In 2015, the Obama administration’s Environmental Protection Agency finalized plans for a program to reduce carbon dioxide emissions—which contribute to climate change and endanger public health—from power plants. But on Tuesday, the Trump administration revealed a new version that’s significantly more coal-friendly.

The proposed Affordable Clean Energy rule, or ACE, would “respect the rule of law,” bring down electricity costs, and give state regulators and the energy sector “regulatory certainty,” said acting Environmental Protection Agency Administrator Andrew Wheeler in a press conference Tuesday.

It’s questionable, however, how affordable or clean a plan that props up the declining coal industry can be.

Coal, the hardened remains of ancient plant matter, is composed primarily of carbon, hydrogen and some oxygen, sulfur, and nitrogen. When burned, the bonds holding these atoms together break to release energy and rearrange to form mainly carbon dioxide and water, but also oxides of sulfur and nitrogen and toxic combustion byproducts including mercury and trace heavy metals.

The Clean Power Plan, finalized in 2015, would have set the nation’s first carbon dioxide emissions standards for power plants—if it hadn’t been stayed by the Supreme Court in 2016. Under the program, states were required to reduce carbon emissions through a combination of tools, including setting cleaner emissions rates for power plants and operating dirtier power plants less frequently in favor of units that used lower-emitting natural gas or zero-emitting renewable sources. Altogether, the plan would have reduced carbon emissions from the U.S. power sector by 32 percent from 2005 levels by 2030—about 870 million tons, or the equivalent of taking 166 million passenger cars off the road in a single year.

Such a reduction was projected to create $20 billion in climate benefits and $14 billion to $34 billion in health benefits by preventing 3,600 premature deaths, 1,700 heart attacks, 90,000 asthma attacks, and 300,000 missed work and school days each year, according to the EPA.

In contrast, Trump’s EPA estimates its plan would reduce emissions of carbon dioxide equivalent to taking five million cars off the road by 2030—about 3 percent of the reductions projected under the Obama administration’s Clean Power Plan. It would make U.S. electricity prices cheaper by half a percent at most compared to the Clean Power Plan, but increase coal production for energy by up to 6 percent.

The rule appears “to direct states, if they wish, to work to make coal plants more efficient,” says Janet McCabe, former acting head of the EPA’s air office under Obama. McCabe worked on the Clean Power Plan. “Efficiency improvements at a coal plant are not even near as clean as moving to wind, solar, or even natural gas.”

And more efficient power plants can still emit more pollution overall if they run for longer periods. Meanwhile, states would have the discretion to decide how best to apply efficiency standards to their power plants. The proposal would also revise a separate Clean Air Act requirement called New Source Review meant to modernize air pollution controls whenever facilities expand or make upgrades that increase their overall emissions.

“You only need relief from New Source Review in cases when you increase pollution,” McCabe says.

The proposal affects about 300 facilities, including about 40 coal-fired power plants for which the Sierra Club estimates have planned retirement deadlines.

These retirements reflect an ongoing, market-driven move by the power sector away from coal. Since 2015, natural gas has become the most-used fuel for electricity production, according to the U.S. Energy Information Administration. Coal-fired generators, on the other hand, made up more than half of the electric capacity retired in 2017. No new coal-fired generators were added to the fleet last year for the first time in at least a decade.

Especially in the era of climate-change induced hurricanes and wildfires, encouraging coal production when its demand is on the decline flies in the face of common sense, says Jane Williams, executive director of environmental advocacy group, California Communities Against Toxics. “It’s like wanting to put lead back into the ammunition.”