This study evaluates long-term energy scenarios in California through 2050 using the California PATHWAYS model. PATHWAYS model is an economy wide, technology-specific scenario tool developed by Energy and Environmental Economics (E3). The PATHWAYS scenarios leverage prior research and analysis from other California state energy agencies and from E3, building upon and expanding E3’s prior work. These scenarios investigate options and costs to achieve a 40 percent reduction in greenhouse gas emissions by 2030 and an 80 percent reduction in greenhouse gas emissions by 2050, relative to 1990 levels. The results of this study advances the understanding of what is required for technology deployment and other GHG mitigation strategies if California is to meet its long-term climate goals. This report provides researchers and policy makers with information about key choices that could lower the costs of meeting the state’s GHG reduction goals.