Even without the Clean Power Plan in place, coal's once-tight grip on U.S. power generation is expected to slip further and then remain roughly steady at best, as natural gas and renewables gain ground. Without the rule, those sources will help displace about 42 gigawatts of coal-generated power through 2026, according to Eurasia Group analysis of U.S. Energy Information Administration data.
If the rule is implemented, the nation will steadily reduce its reliance on coal-fired power generation through 2050, eventually mothballing about 100 gigawatts of capacity by that year, according to Eurasia Group.
Pruitt also told CNBC on Tuesday that reducing regulations that push utilities toward natural gas and renewable sources of energy will increase demand for coal at U.S. power plants. "There's hope and optimism now for the first time in many years. I think that's going to impact the demand," he said.
But that is not the view of Thomas Fanning, CEO of Southern Company, one of the nation's largest utilities. Fanning backs Pruitt on regulations, but he told CNBC's "Squawk Box" there isn't much Trump can do to juice demand for coal at home.
Any increases in U.S. coal supplies are likely to be sent overseas, said Fanning, who noted on Tuesday that foreign energy plants "don't have the natural gas that we do."
Even then, the International Energy Agency sees only limited prospects for American coal overseas — again, because of market factors. It forecasts that a three-year decline in U.S. coal exports will continue as demand in China declines, shipments out of Mozambique crowd out American coal in Brazil and Europe, and Colombia wields a price advantage over U.S. coal in the shrinking European market.
If Trump's policies cannot substantially increase demand for U.S. coal, the president will likely fail to deliver on a core campaign promise: to put miners back to work. The president has not put forward a backup plan for the industry, which has hemorrhaged workers as many companies have gone into bankruptcy.
And even if the United States does produce more coal, it still leaves many miners out of work. The Energy Information Administration forecasts a near-term bump in coal production will benefit the most productive mining areas — the places where it takes fewer workers to produce more coal. None of those places is in the Appalachian region, where Trump has focused his most visible political efforts.
That is not the picture Trump is painting. Just before signing his executive order on Tuesday, he turned to a miner and said, "Basically you know what this says? You know what this says, right? You're going back to work."
Rep. John Yarmuth, D-Ky., told CNBC Trump's promise of a coal revival is "one of the most cruel deceptions that are being played in the political realm these days."
"Even if it does increase demand in coal, in places like eastern Kentucky, Appalachia, those jobs won't come back because that coal's too expensive to mine. It's just not competitive anymore with natural gas," he said.