Dernbach coauthored an amicus brief to the United States Supreme Court in Massachusetts v. Environmental Protection Agency on behalf of eighteen prominent climate scientists. The brief argued that EPA had mischaracterized or misrepresented the relevant science in deciding not to regulate greenhouse gas emissions from motor vehicles. On April 2, 2007, the Court held that EPA erred by not controlling greenhouse gas emissions. The majority opinion reflects the science described in the brief.
2001 National Academy of Sciences report
In 2001, newly elected President George W. Bush asked the National Academy of Sciences for an assessment of areas of greater and lesser certainty in climate change science. The Academy was chartered by Congress in 1863 to provide scientific and technical advice to the federal government. The Academy, through the National Research Council, responded to the Administration’s request by issuing a report several months later entitled Climate Change Science: An Analysis of Some Key Questions.
The report unambiguously concluded that Earth’s climate is changing in ways that risk significant adverse impacts on public welfare. The report found strong evidence for human causation of recent climate change by emissions of carbon dioxide and other greenhouse gases, and stated that there is a high probability for much larger human-caused climate changes in the future. Finally, the report explained that climate change is likely to have significant adverse effects on U.S. agriculture, water supplies, ecosystems, and coastal areas.
Petition to Regulate Greenhouse Gases from Motor Vehicles
In 1999, a group of 19 organizations filed a petition with the U.S. Environmental Protection Agency asking EPA to regulate greenhouse gas emissions from motor vehicles under the Clean Air Act. While EPA has long regulated other pollutants (hydrocarbons, carbon monoxide, nitrogen oxides) from motor vehicles, it has not regulated the greenhouse gases (such as carbon dioxide) that motor vehicles emit. The petition asserted that greenhouse gas emissions from motor vehicles are significant and present sufficient risks to human health and the environment to warrant regulation under the Clean Air Act. EPA did not immediately act on the petition.
In 2003, EPA denied the petition. EPA claimed that greenhouse gases are not air pollutants under the Clean Air Act. Even if they were air pollutants under the Clean Air Act, EPA said, it would decline to regulate them. Among other reasons, EPA said that climate change science was too uncertain to justify regulation. It cited, as its only source of authority, the 2001 report. EPA used selective quotations from the report to justify its conclusion.
At the Supreme Court
Massachusetts and others challenged EPA’s decision in the U.S. Court of Appeals for the District of Columbia. The Court of Appeals upheld EPA’s decision in a 2-1 decision. Then, at the request of Massachusetts and other petitioners, the Supreme Court decided to hear the case.
Drafting the Amicus Brief
A majority of the scientists who wrote the 2001 report believed that EPA had misrepresented and distorted their work. Prof. Dernbach and three other lawyers, Robert McKinstry, Kirsten Engel, and Stephanie Tai, represented these and other scientists, including two Nobel Prize winners and the head climate scientist for NASA. The central idea of the brief was to allow these scientists to speak directly to the U.S. Supreme Court, in their own words, without filtering, interpretation, or spin.
The brief made three simple points. First, it said that the science of climate change indicates that it is virtually certain that greenhouse gas emissions from human activities cause global climate changes, endangering human health and welfare. Second, it said that EPA mischaracterized the science of climate change, making it appear more uncertain than it actually is. Finally, it said that EPA did not apply the standard of scientific evidence set forth in the Clean Air Act.
A major challenge in preparing the brief was to convince the Supreme Court that the differences between EPA’s interpretation of the report and that of the scientists were not just technical quibbles between experts. If the Court drew that conclusion, EPA would almost certainly prevail on this issue. If, on the other hand, the Court believed that EPA was wrong on the science, the Court would be much more likely to decide the case in favor of Massachusetts and against EPA.
In denying the petition, EPA admitted (1) that “concentrations of GHGs are increasing in the atmosphere as a result of human activities,” (2) that a “diverse array of evidence points to a warming of global surface air temperatures,” (3) that “the magnitude of the observed warming is large in comparison to natural variability.” The brief pointed out that EPA left out the 2001 report’s key determination:
“EPA omitted the essential scientific conclusion that constitutes the core of Climate Change Science: that these separate observations are causally linked. This is a fundamental omission. It is as if a summary of Newton’s Principia—which advanced the theory of gravitation as the common explanation for how apples fall to earth and planets move in the heavens—repeated Newton’s description of the motions of apples and planets, but never got around to mentioning gravity.”
The Supreme Court heard argument in the case on November 29, 2006. At oral argument, the government tried to use the 2001 report to support its position:
- MR. GARRE (representing EPA): And with respect to the scientific uncertainty, Your Honor, you also have to take into account that the EPA had before it and pointed to the report of the National Research Council on global climate change.
- JUSTICE STEVENS: I find it interesting that the scientists who worked on that report said there were a good many omissions that would have indicated that there wasn’t nearly the uncertainty that the agency described.
- MR. GARRE: Your Honor, if you are referring to the amicus brief, Your Honor… I think it is fair for the Court to look at, to look at the document that the agency had before it. That — that document produced by the National Research — Research Council, that’s the research arm of the National Academy of Sciences. And it’s one of the gold standards of research.
- JUSTICE STEVENS: But in their selective quotations, they left out parts that indicated there was far less uncertainty than the agency purported to find.
The Supreme Court’s Decision
The Supreme Court’s 5-4 decision was announced April 2, 2007. The majority opinion, written by Justice Stevens, held that greenhouse gases were air pollutants under the Clean Air Act and that EPA had arbitrarily and capriciously denied the petition. The majority also held that Massachusetts had standing to bring this action.
The opinion is consistent with the views urged by the scientists in the amicus brief. The opinion repeatedly refers to the 2001 report for the scientific support for the proposition that climate change is a serious problem. “The harms associated with climate change are serious and well recognized,” the court says, citing the 2001 report. As if in response to the “Newton argument” in the brief, the court’s opinion begins with these words: “A well-documented rise in global temperatures has coincided with a significant increase in the concentration of carbon dioxide in the atmosphere. Respected scientists believe the two trends are related.”
An amicus brief plays a supporting role, not a lead role, in cases before the Supreme Court. But it appears that this brief helped convince the Court that climate change is a serious problem, and that EPA was wrong about the science. It is therefore likely that this brief contributed in a significant way to the outcome.