Underpinned by an in-depth longitudinal case study research design, this study examines FrankfurtAirport's annual carbon dioxide (CO2) emissions as well as the methods and technologies that have been implemented to reduce the environmental impact of carbon dioxide (CO2) emissions at the airport. The study period was from 2008 until 2019. The study's data was examined by document analysis. Frankfurt Airport's total annual carbon dioxide (CO2) emissions increased from 1,653,658 tonnes in 2008 to 1,744,201 tonnes in 2019. Frankfurt Airport's annual climate gas intensity of traffic performance ratio largely displayed a downward trend decreasing from a high of 3.4 kg CO2 per traffic unit in 2009 to 1.5 kg CO2 per traffic unit in 2019. Despite the strong traffic growth in passenger traffic, the airport's annual direct carbon dioxide emissions per traffic unit largely exhibited an overall downward trend, declining from a high of 0.51kg CO2 per traffic unit in 2010 to a low of 0.41kg CO2 per traffic unit in 2019. The airport's annual indirect carbon dioxide emissions per traffic unit decreased from a high of 2.88 kg CO2 per traffic unit in 2009 to a low of 1.46 kg CO2 per traffic unit in 2019. Frankfurt Airport has implemented extensive carbon dioxide (CO2) reduction measures which include the hydraulic balancing of heating systems, upgrading windows and doors, optimizing lighting, air conditioning and heating systems, optimizing the energy usage of the airport's baggage handling system, the use of highly efficient LED lighting, the use of low emission vehicles, the electrification of ground service equipment, the optimization of energy usage in all new buildings at the airport, and the planned widespread use of renewable energy sources (wind and solar power).