Last week, a global panel of climate scientists released a report of their latest findings on the state of climate change. The report is the first of a number that will be released through early 2014 by the Intergovernmental Panel on Climate Change (IPCC), a UN body that issues an scientific assessments on climate change. The latest report establishes that carbon emissions since the beginning of the Industrial Revolution must remain at or below one trillion metric tons in order to avoid the most dangerous effects of climate change. At current energy consumption rates, the trillionth ton of carbon is expected to be burned off around 2040.
The IPCC’s findings bear significantly on environmental litigation in federal courts. The Environmental Protection Agency (EPA) and other federal agencies have drawn heavily from the IPCC’s findings to promulgate new regulations and actions related to greenhouse gas emissions and climate change. In turn, litigants have either referenced the IPCC’s findings to challenge agency decisions or questioned the agencies’ reliance on IPCC findings.
For example, litigants recently referenced the IPCC in a challenge to the Fish and Wildlife Service’s (FWS) listing of polar bears as a “threatened” species, but not “endangered.” In listing polar bears as threatened but not endangered, the FWS found that due to the effects of climate change, the polar bear “is likely to become an endangered species within the foreseeable future.” Litigants argued, inter alia, that the FWS’s decision was arbitrary and capricious because the FWS adopted the IPCC’s definition of “likely,” but failed to incorporate this definition in its assessment of the polar bear. The D.C. Circuit disagreed, finding that the FWS’s reference to the IPCC’s definition of “likely” pertained to the likelihood of climate change events occurring, not the likelihood of polar bears becoming extinct.
Last year, litigants claimed that uncertainty over the IPCC’s climate science rendered invalid the EPA’s finding that greenhouse gases threatened public health and welfare in Coalition for Responsible Regulation v. EPA. They argued, inter alia, that the EPA improperly “delegated” its judgment to the IPCC by relying on its assessments of climate-change science. The D.C. Circuit disagreed. In upholding the EPA’s findings regarding greenhouse gases and its regulation of them, the court found that the EPA properly relied on the IPCC’s findings on climate change: “This is how science works. [The] EPA is not required to re-prove the existence of the atom every time it approaches a scientific question.”
The Supreme Court was scheduled to consider certiorari on Coalition v. EPA this past Monday. Petitioners argue that the EPA fails to show how its regulation of greenhouse gas emissions will reduce global atmospheric concentrations and therefore benefit public health and welfare. If the Justices grant certiorari, the IPCC’s latest assessment on climate change will once again be an important component of amici briefs and parties’ arguments. The government will likely draw on the IPCC’s newer findings regarding the need for regulation to link emissions regulation to public health and welfare benefits. Petitioners will likely argue that although the IPCC’s newest findings indicate that greenhouse gas emissions must be reduced to avoid long term climate problems, they still do not establish the link between domestic regulation and measurable or meaningful public benefit.