A Case Study in Scientific Integrity: The Science Behind Greenhouse Gas Emission Standards

September 27, 2011 | 11:40 am
Supreme court
Francesca Grifo
Former contributor

Last week, the administration delayed the release of a proposed rule on the regulation of global warming emissions from power plants. This came on the heels of a decision to withdraw a science-based standard for ground-level ozone pollution.

In the face of industry pressure for even more delays—and to weaken the Clean Air Act—it’s worth examining the robust scientific standards the EPA adheres to in its attempts to protect public health. A good case study is the EPA’s handling of the scientific evidence that supports regulation of greenhouse gases.

The negative effect of air pollution on health has been well established within public health science. (There are literally thousands of peer reviewed articles on the subject, but for those looking to be convinced, check out a fascinating study that took place during the 1996 Atlanta Olympics. The study makes a powerful argument for the negative impact of vehicle emissions on health: reductions in commuting and traffic during the Olympics correlated with a 47 percent decrease in acute asthma events at a downtown hospital.)

Despite the increasing evidence of the harmful health effects of greenhouse gas emissions, it wasn’t until April 2007 that these emissions were formally recognized as pollutants and subject to regulation under the Clean Air Act. The story of the EPA’s quest to protect the public from these emissions—and industry’s resistance—spans both the George W. Bush and Obama administrations.

United States Supreme Court

The Supreme Court in 2007 ordered the EPA to consider whether greenhouse gases from new motor vehicles endanger public health and welfare. Photo: Flickr/dbking.

The EPA’s mandate

In a landmark 2007 case, Massachusetts v. EPA, the U.S. Supreme Court ruled that greenhouse gases are in fact air pollutants under Section 202a of the Clean Air Act, and could be subject to regulations – if the EPA found that the science showed the emissions to be harmful. The Court then tasked the EPA with determining whether or not emissions of greenhouse gases from new motor vehicles cause or contribute to air pollution which may reasonably be anticipated to endanger public health or welfare. The court gave the EPA significant leeway as to how to make this determination, stating only that the reason for the so called “endangerment finding” was to “conform to the authorizing statute.”

The undertaking was unprecedented: the EPA had never before been tasked with putting together an endangerment finding for any other pollutant. What followed was an exhaustive review of the scientific literature.

EPA’s analysis relied on peer-reviewed science

Following the Supreme Court ruling, the EPA established a group of senior scientists to weigh the scientific evidence and make one of three determinations: find that motor vehicle greenhouse gas emissions may “endanger public health or welfare” and issue emission standards; find that they do not pose a public health threat; or find that climate change science is sufficiently uncertain as to preclude making a finding either way. (An endangerment finding would be a legal prerequisite to proposing greenhouse gas emission standards.)

Of course, it was essential for the EPA to rely on peer-reviewed science when making its determination. Fortunately, the data EPA considered in making the endangerment finding were already extensively peer-reviewed. The Agency examined peer-reviewed studies included in the 2007 Intergovernmental Panel on Climate Change (IPCC) report; four reports by the National Research Council, a division of the U.S. National Academy of Sciences; 18 federal government studies; and the international Arctic Climate Impact Assessment. (A description of these entities’ peer-review structure and a listing of the data and findings considered by EPA can be found on pages 3-4 of the endangerment finding). Throughout the process, the science used to determine the health hazards of greenhouse gases underwent extensive internal and external review.

The agency faces resistance to action

In December 2007, just 6 months after the Supreme Court ruling, the EPA sent the first draft of the endangerment finding to the White House, but faced fierce resistance from the White House. Incredibly, the White House Office of Management and Budget under President Bush refused to open an email from the EPA containing the endangerment finding so the administration would not have to take action on it. As a result, this document was not publically circulated and did not undergo formal inter-agency review.

The EPA continued to move forward, however, and in July 2008, the agency issued an Advanced Notice of Proposed Rulemaking on an updated draft of the endangerment finding and submitted the document for inter-agency review and public comment.

In December 2009, after years of data analysis, two public hearings, and the assessment of more than 500,000 comments, the EPA released a final endangerment finding. Written by 30 EPA senior scientists, and reviewed by experts in seven agencies, the final document definitively states that greenhouse gases endanger the public health and welfare of Americans.

Ten groups – including the Competitive Enterprise Institute, U.S. Chamber of Commerce, Peabody Energy, and politicians acting on behalf of Texas and Virginia—petitioned the agency to drop the finding. Those petitions attacked the science underlying climate change and the agency’s process for handling the science.

EPA, however, had done its homework. In July 2010, the agency formally rejected those petitions, arguing that the objections petitioners raised were erroneous and that the agency had adequately responded to the concerns raised during its comment period for the new rules.

But in the months since, several (so-far unsuccessful) proposals have been put forward in Congress to strip EPA of its authority to regulate greenhouse gases, and members of Congress have attempted to cast doubt on the credibility of the EPA’s analysis.

Careful consideration is key

The development of greenhouse gas emissions standards illustrates how the scientific process plays a key role in developing effective rules and policies, and how scientific integrity is the cornerstone of many rules that protect health and safety. The EPA is trying to put forth science-based policies to protect public health. We can only hope that politics won’t continue to get in its way.

**UPDATE, SEPTEMBER 28: Today, an EPA inspector general (IG) report was made public confirming that the EPA followed the rules to ensure adequate peer review and scientific integrity when preparing the endangerment finding. “EPA met statutory requirements for rulemaking and generally followed requirements and guidance related to ensuring the quality of the supporting technical information,” wrote the IG.

After reading the report, I put out this statement.

I also found interesting this timeline of the EPA’s endangerment finding on the agency’s website that has a short chronology of events leading up to the finalization of the finding. For those who want to get fully into the weeds, EPA has a helpful series of fact sheets and a frequently asked questions document.