Understanding Our Emissions
Seattle releases an analysis of our climate pollution, called a greenhouse gas inventory, every two years. See the tabs below for more context on why this work is important, what our recent analysis is telling us, and the action steps we are committed to. A downloadable version of our most recent report is here.
The City recently released the 2019 Consumption-based Emissions Inventory (CBEI). A downloadable version of the report is available here.
Overview
A greenhouse gas (GHG) is a gas in the atmosphere that traps and holds heat. When we use the phrase greenhouse gas emissions, we are talking about the gasses that are released into the atmosphere primarily as a result of human activities. The more GHGs we release, the more our climate is impacted. We measure our greenhouse gas emissions using a geographic-based emissions inventory to better understand the scope and scale of our local climate footprint, the impact of our actions, opportunities for progress, and the challenges ahead.
The Seattle GHG inventory tracks emissions over three key sectors: transportation, buildings, and waste for a total of over 3 million metric tons of climate pollution emitted and transportation continuing to account for the majority of core emissions. As our population and economy continue to grow, we need to take bolder steps to become a sustainable, healthy, and climate friendly city.
2020 Update
The 2020 GHG Inventory finds a marked decrease in greenhouse gas emissions since the prior 2018 report, the majority of which are likely temporary and primarily attributed to the impacts of the COVID-19 pandemic.
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Transportation (24.5% decrease in emissions)
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Seattle’s residents drove significantly less in 2020 primarily due to COVID-19 stay-at-home orders, resulting a 20% decrease in both passenger and freight vehicle miles traveled (VMTs).
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Public transit was especially hard hit, and traffic monitors show vehicle volume and personal vehicle travel patterns returning back to baseline.
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The 2020 GHG inventory also showed a 5% decrease in emissions per mile, a trend that is likely to continue as vehicles on the road will continue to get gradually more efficient.
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Buildings (5% decrease in residential and commercial emissions)
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All core building emissions categories decreased except for residential (3% increase), which accounts for the increase in time spent at home as residents who were able adhered to stay-at-home orders and continued working from home.
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At the same time, Seattle’s buildings also got more efficient, consuming 5% less energy per capita after normalizing for weather, a trend that is expected to continue, and Seattle City Light's emissions factors changed as the utility reported a resource portfolio with less carbon-intensive electricity compared to 2018.
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As with transportation emissions, commercial building emissions are expected to rebound in consequent years.
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Waste (12.4% decrease in emissions)
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The major factors contributing to the reduction in waste emissions were a decrease in commercial waste due to the pandemic, and a new residential waste composition study, which shows a lower percentage of recyclable and compostable materials entering the waste stream.
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Waste emissions account for just 1.2% of total core emissions in this geographic-based emissions inventory, but SPU’s consistent efforts to improve the composition of municipal solid waste have led to a 35.5% reduction in emissions since 2008.
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Climate Justice
Climate change is a racial justice issue. Seattle's increasing consumption of fossil gas is harming all of our communities. Yet, we know that our Black, Indigenous, and People of Color (BIPOC) communities are being impacted disproportionately. These communities unequally bear the burden of climate change, air pollution, and environmental degradation.
While our current climate analysis provides us a broad understanding of how our emissions are trending, it is not detailed enough in scope or depth to use as the primary source for making decisions that center racial equity. It is therefore imperative that we center this context when analyzing the results of this inventory and prioritize partnering with BIPOC communities to shape equitable climate policy for the City.
As called for in the Green New Deal Resolution (Res 31895) to address these gaps, OSE is developing a map-based website which will be updated on a quarterly basis to provide more frequent and granular data indicators of emissions in Seattle’s neighborhoods. The “One Seattle Climate Portal” will be released by the end of 2022. Beginning in 2023 the City will develop the next phase of the portal which will incorporate community led data efforts, as well as ways to spatially track city-led investments.
Climate Data Visualizations
All of our inventory data is now available to explore through the dashboards below. The first dashboard displays data on overall emissions trends since the baseline year of 2008. The second dashboard contains a detailed breakdown of emissions by sector, sub-sector, source, and fuel type.
If the dashboards are not displaying correctly in your browser click these links to open in a new tab:
Difference between Core and Expanded emissions: Core emissions include the transportation, buildings, and waste sectors. Core emissions sources are those the city can most directly and significantly impact. Expanded emissions include all core emission sectors as well as additional sectors that the City has less direct influence over.
We measure and track Seattle's greenhouse gas (GHG) emissions on a regular basis. These reports identify the source and amount of climate pollution across the city of Seattle.
Consumption-based Emissions Inventory
Overview
The City of Seattle has developed a consumption-based emissions inventory (CBEI) which estimates the greenhouse gas (GHG) emissions associated with all the goods and services consumed within the community, no matter where they are produced (including the extraction of raw materials, manufacturing, and global transportation). This inventory looks at all of the emissions associated with the food we eat, the things we buy, how we travel, and the homes we live in.
Results
The CBEI analysis shows that in 2019, the typical Seattle household was responsible for roughly 33 metric tons of CO2e annually (MTCO2e), or about 16 MTCO2e per person. For context, 33 MTCO2e is equivalent to 7 gasoline-powered passenger vehicles driven for one year. With 343,988 households in the city, this is a total of roughly 11 million MTCO2e in 2019 attributable to residents of Seattle.
City of Seattle Consumption-based Emissions Inventory, 2019
Among the 135 neighborhoods or census tracts within the city, there is substantial variation in the key driving demographic variables and hence in consumption-based emissions. The highest-emitting neighborhood has per-household emissions of 59 MTCO2e, while households in the lowest-emitting neighborhood have emissions of 17 MTCO2e – roughly a 3-fold difference.
Consumption-based emissions map (MTCO2e per household)
Action
The City of Seattle is committed to addressing consumption-based emissions, and this inventory is an important first step.
- Under the framework of the One Seattle Climate Justice Agenda, Seattle is investing to support policies and programs aimed at building an equitable clean energy economy, ensuring a just transition away from fossil fuels, and building healthy and climate resilient communities.
- Seattle is also building toward an inclusive circular economy, where all materials, water, and resources are valued, and nothing is wasted.