In the absence of legislative action on climate change by the federal government and many states, a number of proponents of reducing greenhouse gas emissions have turned to the courts. In the case of American Electric Power Co. v. Connecticut, the U.S. Supreme Court recently heard oral arguments about whether common law nuisance claims may be brought against power companies for their greenhouse gas emissions. The author discusses oral arguments in the case and argues that, however the court may rule, the decision could be one of the most important in the field of environmental law because it touches on so many legal areas. In addition, the author says the court’s ruling in AEP could have significant effects on several other climate change-related cases pending in federal courts.