The MCS stands on the shoulders of decades of work across government agencies. It is based on robust literature related to U.S. decarbonization from peer-reviewed journal articles and studies conducted by private, public, and non-profit organizations. The MCS was further informed by the input received at a series of stakeholder listening sessions with non-governmental and private sector organizations, and by ongoing collaboration with other nations that are developing mid-century strategies, including Canada and Mexico. Finally, the MCS is supported by original analysis and modeling that portrays pathways to a low-GHG economy by 2050. The MCS analysis combines economy-wide modeling that encapsulates all sources and sinks of GHG emissions with more granular sectorspecific models. We reference the results of this analysis throughout the remainder of this report, as we describe our vision for a mid-century low-GHG pathway. But uncertainty is no reason for inaction. Just as we take precautions to avoid major risks in our own lives, and just as we expect governments to take precautions to avoid major risks to their citizens, deep decarbonization will protect Americans against the extreme risks of climate change.