While progress has been made in the development of decarbonization technologies, much work remains in scale-up and deployment. For decarbonization technologies to reach meaningful scale, real-world constraints, societal, economic, and political, must be considered. To identify the primary challenges and opportunities to deploying decarbonization technologies at scale across major sectors of the U.S. economy, the Board on Energy and Environmental Systems of the National Academies of Sciences, Engineering, and Medicine convened a workshop on July 22-23, 2019. In addition to technology-specific and sector-specific studies, the workshop considered the types of societal transformations required, as well as potential policy drivers for carbon dioxide emissions reductions. This publication summarizes the presentations and discussion of the workshop.