Nearly a year before his surprise victory in the U.S. presidential election, Donald Trump mocked climate change concerns and prescribed a fix for a cold front that had descended on New York City and the Northeast. “We could use a big fat dose of global warming!” he wrote on Twitter at the time.

Now, 13 months later, Trump is set to inhabit an office that could have significant influence on U.S. efforts to combat man-made climate change. The president-elect, who has called global warming a “hoax,” has promised to dismantle the Environmental Protection Agency and has railed hard against environmental regulations to reduce greenhouse gas emissions.

When it comes to some of Obama's most recognizable environmental regulations, Trump may encounter a mix of possible challenges if he tries to dismantle them. For automobile energy efficiency standards finalized in 2012, untangling those regulations from the federal government would likely  be a drawn out process, for instance. On the other hand, it's hard to predict what exactly Trump may encounter when it comes to other regulations, such as Obama's Clean Power Plan that would cut greenhouse gas emissions from power plants but is currently held from being finalized by the courts. 

At the same time, Trump may face difficulties to deliver on his campaign promise to bring coal power back to the United States. As coal plants have grown old and many have retired recently, natural gas has become increasingly affordable compared to coal. Natural gas overtook coal in 2016 to make up the largest share of U.S. electricity production, according to the U.S. Energy Information Administration, and average costs for natural gas have dropped to within a dollar of coal production costs. Meanwhile, clean water has proven to be important for Americans, with more than 60 percent indicating in a recent Gallup poll that clean drinking water was a major concern for them.

One of the sure things Trump will have control over as president is the Environmental Protection Agency's budget. If he chooses to leave funding for the EPA off the annual budget, the  EPA would effectively be stopped from enforcing any rules.

International Business Times caught up recently with Christine Todd Whitman, the former governor of New Jersey,  former EPA administrator for President George W. Bush and an advocate for nuclear power, to learn more about what Trump will encounter when he tries to shape the agency she used to run. Here's what she said:

Trump Wants To Cut Back On Regulations And Has Threatened to Gut The EPA. How Much Power Does He Have To Do So As President? There are things he can certainly do. He can take us out of the Paris Climate Accord. He can do things like that. But as far as the regulations go, if they’ve gone final, you can’t just do away with them. You have to go through a process in order to do that. If there are regulations that have been litigated and held up in the courts, that will make it more difficult to repeal them. 

Their first order of business will be that they’ll have to go through what’s final and what may not be final. The other thing he can do is slow down appointments there and put somebody in charge that doesn’t believe in climate change.

These are the first things that he can do: revisit the budget and cut back dramatically on what the agency is used for. Cut back on enforcement and put a lid on any further regulations while you decide what you want to do.

Trump Has Promised To Bring Back “Clean Coal.” Is that Realistic? Donald Trump’s going to find that a lot of coal is not going to come back. It can’t come back. The utilities have cut down on coal not because of regulations but because of the low cost of natural gas.

Some of them have started dismantling their coal plants. It’s not going to come back.

There’s low sulfur coal but there’s no such thing as clean coal.

Are There Political Concerns For Trump In Going After The EPA And Environmental Regulations? You know that’s fine to go after regulations and find some that overstep because there are some. But when you get into it as a wholesale regulation… I understand the goal but you don’t want to do this kind of thing blindly because people do care about the quality of their environment.

Future generations are going to pay a huge price if we ignore climate change.

I think that what so many people forget is that the EPA was established because the public wanted it. Every time you do a poll you have 81 percent or better of people who say they care about clean air, they care about clean water. We want to see these things protected.

It’s something that if you walk away too far, too fast. than you’re going to incur the wrath of the public.

The EPA Is Made Up Mostly Of Life-long Employees. Does That Mean Anything For Trump’s Policies There? It does and it’s amazing how the career people can slow things down. They can slow things down within the agency and be a little recalcitrant. The fear I have is that in fact we’re going to lose a lot of the career staff because they’re eligible for retirement and if they think the agency is going to be sidelined and not committed to protecting human health and the environment they’re going to leave.

You don’t want to lose all that institutional knowledge and I’m afraid that’s where we’re going to see the biggest problem and how that might play out.

This interview has been edited for clarity and length.