A June white paper from the Texas Public Policy Foundation (TPPF) has found that carbon dioxide (CO₂) emissions from the U.S. power sector do not meet the threshold set under the Clean Air Act (CAA) to be considered a significant contributor to air pollution that endangers public health.

Under Section 111 of the CAA, the U.S. Environmental Protection Agency (EPA) does not have the authority to regulate emissions from a particular source unless that source “contributes significantly” to air pollution that puts public health at risk. However, EPA has ruled with its 2009 “Endangerment Finding” that the current and projected concentrations of CO₂, along with five other greenhouse gases in the atmosphere—methane (CH₄), nitrous oxide (N₂O), hydrofluorocarbons (HFCs), perfluorocarbons (PFCs), and sulfur hexafluoride (SF₆)—threaten public health and the welfare of current and future generations.

As TPPF points out, “unlike the criteria pollutants regulated under the Clean Air Act, CO₂ is not directly harmful to humans. In fact, it is essential to all life, being an output of the respiration process of all humans and animals and an input to photosynthesis. CO₂ levels would need to reach 20 to 30 times the current concentration in the atmosphere in order to have a negative impact on oxygen levels and respiration. Therefore, the impact of CO₂ on the public health hinges on its effect upon global temperatures and the resulting impacts on global weather and climate.”

The United States was responsible for only 13 percent of global CO₂ emissions from fossil fuels in 2023, TPPF notes, a decline from 24 percent of global emissions in 2000. Further, CO₂ emissions from fossil-fuel-based electricity generation comprised only four percent of global emissions from that sector, a number that is also declining.

Highlighting that decline is the May release of the U.S. Energy Information Administration’s (EIA) annual U.S. Energy-Related Carbon Dioxide Emissions report, which has found, once again, that natural gas continues to be at the forefront in the decline of GHG emissions in the United States.

According to the report, power sector CO₂ emissions remained near their 2023 levels in 2024, even with a three percent increase in electricity generation.

“Although overall electricity generation increased by 3 percent, or 122 terawatt hours (TWh), in 2024, changes in generation sources resulted in sectoral CO₂ emissions remaining near 2023 levels,” EIA states. “Although growth in natural gas-fired generation exceeded reductions in coal-fired generation, CO₂ emissions did not increase as much because natural gas emits less CO₂ per kilowatt hour than coal when combusted.”

Further, the supplemental report appendix and methodology shows that natural gas is responsible for 61 percent of the power sector’s emissions reductions since 2005.

The EIA report is just one in a string of recent of studies showing how natural gas has had a significant impact on the reduction of GHG emissions in the United States.

A study from researchers at Miami University in Ohio, published in the peer-reviewed journal Energy Economics in May, found that between 2007 and 2019, the fracking-induced shale boom was responsible for an average annual per capita reduction in CO₂ emissions in the United States of 10.5 percent, as well as a 7.5 percent reduction in annual total GHG emissions.

“We find that the shale gas boom has played a pivotal role in reshaping the U.S. energy landscape, resulting in a greener economy,” the researchers conclude.

In January, the U.S. Department of Energy’s National Energy Technology Laboratory found the GHG emission intensity of the country’s energy profile had decreased by 32 percent between 2017 and 2020.

In determining the future long-term effects of U.S. CO₂ emissions, TPPF utilized the Model for the Assessment of Greenhouse Gas Induced Climate Change. This model was “used to predict future global CO₂ concentrations and temperatures in a scenario that eliminates U.S. CO₂ emissions,” with its baseline a “middle of the road” scenario that has been used by the Intergovernmental Panel on Climate Change (IPCC) in various assessments.

This model showed “eliminating U.S. power sector CO₂ emissions by 2030 would reduce the worldwide CO₂ concentrations in 2050 by 3.4 ppm, or 0.7%, and reduce the increase in mean worldwide surface temperature in 2050 by 0.015 °C. On the other hand, eliminating all U.S. CO₂ emissions by 2030 would reduce worldwide CO₂ concentrations in 2050 by 11.4 ppm, or 2.3%, and reduce the increase in mean worldwide temperature in 2050 by 0.052 °C. Note that the measurement error and annual variation in the mean worldwide surface temperature is approximately ±0.1 °C… Therefore, the modeled temperature increase due to future U.S. CO₂ emissions—which is itself subject to large uncertainties—is not measurable in the worldwide context, as the modeled impact falls within the measurement error for global temperatures.”

Fortunately, EPA director Lee Zeldin has announced the agency’s decision to rescind the Endangerment Finding after a public comment period that runs through September 15. Members of both of President Donald Trump’s administrations have consistently stated that regulation of carbon dioxide under the Clean Air Act is unnecessary, ineffective, and economically destructive. They also claim that as long as the Endangerment Finding remained in place, efforts to effectively roll back unnecessary environmental regulations adopted in the name of fighting climate change and intended to punish conventional energy producers would likely have failed.

Unfortunately, the actions of the executive branch seem to be in a permanent state of uncertainty, as incoming administrations from opposing political parties and governing ideologies seek to quickly undue the actions of their predecessors they think were not in the public interest. Without action from the legislative branch, there is always the possibility of the return of the Endangerment Finding as early as 2029. Therefore, Congress should recognize that the regulation and taxation of carbon dioxide is against the public good, and pass legislation banning such practices. This is the only true way to ensure against the return of a zombie Endangerment Finding somewhere in the future.

Heartland Impact can send an expert to your state to testify or brief your caucus; host an event in your state; or send you further information on a topic. Please don’t hesitate to contact us if we can be of assistance! If you have any questions or comments, contact Cameron Sholty, at csholty@heartlandimpact.org or 312/377- 4000.