President Trump fulfilled one of his big campaign promises on Tuesday: He signed an executive order that directed the Environmental Protection Agency to roll back the Obama administration’s Clean Power Plan.
That plan was intended to cut harmful carbon emissions by replacing coal-fired power plants with renewable energy sources. Trump wants to repeal it as a step towards boosting the struggling coal industry.
But in Florida and across the country, it's doubtful the rollback will have much impact -- positive or negative, says University of Miami economist David Kelly.
"What's been going on is a switch to more natural gas and away from coal," Kelly said. "What this means, probably, is slowing the rate of decline in coal use."
Coal use is declining because competing sources of energy are rising. In particular, the price of natural gas has decreased in recent years thanks to hydraulic fracturing, or fracking, which uses high-pressure streams of water and chemicals to extract natural gas from deep underground. Kelly said that as the supply of natural gas has increased its price has decreased and the demand for coal has fallen. Energy companies have converted coal-fired power plants so they'll burn natural gas instead.
Sixty percent of Florida's energy comes from natural gas, Kelly said.
"It's only going to continue that we move more in the direction of natural gas and away from coal."
President Obama put the Clean Power Plan into effect with an executive order in 2015. It required states to cut their carbon emissions by 2030. But the plan wasn't fully implemented: States including Florida sued and the plan was tied up in court.
Kelly said following Trump's executive order for the rollback that the lawsuit probably will be dropped. But he said the rollback will likely face court challenges of its own from states that support the power plan. And, the rollback requires review by the Environmental Protection Agency. So it could take years to go into effect -- maybe so long that a new president comes into office and changes course completely.
Kelly said the lack of consistency poses an economic challenges to the energy companies.
"Fights in the courts and executive orders really create a lot of uncertainty," Kelly said. "It's not good for planning what type of power plant you're going to build, which is, like, a 20-year investment."
Natural gas releases significantly less carbon than coal, but also contains another harmful greenhouse gas -- methane.