DC appeals court rejects attacks on EPA’s greenhouse gas Endangerment Finding

Posted on July 18, 2012


Part two of a series.

On June 26, 2012, a three judge panel of the DC Court of Appeals ruled against 26 legal petitions by states and industry groups that had sought to overturn the Environmental Protection Agency’s (EPA’s) greenhouse gas (GHG) regulations. The Court’s Opinion (hereafter “the Opinion”) found that “the Endangerment Finding is consistent with the Massachusetts v. EPA and the text and structure of the CAA, and is adequately supported by the administrative record. [emphasis original]”

The Opinion focused on three main arguments made by the petitioners. The first, discussed below, was that the EPA erred when it found that GHGs were a “reasonable threat to public health and welfare” as defined by the Clean Air Act (CAA in quotes from the Opinion). In the Opinion, the appeals court found that the EPA had correctly interpreted the Clean Air Act, that it had adequately supported the Endangerment Finding that led to the regulations, that the EPA did not have to quantify the risks of climate change in a finding of endangerment, that the EPA was not necessarily required to submit the Endangerment Finding to the EPA’s own Science Advisory Board in this case, and that the EPA acted properly in rejecting several petitions to reconsider the Endangerment Finding.

The other two arguments that the Court rejected – that the Clean Air Act was being misused by the EPA and that the Tailoring Rule focusing on large emitters first ran contrary to the Clean Air Act – will be addressed later in this series.

The EPA properly interpreted the endangerment finding standard

According to the states and industry groups (aka “the petitioners” in the Court Opinion) asking the Court to overturn the Endangerment Finding, the EPA wrongly interpreted Section 202(a)(1) of the Clean Air Act, the section that applies to motor vehicle-emitted air pollutants. The industry groups asserted that the EPA had to take into account such things as the benefits of actions that emit GHGs such as electricity generation and concrete production. They also asserted that the effectiveness (or lack thereof) of regulations should be considered, as well as the ability of society to adapt or mitigate climate change.

But the Court strongly disagreed, writing that “These contentions are foreclosed by the language of the statute and the Supreme Court’s decision in Massachusetts v. EPA. [emphasis original]” According to the Opinion, the motor vehicle pollution section needs only two answers: “whether particular ‘air pollution’ – here, greenhouse gases – ‘may reasonably be anticipated to endanger public health or welfare,’ and whether motor-vehicle emissions ’cause, or contribute to’ that endangerment.” In this case, the EPA found that the answer to both question was “yes.”

Beyond the Clean Air Act, however, Massachusetts v. EPA also found that the EPA was not allowed to include policy considerations in a scientific decision, a fact the DC Court pointed out. As the Court wrote, these policy exercises “do not inform the ‘scientific judgment’ that [the Clean Air Act] requires of EPA.”

As the Court wrote, “The statute speaks in terms of endangerment, not in terms of policy, and EPA has complied with the statute.”

The EPA based the Endangerment Finding on solid scientific ground

The Court also found unconvincing the assertions made by industry groups that the scientific evidence supporting the Endangerment Finding was inadequate. The Opinion says that “The body of scientific evidence marshaled by EPA in support of the Endangerment Finding is substantial,” an observation that adds legal weight to the overwhelming scientific evidence that climate disruption is occurring.

In support of that general statement, the Opinion also points out that the EPA

found that extreme weather events, changes in air quality, increases in food- and water-borne pathogens, and increases in temperatures are likely to have adverse health effects. The record also supports EPA’s conclusion that climate change endangers human welfare by creating risk to food production and agriculture, forestry, energy, infrastructure, ecosystems, and wildlife. Substantial evidence further supported EPA’s conclusion that the warming resulting from the greenhouse gas emissions could be expected to create risks to water resources and in general to coastal areas as a result of expected increase in sea level. Finally, EPA determined from substantial evidence that motor-vehicle emissions of greenhouse gases contribute to climate change and thus to the endangerment of public health and welfare.

According to the Opinion, the EPA based all those findings on three lines of evidence. First, the physics of the climate system and how the globe is warming even though orbital and solar forcing should be cooling the global climate. Second, the historical record of how the modern global average temperature is hotter than at any point in the last 400 years and, in many places, since 900 AD. And third, detailed simulations that show how modern temperatures can only be replicated by including agricultural and industrial GHG emissions (lower graph at right).

While the Opinion did acknowledge that some uncertainty does exist in the science, it also found that the “existence of some uncertainty does not, without more, warrant invalidation of an endangerment finding.” And when weighing the arguments presented by the petitioners against the Endangerment Finding, the Court found that the petitioners failed to show that there was more than “some residual uncertainty” in the scientific basis underlying climate disruption.

The Court ultimately rejected the petitioners’ implied demand that the Court “re-weigh the scientific evidence,” saying that it was not their place to do so.

The EPA need not quantify the the risks of an air pollutant

The next question that the Court had to answer was whether or not the Clean Air Act required the EPA to quantify the risk and thresholds beyond which GHG emissions became a threat to the health and welfare of the United States and her citizens. This argument was put forward by various states, led by Texas, who claimed that “without defining these thresholds and distinguishing ‘safe’ climate change from climate change that endangers, EPA’s Endangerment Finding is just a ‘subjective conviction.'”

But the Court found that this was a significant misreading of the Clean Air Act by the states. Contrary to the states” assertion, the Opinion stated that the Clean Air Act “necessarily entails a case-by-case, sliding-scale approach to endangerment.” Furthermore, the Court found that “Texas’s call for quantification of the endangerment is no more than a specialized version of Industry Petitioners’ claim that the scientific record contains too much uncertainty to find endangerment.”

And given the Court rejected the industry groups’ uncertainty-based argument, the states’ similar argument was understandably rejected as well.

The EPA did not have to submit its finding to its Science Advisory Board

When the EPA submits its rules and findings to other Federal agencies for official review and comment, it’s supposed to submit those rules and findings to an in-house Science Advisory Board (SAB). In the case of the GHG Endangerment Finding, the EPA did not submit the finding to the SAB at the same time it submitted the finding to the Office of Information and Regulatory Affairs for “an informal review process [emphasis original]” as required by Executive Order 12866. Industry groups contended that the Finding should be overturned because the EPA failed to do this.

The Court disagreed, pointing out that the industry groups failed to respond to the EPA’s claim that the review under Executive Order was merely informal. The Opinion also said that, even if the industry groups had shown that the EPA failed to follow its own procedures in this case, the industry groups had not demonstrated that this error was “of such central relevance to the rule that there is a substantial likelihood that the rule would have been significantly changed if such errors had not been made.” And since they’d failed to meet this criteria, the Court would not overturn the Endangerment Finding based on this argument.

The EPA sufficiently justified its refusal to reconsider the Endangerment Finding

The last claim made by the states against the EPA regarding the Endangerment Finding was that the EPA should not have denied all 10 petitions to reconsider the Finding. The Opinion lists some of the reasons that the states provided in those 10 petitions:

According to EPA, the petitioners’ claims based on the CRU documents were exaggerated, contradicted by other evidence, and not a material or reliable basis for questioning the credibility of the body of science at issue; two of the factual inaccuracies alleged in the petitions were in fact mistakes, but both were “tangential and minor” and did not change the key [Intergovernmental Panel on Climate Change] IPCC conclusions; and the new scientific studies raised by some petitions were either already considered by EPA, misinterpreted or misrepresented by petitioners, or put forth without acknowledging other new studies.

Essentially, the EPA rejected the 10 petitions because they cherrypicked data and scientific papers, misread the hacked CRU emails (aka Climategate), and misrepresented the state of science as described in the Fourth Assessment Report of the IPCC. And the Court agreed, finding that the states had not “provided substantial support for their argument that the Endangerment Finding should be revised.”

With respect to the IPCC, the states claimed that there was non-peer reviewed information included in the assessment reports, but the Opinion writes that the states “ignore[d] the fact that (1) the IPCC assessment relied on around 18,000 studies that were peer-reviewed,” and that the IPCC permitted the use of non-peer reviewed studies. Furthermore, as the Opinion says,

State Petitioners have not, as they assert, uncovered a “pattern” of flawed science. Only two of the errors [in the IPCC reports] they point out seem to be errors at all, and EPA relied on neither in making the Endangerment Finding. [emphasis added]

With respect to other errors that the states claimed to have found, the Opinion says that the states “failed to show that these isolated “errors” provide substantial support for their argument to overturn the Endangerment Finding.”

The Court found the arguments made by the state and industry groups to be wholly without merit. The Court disagreed with states and industry groups who claimed that the EPA misread the Clean Air Act. The Court disagreed with industry groups who claimed that there was too little known about the science of climate change to make an accurate finding. The Court disagreed with states claimed that the EPA was required to quantify the threshold beyond which climate change and greenhouse gas emissions becomes a threat. The Court said that it didn’t matter whether the EPA failed to send the Endangerment Finding to its own Science Advisory Board or not. And the Court disagreed with industry groups who claimed that the EPA should have reconsidered the Endangerment Finding.

In essence, the DC Circuit Court of Appeals found that the greenhouse gas Endangerment Finding was exactly what the EPA said it was – based on sound scientific evidence and anchored firmly within the legal requirements of the Clean Air Act.


Arbitrary: A decision that was made without regard for facts or circumstances and with a disregard for evidence (source).
Capricious: A decision that was made based on what the decision maker wanted to do, rather than what the evidence said was appropriate (source).
Endangerment Finding: According to Section 202(a)(1), the Administrator of the EPA is mandated to regulate any air pollutant that “in his judgment cause[s], or contribute[s] to, air pollution which may reasonably be anticipated to endanger public health or welfare.” When an air pollutant is identified as endangering public health or welfare, that’s an “endangerment finding.” In the case of this and related articles, the “Endangerment Finding” is the EPA’s finding that a combination of six greenhouse gases in particular qualify as an air pollutant as defined by the Clean Air Act.
Petition/Petitioner(s): A request to the Federal Courts for redress of grievances is known as a “petition,” and the term comes from the First Amendment of the United States Constitution. A “petitioner” is an individual, state, or organization that has petitioned the government for redress of grievances.
Standing: This is the law doctrine that states that only people who have been injured in some way have the right to sue for damages or changes to the law. Individuals who do not have a stake in the outcome of the suit are not permitted to enter into a lawsuit because they lack “standing.” For much more information, please see the definition at the Free Dictionary’s Legal Dictionary.

Image Credits:
United States Court of Appeals for the District of Columbia Circuit
Intergovernmental Panel on Climate Change