While the U.S. Environmental Protection Agency (EPA) is in the process of regulating greenhouse gas (GHG) emissions under its Clean Air Act (CAA) authority, Congress has considered several different bills that would preempt CAA regulation of GHGs and replace it with a comprehensive national climate policy. Policymakers should be aware that there are other existing federal statutes granting GHG regulatory authority, and new legislation would likely preempt them as well. This paper surveys these other statutes in order to highlight existing federal authority that might be given up with the passage of a new comprehensive bill. It explores the possibility of direct regulation of GHGs under the Clean Water Act (CWA), along with federal authority to block projects that contribute to climate change under the National Environmental Policy Act (NEPA) and conservation statutes such as the Endangered Species Act (ESA). Newer statutes like the Energy Independence and Security Act (EISA) mandate narrower regulation, but they are also considered here.