Keeping below the Tipping Point: A Literature Review of Climate Change with Attention to NEPA

The courts are increasingly finding that National Environmental Policy Act (NEPA) documents need to address climate change impacts-both the impact of the project on climate change and the impacts of climate change on the project. In the scientific arena, the year 2007 was pivotal in climate change because the Fourth Assessment Report of the United Nations Intergovernmental Panel on Climate Change ( IPCC) was issued. The IPCC report concluded that warming of the climate system is unequivocal and that this warming is primarily caused by increases in greenhouse gas concentrations. To address the issue and its impacts on a given project, policy, or program for a NEPA review, the analyst is presented with the difficulty of summarizing a massive amount of literature from the earth, biological, and physical sciences. This article provides a summary of the recent literature, addressing the IPCC report, the evidence for climate change, effects in different regions, NEPA implications, and mitigation strategies. NEPA reviews in the area of infrastructure in coastal regions and in the area of water supply will need special attention in light of climate change. All of this will make for much decision making under uncertainty, but ultimately NEPA documents and environmental decisions are likely to benefit from consideration of climate change because more resilient projects are likely to be approved, even if climate change is not as intense as some estimates. This article emphasizes NEPArelevant events and is not intended to provide details on the current regulatory framework under other laws.