This report is a guide for airports that wish to reduce or eliminate greenhouse gas (GHG) emissions from existing buildings and operations. Reaching carbon neutrality typically requires the use of multiple mechanisms to first minimize energy consumption and then maximize renewable energy use. This report provides a flexible, step-by-step outline for planning and achieving airport carbon emissions reduction or neutrality. The steps include: (1) Conducting background research and inventorying airport GHG emissions; (2) Determining the scope of the carbon neutral airport project; (3) Contracting with an energy services company (ESC); (4) Implementing renewable energy; and (5) Communicating project results.