About the Port's Greenhouse Gas Emissions Inventories
The Port conducts two separate greenhouse gas (GHG) emissions inventories: one for GHG emissions associated with the Seattle-Tacoma International Airport (SEA) and the other for GHG emissions from its maritime-related sources, which include the Port's Maritime and Economic Development Divisions' lines of business separate from SEA. Both Port inventories follow the GHG Protocol Corporate Accounting and Reporting Standard to estimate Scope 1, Scope 2, and Scope 3 emissions, which represent sources directly and indirectly controlled or under some degree of Port influence.
Inventories track progress toward the Port's Century Agenda GHG reduction targets. In October 2021, the Port updated its GHG targets to accelerate Scope 1 & 2 reductions to net zero or better by 2040 from carbon neutral or negative by 2050, and increase ambition of its Scope 3 reductions to carbon neutral or better by 2050 from 80 percent. The updated targets respond to the urgency of the climate crisis, build on reduction initiatives already underway, and affirm Port leadership to facilitate the clean energy transition and zero-emission port operations.
| Scopes 1 and 2 | Scope 3 |
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| Port-controlled and Port indirect emissions | Emissions the Port has influence over but not direct control |
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(1) Net-zero means any carbon dioxide released into the atmosphere from a company’s activities is balanced by an equivalent amount being removed
(2) Carbon neutral or carbon negative means emissions can be offset with a reduction that could include buying carbon offsets to make up the difference
The SEA GHG Emissions Inventory is verified by the Airport Carbon Accreditation Program. The Port's Maritime GHG Inventory is newer and not yet verified, but the Port may seek verification for future maritime inventories. Port of Seattle conducts GHG emissions inventories annually for the previous calendar year. Starting with the year 2019, historical and prior year inventory results will be publicly posted online each year as soon as the inventory process is complete. The Port is committed to data accuracy and transparency and the inventories represent a best estimate of emissions sources. As new information or inventory best practices become available, the Port may update historical data or inventory methods to better reflect its sources and their contributions.
Port-Wide Greenhouse Gas Emissions
Scope 1 and 2 GHG Emissions
Scope 1 and 2 emissions include direct emissions from sources under the Port's control (scope 1) or indirect emissions produced to generate the electricity used by the Port (scope 2). The Port conducts inventories for Scope 1 and 2 emissions annually.
| Scope 1 Sources | Scope 2 Sources |
|---|---|
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Trends
The Port of Seattle cut emissions from its own operations by 46 percent in 2021 over 2005 baseline. The Aviation Division became the first major operating division to meet the Port’s ambitious goal to reduce owned and controlled emissions by 50 percent by 2030. The massive reduction came almost entirely from the purchase of renewable natural gas produced from landfill waste.
Aviation Scope 1 and 2 Details
SEA Airport Scope 1 and 2 GHG emissions in 2021 decreased 50 percent from the 2005 baseline of 23,106 metric tons of CO2, meeting the Port’s Century Agenda 50 percent reduction goal eight years early.
- Replaced fossil natural gas with renewable natural gas in our boilers for heating fuel and in our bus fleet.
- Used renewable diesel in our fleet.
- Purchased PSE Green Direct wind electricity for buildings on the south end of the airport.
Maritime Scope 1 and 2 Details
Maritime and Economic Development Division Scope 1 and 2 GHG emissions in 2021, 2,200 metric tons of CO2, decreased 2 percent from the 2005 baseline of 2,255 metric tons, reversing a pre-pandemic trend of increases. Emissions prior to the pandemic in 2019 had increased by 12 percent over the 2005 baseline.
- GHG emissions from fuel use in maritime vehicles and equipment declined 41 percent since 2005 due to renewable diesel and lower gasoline use since pre-pandemic levels (2019).
- The reduction in gasoline use is likely due to fewer in-person meetings and less utilization of the motor pool as telework continued, as well as ongoing efforts to right-size the fleet and retire older, less efficient vehicles.
Impact of COVID
COVID related changes in travel did not influence the outcome of the airport’s emission reduction results. While airport passenger volume recovered to just 85 percent of pre-pandemic travel, operations to run buildings and vehicle fleets were quite close to pre-pandemic levels. Impacts of the pandemic continued to be felt on the Maritime and Economic Development Division, particularly with lower natural gas use at waterfront properties, fewer cruise calls with a shortened season, slower bookings at Port-owned conference facilities, and reduced employee usage of fleet vehicles.
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SEA Airport Scope 1 and 2 Emissions Inventory Data (2021) |
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Port of Seattle Maritime Scope 1 and 2 Emissions Inventory Data (2021) |
Scope 3 GHG Emissions
Scope 3 GHG emissions are indirect sources of emissions that are a consequence of the Port's activity but are owned or controlled by another entity. Scope 3 emissions sources include energy used by Port tenants, airplanes, ground transportation to and from the airport, cruise ships and other ocean-going vessels, cargo-handling equipment, rail locomotives, waste transport and disposal, employee business travel by air, and even Port employees commuting to and from work.
Trends
The COVID-19 pandemic dramatically reduced air travel. As a result, Scope 3 emissions for Aviation decreased by 35 percent in 2020 compared to 2015. Decreased air travel also reduced related emissions from ground transportation and tenant operations. However, Scope 3 emissions steadily increased prior to 2020 due to increasing demand for air travel and associated services.
GHG emissions from maritime supply chain (ocean-going vessels, commercial harbor vessels, recreational vessels, locomotives, cargo-handling equipment, cruise buses on terminals) are not quantified annually. GHG and air emissions from these sources are quantified every five years through the Puget Sound Maritime Air Emissions Inventory. While the Port does not have GHG data for these sources in 2020, GHG emissions associated with the maritime supply chain declined significantly from the cancellation of the 2020 cruise season in response to COVID-19.
Prior to COVID-19 and as of the last Maritime scope 3 inventory for the year 2016, Maritime-related Scope 3 emissions had declined 20 percent since 2005. This decline was largely due to new international and national regulations, such as the North American Emissions Control Area, increased use of shore power by cruise vessels, improved vessel and equipment efficiency, and successful port policies and programs that encouraged replacement of older equipment and use of cleaner maritime fuels.
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SEA Airport Scope 3 Emissions Inventory Data (2020) |
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Port of Seattle Maritime Scope 3 Emissions Inventory Data* |
*Note: Data on GHG emissions from maritime supply chain (ocean-going vessels, commercial harbor vessels, recreational vessels, locomotives, cargo-handling equipment, cruise buses on terminals) comes from the Puget Sound Maritime Air Emissions Inventory. Completion of this inventory occurs every 5 years and is complex as the Port does not own or manage the vessels and equipment. The 2020 Maritime Scope 3 Emissions data uses 2016 GHG emissions levels for maritime supply chain sources because 2016 is the most recent year that data from these sources is available. The next Puget Sound Maritime Air Emissions Inventory will be complete for year 2021.
