The emerging market for greenhouse gases, developed over the past five years, has been driven partly by ongoing international global climate change treaty negotiations. It is likely that this treaty will impose limitations on greenhouse gas emissions. Successful emissions trading programs have been established over the past ten years, including the sulfur dioxide trading program incorporated into the U.S. Clean Air Act Amendments (CAAA) of 1990. These successful emissions trading programs have shaped the market. This paper discusses: (1) initiatives and programs that have produced a framework for early policy and trades development; (2) characteristics of the emerging market for greenhouse gases and major features of early negotiations; (3) how the ongoing concurrent international and domestic climate change policy development will lead to a potential evolution of the market; and (4) possible scenarios of the U.S. response to climate change.