How will the Trump White House treat climate change? Why it's so hard to know.

Donald Trump’s three latest cabinet nominees are part of the president-elect’s campaign promise to “drain the swamp in Washington.”

Scott Pruitt has been tapped to lead the Environmental Protection Agency – the same agency he repeatedly sued as Oklahoma attorney general. Former Texas Gov. Rick Perry was named secretary of the energy department – which he advocated to eliminate in his 2012 presidential bid. Rex Tillerson, named to the nation’s top diplomatic post, fostered his international relationships as chief executive of ExxonMobil, not as a politician.

On the face of it, this looks like a team ready to radically alter US climate change policy. But it's not that simple.

Most environmentalists and climate scientists don’t expect Trump to continue President Obama’s efforts to curb greenhouse-gas emissions and promote renewable energies. Beyond that, however, they’re not sure what he will do. Besides Mr. Pruitt, there are nuanced caveats to the climate change policy forecasting around Trump’s newest cabinet picks, as well as his daughter and close adviser, Ivanka.  

Part of the uncertainty, say experts on climate change and politics, lies with Trump’s appointment of nominees with key philosophical differences with the missions of the agencies they have been asked to run, or as Michael Svoboda, the director of George Washington University’s sustainability minor, calls it, “political nullification.”

“In several instances, we’re rejecting some of the premises of the agencies these people are being asked to run,” Dr. Svoboda tells The Christian Science Monitor in a phone interview. “There is a larger argument here about the role of government that is not quite encompassed by left versus right and policy disputes ... Depending on how these people exercise their authority, one could read underneath this as an effort to nullify climate science.”

The ambiguity about the Trump administration’s climate policies starts with the president-elect himself. As a real-estate mogul,  Trump sought to build a sea wall around his seaside golf resort in County Clare, Ireland. As The Christian Science Monitor reported in May:

In its permit application to do this, the Trump subsidiary running the place explicitly cites climate change as a major reason it needs a sea wall. It cites predictions of a rise in sea level as a result of global warming. If those are correct, much of the Irish coast will experience more erosion.

As a presidential candidate, Trump repeatedly said climate change was a “hoax” invented by the Chinese to undercut US manufacturing, though he also said during the campaign that the remark was a joke. Shortly after he was elected, Trump told The New York Times that there is "some connectivity" between climate change and human activity. But in an interview that aired this past Sunday, Trump told Fox News that “nobody really knows” if climate change is real.

This ambiguity before Jan. 20, 2017, Inauguration Day, contrasts with the previous two administrations. Before Mr. Obama and President George W. Bush assumed office, it was clearer where they stood on climate change and which of their advisers had their ear. Shortly after he took over the White House, Obama named John Holdren to be his science adviser, a carry-over from President Clinton.

Before Mr. Bush assumed office, critics expected him to put climate policy on the back burner, after calling it “junk science” during the campaign, according to The Independent. He did just that for most of his eight years in his office, but is credited with the passage in 2007 of the Bali Action Plan, the first time ever fast-growing developing countries , including China, Brazil, India and South Africa, were agreed they would submit cleanup plans, according to Politico.

“When you have a more seasoned politician coming in, you have a better idea of who his close advisers are,” Henrik Selin, a professor at Boston University’s Frederick S. Pardee School of Global Studies, says, comparing Obama and Bush to Trump. “Who his key advisers will be on climate change and what they will tell the president and what the president will act on are all unknowns.”  

Among Trump’s top officials, Pruitt, his pick to lead the EPA, perhaps offers the clearest record of how his climate change views will translate to action. Pruitt has denied the veracity of climate change, co-authoring an article for the National Review that stated “the debate is far from settled. Scientists continue to disagree about the degree and extent of global warming and its connection to the actions of mankind.”  Actually, 97 percent of climate scientists agree global warming is occurring thanks to human activity, according to NASA.

“Pruitt, is known as an Oklahoma fossil-fuel advocate and an attorney general who has fought environmental regulations. By all signs, agency budget cuts and a regulatory rollback are coming,” writes The Christian Science Monitor’s Zack Colman, about how Pruitt might try to reshape the EPA.

But there are possible crosscurrents within the emerging Trump administration. Ivanka Trump, the president elect’s daughter and one of his closest advisers, has said she wants climate change to be one of her signature issues. But she hasn’t said how. She did recently coordinate meetings between the president-elect and Al Gore and Leonardo DiCaprio. She also will reportedly assume some of the roles of first lady.  

Mr. Tillerson’s public skepticism about climate change is a lot more nuanced. The chief executive of ExxonMobil, the world’s largest oil company, Trump’s pick for secretary of State has acknowledged humans have likely contributed to rising temperatures. He and his company have also voiced support for the Paris climate change agreement. But his solution to the problem has been engineering and risk management, not emissions cuts, according to The Washington Post. He will be at the helm of US effort to implement – or scuttle – the Paris deal. But that, too, could depend on how much influence he actually has over foreign policy decisions, says Dr. Selin at Boston University.

“Will be president Trump actually listen to him or not?” Selin asks rhetorically.

Governor Perry has also questioned climate science while he promoted coal-fired power. But in the 12 years he was governor of Texas, he developed “one of the most aggressive renewable electricity mandates in the country; becoming the nation’s top wind power state; investing in the electric grid in an unprecedented way; and applying for Energy Department grants to support projects within the state,” writes the Monitor’s Mr. Colman. 

This report contains material from the Associated Press.