Achieving global net-zero greenhouse gas emissions by 2050 is reshaping how the building sector measures and manages carbon impacts. As energy systems decarbonize and building operations become more efficient and electrified, embodied carbon—originating from material production, construction activities, and life-cycle processes—is emerging as a significant component of total emissions. To account for these evolving conditions, dynamic Life Cycle Assessment (LCA) provides a framework that integrates time-dependent emission factors, future energy mix projections, technological developments, and policy changes. Capturing these temporal variations in LCA provides a more realistic and comprehensive understanding of a building's life-cycle carbon performance across different decarbonization pathways. This approach supports more informed design, policy, and investment decisions to achieve long-term climate neutrality in the built environment. This study investigates the key uncertainties and the future role of dynamic LCA in a fully or nearly decarbonized world based on a case study in the USA, considering several decarbonization scenarios. The results indicate that concerted efforts are needed to decarbonize the economy to reduce the impacts of climate change. The scenarios also identify shifts in the hotspots of building environmental impact. Historically, the majority of emissions resulted from building operation, e.g., heating, cooling, and lighting. As decarbonized energy expands and system efficiency improves, operational carbon emissions decrease. What remains are the carbon emissions from materials, construction, maintenance, and end-of-life as well as a broader set of emissions affecting other impact categories. Dynamic LCA can model these time-dependent changes, helping researchers and practitioners understand how a building's carbon footprint really may unfold over its decades-long life cycle.