Q+A: Are We Planning to Fail by Repealing the Clean Power Plan?

Shannon Capps, PhD, directs the Atmospheric Air Modeling Lab at Drexel.

The Environmental Protection Agency is taking steps to repeal the Clean Power Plan, an Obama Administration initiative intended to curtail greenhouse gas emissions so that the nation could reach the emissions benchmarks set forth in the Paris Agreement on Climate Change. While the CPP, was introduced just two years ago and has been in the court system ever since, the goals it put forward have already led to broad changes in energy sourcing and emissions regulations in many states. Experts who have studied the CPP believe that a replacement would struggle to achieve similar emissions goals or realize the same health benefits.

Shannon Capps, PhD, an assistant professor in Drexel’s College of Engineering, is one of those experts. Capps has been working with a group of environmental engineering researchers to project the effect of the emissions reductions that would have been created by the CPP. While the group recently suggested that any replacement for the plan would likely do more harm than good, Capps also took a deeper look at the residual impact of the Plan and laid out what the near-term regulatory landscape for greenhouse gas emissions could look like post-CPP.

Critics of the Clean Power Plan contend that the federal government was overstepping its authority to regulate energy utilities. What are some examples of “inside-the-fence-line” vs. “outside-the-fence-line” measures and why might the former be considered less burdensome to utility providers than the latter?

“Inside the fence line” measures would include improving the efficiency of coal power plants. While these costs would be incurred by the power plant owner/operator and the utility provider, they would also be at liberty to pass along those costs to consumers.

“Outside the fence line” measures could include government investment in energy efficient technology, akin to the ENERGY STAR rating program, in order to reduce the demand for energy or introduction of a trading system for carbon dioxide emissions that crosses state boundaries. Perhaps the introduction of economic externalities that would shift the market, that is,  motivations for people to buy less of their product or additional costs for producing electricity, are perceived as burdensome to utility providers.

energy guide
“Outside the fence line” measures could include incentivizing the use of energy efficient appliances.

Many recent executive orders have had the effect of delegating to states the responsibility for making laws and regulations to replace the ones repealed at the federal level. How do you see this playing out with regard to the repeal of the Clean Power Plan? 

Many states were motivated, by monetary efficiency or political will, to transition to wind or solar resources for power prior to the announcement of the CPP. These states will likely continue with plans that keep the fraction of power produced through coal relatively low, though some locations will not have the same incentives. The latter category is where the most emissions changes due to the CPP repeal can be expected.

Research from my colleagues at Syracuse University suggests that the alternative approach that EPA is expected to introduce, known as “inside the fence line improvements,” will only slightly reduce greenhouse gas and nitrogen oxide emissions but may raise sulfur dioxide emissions.

How could the court system factor into the EPA’s new provisions for greenhouse gas emissions regulations that would replace the Clean Power Plan?

What parameters/limits does the EPA need to operate within when crafting a replacement for the CPP?

Although the new administration has flexibility to direct agencies to change course, the courts act as a check to ensure that the substance behind the decision making remains consistent. Specifically, when the EPA acts to protect human health and public welfare, as Congress has authorized and required it to do, current science informs the regulation, which is typically challenged in the legal system.

The EPA issued the Clean Power Plan in response to decisions in court that implicated carbon dioxide in harming human health and public welfare. The decision will likely be finally affirmed or denied in the judicial branch.

Though the administration is taking steps to pull us out of it, what does all this mean for the U.S. meeting the emissions reductions goals set forth in the Paris Agreement?

It could have quite an impact if we hope to reach the emissions reductions goals we agreed to in Paris. Looking at environmental models with conditions similar to the CPP, we see a reduction in carbon dioxide emissions by more than 23 percent by the year 2020. By contrast, Driscoll’s model suggests that using “inside the fence line” alternatives, which could be proposed in place of the CPP, would only reduce emissions by slightly over 2 percent.

Because carbon dioxide emissions from the power sector make up a significant portion of America’s greenhouse gas emissions, the projected difference of 20 percent is substantial.


Shannon Capps leads the Atmospheric Modeling Lab at Drexel where she studies the impact of pollutants, including fossil fuel and aerosol emissions.

For media inquiries contact Britt Faulstick, bef29@drexel.edu or 215.895.2617