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.


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 to better understand the scope and scale of our local climate footprint, the impact of our actions, opportunities for progress, and the challenges ahead. 

Seattle's historical climate leadership has resulted in progressive energy efficiency policies and a robust public transit network which in turn has helped us achieve one of the lowest per-person GHG emissions rates compared to North American peer cities. What this shows is that our climate actions started us off in the right direction. However, today we are far off the pace needed to meet our climate goals. 

As our population and economy continue to grow, we need to take bolder steps to become a sustainable, healthy, and climate friendly city. Subsequent climate pollution reductions will have to come primarily from eliminating fossil fuel use through electrifying our buildings and vehicles.  

Recent Update

  • Since our last report in 2016, Seattle's overall GHG emissions have increased 1.1%. While we have reduced our overall emissions by 4.1% since 2008, that reduction is not nearly enough to meet our climate goals.
  • GHG emissions from the building sector increased 8.3% since our last report, largely as a result of growing fossil gas use. Gas that is used for cooking, space and water heating in buildings is a fossil fuel and its extraction, storage, and combustion releases methane, a potent greenhouse gas. Fossil gas is responsible for 86% of all residential and commercial building emissions. 
  • Transportation is Seattle's largest source of climate emissions--responsible for 60% of Seattle's GHG emissions. Much of that comes from passenger cars and trucks. Transportion emissions declined 2.4% between 2016 and 2018, but the emissions reductions in this sector will need to be much greater going forward. 

Climate Justice

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. 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. 

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. 

Staff Contact: 
Ani Krishnan, Climate Data & Policy Manager

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.  

To expand the data dashboards to full screen, click on the "pop out" button (diagonal line with arrows on each end) on the bottom far right of the dashboard.

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.

Seattle's Near-Term Climate Action Steps

The City is currently addressing both energy efficiency and building emissions through strong energy codes, Seattle City Light incentives, and through energy benchmarking and mandatory tune-ups in existing buildings. We are seeing the positive impact of these policies on participating buildings in reduced energy use and GHG emissions. Continued action to address climate change while advancing equitable solutions are being pursued by the following initiatives:

  • Seattle Energy Code: The first step in addressing building-related emissions is to stop increasing emissions from fossil gas in new construction. The proposed update to the Seattle Energy Code would require clean electric heating and hot water systems in new commercial and multifamily buildings. 
  • Clean Heat Program: Heating oil is the least efficient, most expensive, and most polluting form of home heating in Seattle. In order to reduce climate pollution, prevent soil and groundwater contamination, and improve air quality, Seattle has passed a law to help phase out oil heat by 2028. Rebates are currently available for residents to switch from oil heat to energy-efficient heat pumps.  
  • Building Performance Standards: Building performance standards are energy or emissions targets that existing buildings must meet over time, reducing climate impacts. We are currently exploring a Building Performance Standards policy to transition buildings towards greater efficiency and clean electricity. 
  • Equitable Transportation Pricing: The City is exploring equitable transportation pricing, a charge for people who choose to drive through the downtown core during peak traffic, as one possible approach to support a more equitable transportation system, decrease traffic, and reduce climate pollution. While congestion pricing has proven to be an effective strategy for other cities, we will engage community in how best to root our policy development process in racial equity to ensure that road pricing does not exacerbate existing burdens BIPOC communities face when it comes to living in and traveling through the City of Seattle. 
  • Transportation Electrification: Decarbonization of transportation is critical to meet climate goals. Even with significant reductions in vehicle miles traveled, nearly all cars, buses and trucks will need to be electrified with City Light's carbon free electricity for Seattle to be carbon neutral by 2050. As such, the City is planning for a future where everything that moves people, goods, and services in and around the City is electrified. OSE, City Light and SDOT, in partnership with other city departments, have led a citywide effort to map out a draft blueprint for Seattle to pursue and accelerate actions, policies and technologies necessary to electrify transportation at scale. This strategy establishes aggressive goals for 2030 and lays out several actions related to infrastructure, policy, mobility and workforce development that will be taken over the next two years that will move us towards the 2030 goals.