COMMISSION 
AGENDA MEMORANDUM                        Item No.          10c 
BRIEFING ITEM                            Date of Meeting      October 26, 2021 
DATE:     September 17, 2021 
TO:        Stephen P. Metruck, Executive Director 
FROM:    Arlyn Purcell, Director, Aviation Environment & Sustainability 
Jon Sloan, Director, Maritime Environment & Sustainability 
Sandra Kilroy, Sr. Director, Environment, Sustainability & Engineering 
SUBJECT: Carbon Emissions and Accelerating Century Agenda Objectives 
EXECUTIVE SUMMARY 
This briefing will present the Port of Seattle's (Port) annual greenhouse gas (GHG) emissions 
inventory, carbon reduction initiatives, and potential impacts of revising Port GHG goals to be
more aggressive.  Staff will present data showing that port-wide Scope 1&2 GHG emissions
have decreased approximately 20  percent  through 2020 largely due to carbon-reduction
strategies.  We anticipate achieving a 50 percent reduction at end of 2021 due to RNG at the
airport. Alternatively, for Aviation Scope 3 emissions are generally on the rise, but due to the
COVID-19 pandemic decreased by 35 percent from the average of the previous five years.
Maritime Scope 3 emissions decreased 20 percent in 2016 from 2005 levels due to new
international and national regulations, increased use of shore power by cruise vessels,
improved vessel and equipment efficiency, replacement of older equipment, and use of cleaner
maritime fuels. Both Divisions are implementing GHG reduction plans with some initiatives
currently underway. 
Given the urgency of the climate crisis and the Port's desire to transform operations to 
eliminate GHG emissions, the Executive Director is proposing to accelerate our GHG reduction
objectives. Changing the Scope 1&2 reduction goal from carbon neutral or negative by 2050 to
net zero or better by 2040 could increase costs for both Aviation and Maritime divisions due to
the compressed implementation schedule. Neither Division anticipates substantial impacts
from increasing the Scope 3 goal from 80 percent to carbon neutral by 2050 since the key
strategies to reduce those emissions would largely stay the same.
BACKGROUND 
The Port conducts GHG emissions inventories on an annual basis for both SEA and the Maritime 
and Economic Development Divisions  (Maritime/EDD). Port inventories follow  the GHG
Protocol Corporate Accounting and Reporting Standard to estimate: 


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COMMISSION AGENDA  Briefing Item No. 10c                                 Page 2 of 7 
Meeting Date: October 26, 2021 
(1)   Scope 1&2 emissions from sources directly or indirectly controlled by the Port such as
electricity use, fuels for Port-owned vehicles, and natural gas for heating Port facilities; 
and, 
(2)   Scope 3 emissions from sources under Port influence such as aircraft, ships, and
passengers traveling to and from SEA. 
Most of Scope 1&2 emissions are from heating and cooling Port facilities and fueling Port fleet
vehicles.  These emissions are quantified annually, as are Scope 3 emissions from aviation
sources. Scope 3 Maritime/EDD emissions from cruise, grain and commercial fishing operations 
are quantified every five years through the Puget Sound Maritime Air Emissions Inventory. The
Port's Scope 3 Maritime/EDD GHG emission totals do not include emissions from marine cargo
terminals controlled  by the Northwest Seaport Alliance (NWSA), which are inventoried 
separately. 
GHG EMISSION TRENDS, 2005-2020 
As  shown  in  Figure 1  below, Port-wide  Scope 1&2  GHG  emissions have  decreased
approximately 20 percent as of 2020 compared to the 2005 baseline due to a combination of
factors. These include using renewable natural gas (RNG) Q4 2020 in SEA boilers and bus fleet,
joining Puget Sound Energy's Green Direct electricity program, and using renewable diesel in
aviation and maritime fleet vehicles and equipment. 
Changes to operations in response to the  COVID-19 pandemic contributed  to  decline in
emissions from maritime fleet vehicles and natural gas use at maritime properties. However,
natural gas use increased at SEA during COVID-19 as more heating was required as fewer
passengers occupied the Terminal. 
Figure 1. Port-wide Scope 1&2 emissions 







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COMMISSION AGENDA  Briefing Item No. 10c                                 Page 3 of 7 
Meeting Date: October 26, 2021 
Scope 3 emissions for Aviation decreased by 35 percent in 2020 since 2015 due to the COVID19
pandemic that dramatically reduced air travel. This also reduced emissions from related
ground transportation and tenant operations. However, Scope 3 emissions steadily increased
prior to 2020 due to increasing demand for air travel and associated services. 
While Maritime Scope 3 emissions aren't quantified annually, emissions in 2020 declined
significantly as well since COVID-19 led to the cancellation of the 2020 cruise season. Cruise
calls account for approximately 70 percent of the Port's maritime Scope 3 emissions. Prior to
COVID-19 and as of the last Maritime scope 3 inventory for the year 2016, Maritime-related 
Scope 3 emissions 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. 
CURRENT INITIATIVES 
Both the Aviation and Maritime/EDD divisions are implementing GHG reduction plans with
many initiatives and some currently underway. 
Aviation Division 
Key Aviation Division reduction efforts include: 
(1)   Signing a 10-year contract in Q2 2020 to supply renewable natural gas (RNG) to fuel
both the boilers and Rental Car Facility (RCF) bus fleet at SEA 
(2)   Using renewable diesel in diesel fleet vehicles 
(3)   Procurement of Green Direct electricity for our Puget Sound Energy electricity accounts 
Also, staff are partnering with both internal and external experts including the National
Renewable Energy Laboratory (NREL) to evaluate  alternatives for updating  the  central
mechanical plant with low-carbon fuels and advanced technologies. Similarly, Aviation's
Facilities and Infrastructure team continues to implement energy saving projects throughout
the Terminal including lighting and HVAC upgrades. 
In addition, the Aviation Division continues to develop partnerships and initiatives to reduce
Scope 3 emissions such as advocating for policies (e.g., Clean Fuels Standard) in Washington,
reducing  aircraft  APU  run-times,  and  conducting  economic  and  technical  research  on
infrastructure needs, feedstock availability, and production facility costs for sustainable aviation
fuel (SAF).
Lastly, the Aviation Division is developing several initiatives to reduce carbon emissions from
passenger vehicles driving to and from SEA.  These include working with NREL to evaluate 
access fees, evaluating policy incentives to encourage GT service providers  (e.g., taxis,
transportation network companies or TNCs and airporters) to transition to electric vehicles and

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COMMISSION AGENDA  Briefing Item No. 10c                                 Page 4 of 7 
Meeting Date: October 26, 2021 
use renewable fuels, working with King County Metro on digital ticketing for transit, and
installing EV charging stations across SEA facilities. 
Maritime and Economic Development Division Initiatives 
Key Maritime/EDD GHG reduction efforts include implementing the objectives within the 2020
Northwest Ports Clean Air Strategy (NWPCAS) and the strategies in the Port's implementation
plan, Charting the Course to Zero: Port of Seattle's Maritime Climate and Air Action Plan 
(MCAAP). 
The MCAAP identifies emission reduction actions by 2025 and by 2030 for each source of
maritime-related emissions to achieve a 50 percent reduction in GHG emissions by 2030 and
remain on course to phase out seaport-related emissions by 2050. Key commitments include: 
(1)   Continuing to engage and form partnerships with community, industry, and government
to reduce emissions 
(2)   Transitioning  100%  of  Port-owned  light-duty  vehicles  to  electric  models  or  use
renewable fuels 
(3)   Eliminating fossil natural gas use in Port-owned buildings 
(4)   Installing shore power at all cruise ship berths 
(5)   Reaching 100% of homeport cruise ship calls connecting to shore power 
(6)   Addressing  key  constraints  to  deploy  infrastructure  for  zero-emissions  equipment,
locomotives,  vehicles,  vessels,  and  building  through  the  completion  and  early
implementation of the Seattle Waterfront Clean Energy Strategy (SWCES). 
UPDATING GHG REDUCTION OBJECTIVES 
The Port's current and proposed Century Agenda greenhouse gas reduction objectives are the
following: 
Current                             Proposed 
Scope 1&2          15% below 2005 levels by 2020    15% below 2005 levels by 2020 
Port Directly and    50% below 2005 levels by 2030     50% below 2005 levels by 2030 
Indirectly             Carbon neutral by 2050 OR          Net-zero or better by 2040 
Controlled             Carbon negative by 2050 
Emissions 
Scope 3             50% below 2007 by 2030           50% below 2007 by 2030 
Port Influenced      80% below 2007 by 2050           Carbon neutral or better by
Emissions                                                     2050 
To recognize the urgency of action needed to address climate change, Port staff recommend
the Port Commission support  updating the greenhouse gas reduction objectives  to the
following: 
(1) Accelerate the Port's Scope 1&2 emission reduction efforts by 10 years to be net-zero or
better by 2040 instead of carbon neutral by 2050. 

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COMMISSION AGENDA  Briefing Item No. 10c                                 Page 5 of 7 
Meeting Date: October 26, 2021 
(2) Increase the magnitude of the Port's Scope 3 objective to be carbon neutral by 2050
instead of an 80 percent reduction below 2007 by 2050.
The term net-zero is proposed to bring the Port in line with international carbon accounting
definitions, and in keeping with the Port's emphasis on minimizing the use of offsets to
eliminate in-sector emissions. Net-zero means that any greenhouse gases released into the
atmosphere from an organization's activities are balanced by an equivalent amount being
removed.1 Carbon neutral is slightly different, whereby emissions can be offset with a reduction
that includes buying carbon offsets to make up the difference. Given the Port's limited ability to
directly reduce these emissions, we recommend  the additional flexibility carbon neutral
provides for the Scope 3 objective. 
For Aviation, the potential budget impacts for moving the Scope 1&2 year from 2050 to 2040
and changing to net zero are expected to be relatively small.  This is because the main
strategies discussed above require significant investments well before 2040 to align scheduled
asset management and replacement with the transition to low-carbon technologies and fuels.
For example, fleet vehicles are typically replaced within 12 to 15 years,  and Aviation's
Maintenance Department will replace many if not most fleet vehicles with EVs by 2040.
Similarly, the Airport is currently conducting the Utility Master Plan to meet future utility
demands including a review of its central mechanical plant (CMP).  Recommended updates to
the CMP will include low-carbon strategies that can reasonably expected to be implemented
prior to 2040. 
There may be a 5-year interval between 2040 and 2045 when some small portion of the Port's
electricity supply would not yet be net zero carbon. The Clean Energy Transformation Act
(CETA) requires all electrical utilities in Washington to be net zero carbon (100% clean) by 2045.
For that five-year period, the Port could purchase Renewable Energy Credits (RECs) for this
small portion of electricity as a means of achieving the goal rather than building on-site
renewable sources. 
The Aviation team is already moving in this direction with many projects underway. Although
there will be some cost increases due to compressing the implementation schedule, it is
unlikely that moving the goal up by ten years will change the budget dramatically.  However,
the Port will need to commit financial and other resources to ensure the organization remains
on track to meet its goals. 
For Maritime and EDD, given that the Port's Maritime/EDD emissions have increased in recent
years, achieving an accelerated GHG reduction target of net-zero Scope 1&2 GHG emissions by
2040 will require several conditions and significant additional effort. 
1 There is no global shared definition of net zero, but SEA (along with airports worldwide) uses the distinction that carbon
neutral allows for offsets, whereas net zero does not. The World Economic Forum defines the terms differently; our draft text 
includes the WEF definition. In addition, SEA adopts and follow what ACI World has stated that matches the WEF definition
(https://aci.aero/wp-content/uploads/2021/06/LTCG-FAQ.pdf). 

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COMMISSION AGENDA  Briefing Item No. 10c                                 Page 6 of 7 
Meeting Date: October 26, 2021 
(1)   Accelerate the elimination of fossil natural gas heating ventilation and cooling (HVAC) 
systems in port-managed properties and at all port properties. 
(2)   Purchase renewable natural gas for HVAC and Domestic Hot Water systems within their
useful life or prohibitively expensive to electrify. 
(3)   Purchase renewable electricity from Seattle City Light and/or invest in additional onsite
renewable energy production ahead of the CETA deadline. 
(4)   Accelerate implementation of the Sustainable Fleet Plan to deploy EV charging across
waterfront properties and purchase electric vehicles. 
The Maritime team expects that changing the GHG targets will result in significant new urgency
to prioritize capital projects with carbon reduction opportunitieswhich in today's market,
without a uniform price on carbon, come at an incremental price above the conventional
approach. Accelerating decarbonization will put pressure on the capital budget immediately
and the Port must not forgo any opportunities to eliminate emissions as they arise in the annual
budget. Under the Sustainable Evaluation Framework, this may mean prioritizing approaches
and technologies that eliminate emissions over options that may carry a lower cost but also
lower emissions reductions. In addition to capital expenditures, achieving the goals 10 years
earlier will likely require additional staff support or increased use of outside services. 
Scope 3: Potential impacts of accelerating from 80% to carbon neutral or better by 2050 
For Aviation, the potential impacts of shifting from 80 percent to carbon neutral by 2050 for
Scope 3 for Aviation do not reduce or increase the challenges. Scope 3 emissions are outside
the Port's direct control, and it is difficult to predict future technologies and behavior for the
main sources of emissions: aircraft and on-road vehicles. Still, the Port can continue to reduce
emissions by: 
(1)   Advocating for state and national policies that strengthen tailpipe standards for carbon 
emissions, support initiatives to require all vehicles sold in the U.S. to be EV and install
charging infrastructure. 
(2)   Increasing  environmental  performance  requirements  for  Transportation  Network
Companies  (TNCs)  and  taxis  through  service  agreements  and  expand  those
requirements to all ground transportation providers at SEA. 
(3)   Continuing to lead in developing Sustainable Aviation Fuel (SAF) although feedstocks for
this fuel may be limited, particularly as those feedstocks compete with other on-road
renewable fuels (e.g., renewable diesel).
Electric- and/or hydrogen-powered aircraft are being developed on a global scale and might
replace some regional aircraft travel by 2050.  It is difficult at this time to predict, much less
plan for, the airport of the 2050s. Urban air mobility concepts such as electric air taxis could
complicate emissions forecasts. In addition, electric and autonomous surface vehicles could
change vehicle ownership and use substantially. The Port will continue to track industry trends
and significant developments, and signal when it makes sense to bring in resources to identify
future scenarios, analyze potential impacts on resources, and plan for changes in capital and
operating budgets. 

Template revised September 22, 2016.

COMMISSION AGENDA  Briefing Item No. 10c                                 Page 7 of 7 
Meeting Date: October 26, 2021 
For Maritime,  the impacts of changing the Scope 3 goal are not significant since  the
Commission has already adopted the 2020 NWPCAS  vision to phase out seaport-related
emissions by 2050. Accelerating the Port's Scope 3 goal would help align the Century Agenda
GHG targets with the NWPCAS vision. Much of the Port's ability to reach this target rests with
the private sector and the Port's ability to continue to form partnerships with other ports,
governments, and industry both nationally and globally. Specifically, the Port can influence
maritime-related Scope 3 emissions by: 
(1)   Completing the installation of shore power at Pier 66 and working with the cruise lines
to reach 100 percent of homeport cruise ships equipped with shore power by 2030 and
a 100 percent connection rate. 
(2)   Completing and implementing the Seattle Waterfront Clean Energy Strategy, which will
create a roadmap to decarbonize maritime operations in Seattle. 
(3)   Engaging at the national and international levels to strengthen standards to support
sustainable maritime fuels and the transition to zero-emission technologies. 
(4)   Implementing green leasing policies that incorporate sustainability best practices into
landside leases. 
ATTACHMENTS TO THIS BRIEFING 
(1)   Presentation slides 
PREVIOUS COMMISSION ACTIONS OR BRIEFINGS 
June 9, 2020  The Commission approved adoption of Resolution No. 3775 (item 6i.) 
establishing the Century Agenda Policy Directive. 
October 24, 2017    The Commission approved  a motion (item 6b.) implementing
recommendations of the Energy and Sustainability Committee and setting strategic
greenhouse gas reduction priorities to add Scope 2 GHG reduction goals to the Century
Agenda. 
April 11, 2017  The Commission approved a motion (item 6e.) to amend the Century
Agenda greenhouse gas reduction goals to adopt more stringent goals of 15% below
2005 levels by 2020, 50% below 2005 levels by 2030, and carbon neutral or carbon
negative emissions by 2050 for Scope 1; and 50% below 2007 levels by 2030 and 80%
below 2007 levels by 2050 for Scope 3. 





Template revised September 22, 2016.