Olivia Walker provides technical and advocacy expertise for local and state-level building energy efficiency and decarbonization policies and programs. In her prior role as a buildings and energy technical strategist for the American Cities Climate Challenge, Walker supported the Challenge's Western cities on their ambitious work to reduce carbon emissions from the built environment and facilitated network learning opportunities related to building decarbonization. Walker joined NRDC in 2016 as the program assistant for the City Energy Project—a collaboration between NRDC and the Institute for Market Transformation dedicated to reducing energy waste from buildings via local-level energy efficiency policies—and she subsequently became involved with the broader building decarbonization policy space from there. She holds a bachelor's degree in geology and geophysics with a focus in energy and environmental geoscience from Yale University. She is based in NRDC's Santa Monica office.