A Federal Court has recently thrown open the door to potential civil challenges to both private and governmental sources of greenhouse gas emissions, based on the Federal common law of nuisance. For those who believe the Environmental Protection Agency (EPA) has acted too slowly in promulgating greenhouse gas regulation, civil actions are now possible at least in the Second Circuit. However, the Supreme Court may now scrutinize the Second Circuit’s decision. Based on a recent Fourth Circuit decision on a similar issue, the “Nine” may be tempted to follow in Moses’ footsteps and pare down the Second Circuit decision to apply only to greenhouse gas emissions from Federal projects.