Recent presidential executive orders have mandated federal agencies, including the Department of Defense, to disclose and reduce their own greenhouse gas (GHG) emissions, and to reduce emissions through the procurement process by including reporting requirements for federal contractors. In November 2022, federal agencies began the rulemaking process to amend the Federal Acquisition Regulation. The proposed change would require significant contractors to use existing, non-governmental standards in their GHG disclosures. This paper outlines key terms, standards, and issues associated with GHG accounting and reporting, as well as identified areas for further research.