regularly publishes articles with headlines like “Global Temperatures Plunge. Icy Silence From Climate Alarmists” and “Climate Change: The Greatest-Ever Conspiracy Against the Taxpayer.” Mr. Bannon is said to be pushing Mr. Trump to withdraw the United States from the 2015 Paris agreement, which committed nearly every country to take action on carbon dioxide pollution.

What he has said:

The national debt is “not a manufactured crisis like global warming or the health care crisis. This is a — this is an existential crisis.” Fox News, 2010.

Scott Pruitt