Flipping Daubert: putting climate change defendants in the hot seat.

• Author: Hackney, Ryan
• Position: NOTES

1. INTRODUCTION II. WHAT SCIENTIFIC DISPUTES ARE LIKELY TO EMERGE IN CLIMATE CHANGE LITIGATION? III. DAUBERT AND FEDERAL RULE OF EVIDENCE 702--JUDGES AS GATEKEEPERS IV. HOW CLIMATE CHANGE PLAINTIFFS CAN USE DAUBERT TO EXCLUDE DEFENSE EXPERT TESTIMONY A. Challenging the Wither--Can a Weatherman Predict the Climate? B. Challenging Reliability: How Many Peers Does It Take to Review a Paper? C. Challenging Relevance: Plants May Love C[O.sub.2], But So What? D. Challenging Conclusions: If a Glacier Grows in Greenland, Is Climate Change Debunked? V. CONCLUSION I. INTRODUCTION

   Can plaintiffs in climate change lawsuits use the Daubert standard to exclude testimony by defense experts? Since the United States Supreme Court announced the standard in Daubert v. Merrell Dow Pharmaceuticals, Inc., (1) it has been used almost exclusively to the benefit of defendants. (2) There is no theoretical reason, however, why plaintiffs could not use Daubert challenges to exclude testimony by defense witnesses in a scientific field in which the great weight of scientific research supports the plaintiffs' claims. It is likely that in many cases climate change litigation will present such a situation. An overwhelming body of evidence now supports the conclusions that human activities are increasing atmospheric levels of greenhouse gases (GHGs), that these increased levels of GHGs are leading to warming of the atmosphere, and that this warming will have widespread effects on climate. (3) This Note refers to those conclusions and the research behind them as the consensus model. In recent years, parties opposed to GHG regulations have attacked the consensus model in the public arena and In the political process with scientific assertions that could probably not withstand a Daubert challenge in the courtroom. (4) This Note examines how such assertions might arise in the litigation process, and considers four ways in which plaintiffs may use the Daubert standard and the Federal Rules of Evidence to exclude and restrict defense testimony: challenge the witness, challenge the reliability of the evidence, challenge the fit of the evidence to the case, and challenge the conclusions a witness may draw from otherwise admissible evidence.

   Part II of this Note examines the field of climate change litigation and considers the kinds of scientific disputes that are likely to arise in future litigation. Part III looks at the Daubert standard and Rule 702 of the Federal Rules of Evidence. Part IV applies the Daubert standard to actual cases of "experts" and scientific assertions that prominent climate change skeptics have publicly advanced in the debate over climate change. Part V considers what conclusions can be drawn from this analysis, both for the future of climate change litigation and for the broader public debate over climate change.

   This Note suggests that Daubert challenges by climate change plaintiffs can have significant effects in three ways. First is the impact on climate change litigation itself. Daubert challenges will most likely allow plaintiffs to exclude experts, evidence, and conclusions from the courtroom that climate change skeptics have been able to advance successfully in the public arena. By excluding evidence of dubious reliability and relevance, these challenges will focus the courtroom debate on the actual scientific issues involved, and could be enormously valuable to plaintiffs in establishing the legal elements of their claims. The second impact is on other types of litigation. Although Daubert challenges have in the past been employed primarily by defendants, (5) the successful use of Daubert challenges by plaintiffs in climate change litigation could provide a blueprint for evidentiary challenges by plaintiffs in other fields of scientifically complex litigation.

   The third impact, and perhaps the most significant, is that changing the debate inside the courtroom may alter the debate outside the courtroom as well. A central conclusion of this Note is that many of the scientific claims advanced by climate change skeptics in the public arena and in the political process would not even be admitted into a courtroom. If this conclusion is correct, it suggests that there is something inadequate in the way the political process addresses scientifically complex issues, and that perhaps the Federal Rules of Evidence present a superior means of analyzing at least certain types of scientific disputes. While a reform of the evidentiary practices of government is beyond the scope of this Note, this Note does suggest that a clearer focus on the actual scientific issues of climate change within the courtroom may help focus the debate outside of the courtroom as well. Even if every climate change plaintiff loses his or her case, climate change litigation may still have beneficial consequences if these lawsuits can help steer the national discourse away from spurious debates over uncertainty and toward an honest evaluation of what is going on and what we can do about it.

2. WHAT SCIENTIFIC DISPUTES ARE LIKELY TO EMERGE IN CLIMATE CHANGE LITIGATION?

   This Note is based on three premises: first, that plaintiffs will continue to bring climate change lawsuits; second, that some will successfully make it to trial; and third, that a direct conflict over the science of climate change will eventually emerge in the courtroom. Regarding the first premise, much has been written about climate change lawsuits that have been filed and that could theoretically be filed. (6) There are a huge number of obstacles that climate change plaintiffs win need to surpass in order to reach trial, including establishing a duty (7) and surmounting such jurisdictional bars as standing, preemption, and political question. (8) This Note assumes that some plaintiffs will be able to surpass such obstacles to reach the point where a challenge to scientific evidence will be relevant. If climate change lawsuits reach that stage, it seems inevitable that some will wrestle with the scientific evidence for the biggest climate change questions: Is it happening? What is causing it? What changes will it bring to how people live, and what can we do to slow it down or adapt to it?

   Given the early stage of this novel litigation, cases so far have focused more on questions of standing rather than the scientific issues involved. The first climate change lawsuit brought on the common law action of public nuisance was Connecticut v. American Electric Power Co. (9) The state of Connecticut brought this case against five public utility companies, seeking caps on carbon emissions by the defendants as well as a schedule for future reductions. (10) The United States District Court for the Southern District of New York dismissed this case in 2005 as a nonjusticiable political question before any scientific evidence could be presented. (11) On September 21, 2009, however, the Second Circuit vacated the lower court's decision and determined that the political question doctrine did not bar consideration of the case; the case has been remanded to the district court to hear the nuisance claims. (12) Another high-profile public nuisance case that the court dismissed at the district level on political question and standing grounds prior to any debate over scientific evidence was Comer v. Murphy Oil USA, (13) in which the court dismissed nuisance claims brought by victims of Hurricane Katrina alleging that the GHG emissions of the defendant oil and gas companies exacerbated the damage caused by the hurricane. (14) In a decision that surprised many observers, on October 16, 2009, the Fifth Circuit partially reversed the district court in Comer, ruling that the plaintiffs had standing to bring claims for nuisance, trespass, and negligence, and that the political question doctrine did not bar these claims. (15)

   The courts dismissed on political question grounds two prominent cases in California. In California v. General Motors Corp., (16) a public nuisance claim seeking damages from several automakers on behalf of the people of California, the district court dismissed the case without prejudice as a nonjusticiable political question. (17) Another intriguing case is Kivalina v. ExxonMobil, (18) a suit brought by an Inupiat village in Alaska against ExxonMobil and other energy industry companies alleging that the defendants' activities have contributed to rising sea levels in the Arctic that have threatened the existence of the coastal village. (19) The U.S. District Court for the Northern District of California dismissed the case on September 30, 2009, on political question and standing grounds. (20) The Ninth Circuit has not yet issued an opinion in either of these cases; it remains to be seen whether the Ninth Circuit will join the Second and Fifth Circuits in holding that the political question doctrine does not bar consideration of climate change tort claims.

   The administrative law cases that have addressed climate change so far have likewise avoided much debate on the scientific evidence for climate change. While administrative law cases are not subject to Daubert and the Federal Rules of Evidence, and are therefore outside of the main scope of this Note, (21) they do help make up the backdrop of climate change litigation in which common law actions proceed. The most influential of these cases so far, and the only climate change lawsuit heard to date by the U.S. Supreme Court, was Massachusetts v. Environmental Protection Agency (Massachusetts v. EPA). (22) In this case, a group of states brought suit to compel the Environmental Protection Agency (EPA) to regulate carbon dioxide (C[O.sub.2]) as a pollutant under the Clean Air Act (CAA). (23) The court determined that C[O.sub.2] is a pollutant as defined by the CAA. (24) Although the Court did not specifically command EPA to regulate C[O.sub.2], it did state, "EPA can avoid taking further action only if it determines that greenhouse gases...