initial baseline GHG inventory , we can develop goals to reduce our GHG emissions over time , and actively track progress towards meeting those goals . As we invest more in energy efficiency , begin electrifying aspects of our transportation fleet , and proceed with plans for on-site renewable energy , we believe our emissions will decline in the coming years . In addition , regularly updating our GHG inventory positions the Authority to better address any potential future federal regulations that might require us to track our emissions , and possibly reduce them .
Scope 3 Emissions
For all airports , GHG emissions from Scope 3 activities can represent 80 – 90 % of an airport ’ s total GHG emissions . 50 While these emissions are beyond our direct control , we can assist other stakeholders to reduce these emissions in several ways . One example is working with our concessionaires to reduce their electricity and natural gas use . Other examples include partnering with our airlines on the electrification of their GSE , ensuring we have 100 % ground power and preconditioned air as well as more efficient runway taxiing procedures . Finally , as jet fuel substitutes ( e . g ., biofuels ) become more readily available over time , we can support the integration of these fuels into our fueling supply network .
Greenhouse Gas Inventory Results
Our partner , NREL , has completed initial GHG inventories for Dulles International , Reagan National , and the DTR , using primarily 2018 as the baseline year ( see full inventory results for additional information ). These inventories have been developed with the best available data and as a result , there are certain gaps in the analyses that we intend to fill over time . Examples of these gaps for the two airports include fuel use for firefighting training , chemicals used for fire suppression , and fuel use for airport-owned auxiliary power units and GSE ( if any ). Regardless , we are comfortable that we have captured the primary sources of Scope 1 and Scope 2 emissions ( which do not include tenant or airline emissions which are considered Scope 3 emissions ) for these initial inventories . Over time , we will improve our data collection processes so that subsequent GHG inventories minimize any uncertainties reflected in this initial effort .
Summary Results
As is shown in Figure 7 , on a combined basis , our facilities ( excluding tenants and airlines ) are responsible for approximately 123,500 MT of CO 2 e on an annual basis . Given its larger size , Dulles International emits roughly 3 times more GHGs than Reagan National on an absolute basis . However , when the GHG emissions are normalized by building gross floor area ( MT CO 2 e per thousand gross square feet ), the airports ’ GHG emissions profiles are comparable . On a standalone basis , the DTR ’ s annual GHG
Figure 7 : Annual metric tons of CO 2 e 50 Volpe Center Report for the FAA Office of Airport Planning ( 2016 ). U . S . Airport Greenhouse emitted by Gas Authority Emissions facilities
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