Low-Carbon Pathways

E3's Four Pillars of GHG Mitigation

The low-carbon pathways can be summarized into four broad actions that apply to all of the above sectors:

  • Efficiency & Conservation  
  • Fuel-Switching  
  • Decarbonizing Electricity & Electrification  
  • Decarbonizing Liquid & Gas Fuels

The graphic below shows the pathways applied to how the state of California would attain reductions by 2050:

California Pathways: GHG Scenarios Results written by A. Mahone, E. Hart, B. Haley, J. Williams, S. Borgenson, N. Ryan, S. Price, in April 2015.

Decarbonization Strategies

While it is a tall order to get on the road to deep decarbonization, the strategies required to overcome existing barriers are identified below:

  • Electric Grid: Transmission to carry renewable energy to the loads that need it, addressing the challenges of variability, must be built. Grid integration strategies to match loads to variable renewable energy must be developed. These will include grid connected-storage (batteries, pumped hydro, etc.); demand response; and real-time price signals tied to load fluctuations such as those that electric vehicle charging would add.  
  • Transport-Electric Grid Connection: Decarbonizing the electricity grid and the transportation sector go hand-in-hand. As explained above, cleaning the electric grid makes it possible to “fuel switch” to electric-powered transportation vehicles wherever technically possible, replacing dirty fossil fuel-based vehicles with vehicles powered by clean electricity. Renewable energy is variable and storage must compensate for the times when more or less energy than is consumed is produced. In addition to grid-connected storage, electric vehicle batteries or hydrogen for fuel cell vehicles can also provide storage. Transportation requires you to store energy anyway, which dovetails neatly with a future in which we will at times have a surplus of clean electrons from parked vehicles that are plugged-in to the grid.  
  • Building Energy Efficiency and Electric Vehicles Connection: Replacing electric resistance heat in an ordinary Seattle house with a middle-of-the-road heat pump, saves 60% (7,200 kW-hr) of the 12,000 kW-hr consumed for home heating in the winter. That energy is enough to drive a Nissan Leaf 24,000 miles.  
  • Biofuels: Biofuels will be required for marine, aviation, and potentially long-distance freight, at least for the foreseeable future but should not be used for cars.  
  • Policies: Policies that encourage renewable growth must be protected and expanded, including but not limited to: third-party ownership of rooftop solar; net-metering (which will evolve to time-of-use or value-of-solar pricing over time); Renewable Portfolio Standards; tax incentives; and utility business models that incentivize conservation and renewables.  
  • Capital: The renewable energy sector continues to boom with wind power purchase agreements and solar costs that are now competitive with fossil fuel prices. Accelerated investment in renewable energy and the energy delivery systems continues to be extremely important, especially in light of how subsidized the fossil fuel industry continues to be.

To gain a better understanding of what it takes to achieve deep decarbonization, please review the following references:


Deep Decarbonization Pathways Studies Analysis—Summary and analysis of decarbonization pathways studies to inform Northwest policymakers, funders, legislators, local government officials, and climate advocates about how to advance a low-carbon/decarbonization pathways study for the region, particularly for Washington and Oregon.

Northwest Deep Decarbonization Pathways StudyCase Statement for a deep decarbonization pathways study that would offer guidance to Washington and Oregon policymakers, advocates, and investors for developing climate policy by addressing the question: How does the Northwest decarbonize the built environment, transport sector, and electricity grid between now and 2050 and at what cost?


Low-Carbon Pathways Overview—Presentation that offers an overview of the low-carbon pathways to economy-wide deep decarbonization. (January 11, 2018)

Low-Carbon Pathways: Electricity—Presentation that explores the low-carbon pathways for the electricity sector. (January 23, 2018)

Low-Carbon Pathways: Transportation—Presentation that explores the low-carbon pathways for the transportation sector, with emphasis on electric vehicles and autonomous vehicles. (January 30, 2018)

Decarbonization in Action—Presentation that looks at decarbonization efforts in Germany, the European Union, China, and the United States. (February 8, 2018)

Low-Carbon Pathways for the Northwest—Presentation that explores the low-carbon pathways for the Northwest in the context of existing deep decarbonization pathways studies, both for the United States and for Washington and Oregon. (March 15, 2018)


Selected Decarbonization Reading ListReading list that Clean Energy Transition Institute Board member Ross Macfarlane and Executive Director Eileen V. Quigley developed for a course they co-taught during the Winter Quarter 2018 at Western Washington University’s Institute for Energy Studies. Readings and citations were current as of March 31, 2018.

Key Decarbonization References—A non-exhaustive, but curated, list of studies, reports, books, and articles that are valuable to read to gain an understanding of how deep decarbonization can be achieved current as of July 2017.

Transportation Decarbonization References—A list of studies, reports, books, and articles related to decarbonizing the freight, marine, aviation, and passenger vehicle sectors, current as of April 2017.

Eileen V. Quigley

Founder & Executive Director
Eileen V. Quigley is Founder and Executive Director of the Clean Energy Transition Institute. Eileen spent seven years at Climate Solutions identifying the transition pathways off oil and coal to a low-carbon future in Washington and Oregon. She built and led the New Energy Cities program, which partnered with 22 Northwest cities and counties to reduce carbon emissions. As Director of Strategic Innovations, she oversaw New Energy Cities, as well as Sustainable Advanced Fuels.
Full Bio & Other Posts

Get the latest updates from the Institute directly to your inbox.

Related Posts