In Massachusetts v. EPA, 127 S. Ct. 1438 (U.S. 2007), the U.S. Supreme Court held that the Clean Air Act authorized the Environmental Protection Agency (EPA) to regulate greenhouse gas emissions from new motor vehicles—despite the EPA's contrary claim—and that Massachusetts had standing to challenge the EPA's denial of a rulemaking petition to promulgate such regulations. The case appears to have exposed many businesses to potential liability for personal injuries and property damage claims based upon the emission of greenhouse gases. A major issue that these potential claims raises concerns the source of funds to provide indemnity and costs of defense. A comprehensive general liability (CGL) policy is the principal insurance policy implicated, but the policy's pollution exclusion may bar coverage. On the other hand, the insured's reasonable expectation for coverage of such claims may be determinative.