Getting to zero: a pathway to a carbon neutral Seattle

Recognizing the extraordinary challenge of carbon neutrality and in preparation for updating its Climate Action Plan by 2012, the Seattle Office of Sustainability and Environment (OSE) commissioned SEI and its partners at Cascadia Consulting Group and ICF International to develop a scenario of how the city might be able to achieve carbon neutrality.

The SEI team and OSE, with guidance from our Technical Review Committee, constructed a Carbon Neutral scenario from the “bottom up,” by developing a suite of ambitious strategies based on aggressive deployment at plausible penetration rates of technologies and practices. The resulting scenario is one of many possible pathways to carbon neutrality and serves to illuminate the depth of potential emissions reductions that could move Seattle toward becoming a carbon-neutral city.

The scenario results suggest that implementation of a full suite of emissions-reducing strategies could cut Seattle’s per capita GHG emissions by 30% by 2020, 60% by 2030, and 90% by 2050, relative to 2008 levels. These reductions would require:

• Shifts to less GHG-intensive travel modes such as ride sharing, transit, walking and biking lead to 30% less per-capita travel by light duty vehicles in 2030 and 50% less by 2050, relative to 2008 levels.
• Dramatic increases in energy efficiency in building design and operations, as well as in vehicle efficiency, result in over 30% energy savings by 2030 (per capita in residential, per square foot in commercial, and per-mile in vehicles) and over 50% by 2050, relative to 2008 levels.
• Transitioning homes, businesses, and vehicles to lower-carbon energy sources: electricity (or possibly hydrogen) in the long run, biofuels as a bridging strategy for transportation until electric vehicles predominate, and to a much lesser extent, sustainable biomass sources (for district energy systems).

Many of these strategies can provide benefits well beyond emissions reductions and are well within the City’s sphere of influence. However, federal and international action will be essential for the City’s goals to be achievable. Even with concerted action at all levels, eliminating every ton of GHG emissions may prove too difficult or costly, especially in the next few decades. Consequently, meeting the City’s goal may require offsetting remaining emissions through increased sequestration activities, credit for selling excess renewable energy, or other measures. The City can also use these options to achieve more ambitious goals.

Download the report (external link, PDF, 2.7MB)

Download the technical appendix, Review of Approach and Assumptions (external link, PDF, 1.3MB)