Greenhouse gas emissions inventories are the primary means of monitoring and reporting progress toward emission-reduction goals. In this inventory, Seattle’s emissions are considered from two perspectives:

  • “Core” emissions are those which the City has the greatest opportunity to influence and are the focus of Seattle’s 2013 Climate Action Plan: building energy use, road transportation, and waste management. The Plan recommends a package of actions to reduce GHG emissions in these core sectors by 58% by 2030 and 87% by 2050 from recent (2008) levels, not including offsets.
  • “Expanded” emissions include additional sources, such as industry, marine, rail, and air travel, yard equipment, and wastewater treatment. These sources serve regional or national demands and/or are more difficult for the City to influence, but they remain of interest to monitor trends and identify opportunities where City actions can have an impact.

In 2012, the analysis finds, road transportation (especially passenger travel) comprised the largest share of Seattle’s core emissions, 64%. Emissions associated with building energy comprised 33%, while emissions from waste comprised 3%. Accounting for offsets purchased by Seattle City Light for the small portion of fossil fuel-based electricity in its portfolio, total core emissions have declined 4%, from about 3.8 million tonnes CO2e in 1990 to about 3.6 million tonnes in 2008 and 2012. Over the same time period, Seattle’s population grew by 23% (118,000), and jobs increased by 14% (60,000). On a per-person basis, Seattle’s emissions have declined 22% since 1990 and 6% since 2008.

The expanded view is more consistent with the approach used in 2005, when Seattle adopted the suggested U.S. greenhouse gas emissions target from the Kyoto Protocol of 7% below 1990 emissions by 2012. By that measure, Seattle’s emissions totaled 6.0 million tonnes CO2e in 2012; GHGs were reduced by 1% from 1990 to 2012. Information from this inventory will help the City monitor its performance against its ambitious goals and will also inform ongoing climate action planning.

Download the report (PDF, 1MB)