The Environmental Protection Agency on Wednesday killed President Obama’s signature climate change policy, the Clean Power Plan (CPP). It’s one of the few definitive wins in the Trump administration’s full-court press to undo and weaken environmental regulations.

Speaking before an audience that included coal miners wearing reflective shirts and hard hats, EPA Administrator Andrew Wheeler criticized the Obama policy, which required states to meet targets for cutting greenhouse gas emissions from power plants and aimed to reduce US power sector emissions 32 percent below 2005 levels by 2030.

“The CPP would have asked low- and middle-income Americans to bear the costs of the previous administration’s climate plan,” Wheeler said. “One analysis predicted double-digit electricity price increases in 40 states under the CPP.”

The EPA is still required to regulate greenhouse gases, but the CPP’s new replacement, the Affordable Clean Energy (ACE) rule, is drastically weaker. The ACE rule would lower power sector emissions by 11 million tons by 2030, or between 0.7 percent and 1.5 percent. The EPA noted that long-term industry trends are expected to still push emissions down 35 percent, but that’s largely independent of the ACE rule.

Speaking at the announcement, White House acting Chief of Staff Mick Mulvaney said Wednesday that US emissions are “flat or down.” That is wrong. In fact, US greenhouse gas emissions are on the rise after years of decline.

So the new ACE rule is likely to do little to slow the US power sector’s impact on the global climate. According to some researchers, the new policy itself could actually increase greenhouse gas emissions, even compared to business as usual. And according to the EPA’s own assessments last year, the proposal will lead to thousands more deaths from air pollution.

However, environmental groups are gearing up to file legal challenges to the ACE rule. And despite its intentions, the new regulation would do little to slow the decline of the US coal industry.

The EPA is required to regulate greenhouse gases, but the law doesn’t say it has to be enthusiastic about it

As much as the Trump administration doesn’t want to do it, the EPA must regulate greenhouse gases. In 2007, the Supreme Court ruled 5-4 in Massachusetts v. EPA that the agency has to limit greenhouse gases under the Clean Air Act if they’re a threat to public health. The EPA’s 2009 endangerment finding for carbon dioxide determined just that.

So the Trump administration couldn’t just repeal the CPP; it needed a plausible replacement to fight climate change. The ACE rule is an attempt at that.

“I believe this is the first rule in EPA’s history that acknowledges the existential threat of climate change but by the agency’s own admission does absolutely nothing to stop it,” said former Obama EPA Administrator Gina McCarthy in a statement.

The critical detail here is how the ACE rule intends to lower emissions compared to the CPP. The EPA is required to lay out a standard known as “best system of emission reduction.” Under the Obama administration, this included pricing carbon dioxide, switching to cleaner power generation fuels, or capturing carbon dioxide emissions.

The new ACE rule leans on one method: efficiency. The technical term is “heat rate improvement,” and it means is that fossil fuel-burning power plants would be pushed to draw more energy from the same amount of fuel. This would lower the carbon intensity of the energy generated.

However, generating more energy from the same amount of fuel makes the fuel more cost-effective. That in turn could lead to a rebound effect where utilities end up burning more fuels like coal and natural gas. According to a study published in April in Environmental Research Letters, the ACE rule would lead to 28 percent of the power plants modeled in the study to emit more carbon dioxide by 2030 compared to a scenario with no policy at all.

This rebound effect can also lead to an increase of other air pollutants like particulates, nitrogen oxides, and sulfur oxides. In the EPA’s own regulatory impact assessment for the ACE rule published last year, the agency noted that these extra pollutants could cause between 460 and 1,400 additional deaths per year by 2030, in addition to exacerbating other ailments like asthma.

The ACE rule is part of a concerted, and largely futile, strategy across the Trump administration to boost coal

President Trump has made no secret of his love of fossil fuels in general and coal in particular. His Administration has gone to extreme lengths to boost the sector, from opening up unprecedented amounts of public land to mining to trying to use emergency powers to bail out money-losing coal plants.

The EPA is also working to relax Mercury and Air Toxics Standards that limit hazardous pollution from existing coal-fired power plants. For new coal-fired generators, the EPA is working to relax New Source Performance Standards that govern how much carbon dioxide new power plants are allowed to emit.

The EPA is justifying these changes by arguing that the costs of implementing new environmental controls like scrubbers for flue gases is too high. The agency is also changing how it calculates the benefits of limiting emissions, proposing a shift to a model that yields far fewer saved lives and health benefits.

Scientists on EPA advisory boards who received research grants from the agency have also been forced out of their positions. EPA officials said this was a move to prevent conflicts of interest, but the agency has allowed scientists from industries regulated by the EPA as well as researchers from states that have sued the EPA to continue advising it.

Trump’s EPA has also taken steps to restrict the scientific research it uses to form regulations, arguing that all research that informs rulemaking should be reproducible and make underlying data public. Health advocates say that this would exclude important research on one-off events like chemical leaks, and patient privacy concerns prevent some researchers from releasing their underlying work.

The net result of these changes is a suite of policies that make it easier to keep existing coal power plants online and clear the path for any new plants.

But it’s not regulations that are driving out the coal industry in the United States; it’s competition, especially from natural gas.

Large utility @DukeEnergy, which generates 33% of its electricity from coal, tells me of Trump's ACE rule intended to keep coal plants running longer: "Based on what we know today, we don’t believe the rule will have significant impacts on our business plans for our coal plants" — Joshua Siegel (@SiegelScribe) June 19, 2019

So it’s unlikely that these new rules would move the needle for the coal industry, and more coal-fired power plants are slated to be closed this year.

The Affordable Clean Energy rule obviates one legal headache for the EPA, but is creating another one

Trump’s EPA has argued that the Obama plan exceeded the agency’s authority and that the new proposal fits within the confines of the law. When the CPP was announced, 27 states sued to block it. Then, in an unusual move, the Supreme Court in 2016 ruled 5-4 to stay the Clean Power Plan to allow state lawsuits to proceed, preventing it from ever going into effect.

With the Affordable Clean Energy rule finalized, those lawsuits are now moot.

The latest repeal is at the intersection of two Trump Administration priorities outlined in executive orders: to roll back regulations and to promote US energy development, particularly fossil fuels. And unlike other environmental rollbacks at the EPA that have been delayed, bogged down in bureaucratic muck, or stalled by lawsuits, the ACE rule, now that it has been finalized, might stick.

But New York Attorney General Letitia James has already announced her intent to sue the Trump administration over the ACE rule and expects other states to join the litigation. Other state attorneys general have also come out to oppose the Trump administration’s new power plant rule. That means another wave of court cases could stall the EPA’s new rule.