Integrating Consumption-Based Metrics into Sectoral Carbon Budgets to Enhance Sustainability Monitoring of Building Activities

Climate policies such as sectoral carbon budgets use national greenhouse gas emissions inventories to track the decarbonization of sectors. While they provide an important compass to guide climate action, the accounting framework in which they are embedded lacks flexibility for activities that are international and at the crossroads of different sectors. The building activities, being largely linked with important upstream emitters such as energy production or industrial activities, which can take place outside of national borders, are such an example. As legislation increasingly addresses the whole-life carbon emissions of buildings, it is vital to develop cross-sectoral accounting methods that effectively measure and monitor the overall impact of buildings. Such methods are essential for creating sound and holistic decarbonization pathways that align with sustainability policies. This article aims to provide a consistent approach for depicting the life-cycle emissions of buildings at the national level, using France as a case study. By integrating the different emission scopes with decarbonization pathways, this approach also enables the creation of comprehensive whole-life carbon budgets. The results show that the French building stock footprint reached 162 MtCO2eq in 2019, with 64% attributed to operational emissions, primarily from fossil fuel combustion, and the remainder to embodied emissions, mainly from upstream industrial and energy sectors. Overall, 20% of the emissions occurred outside the national borders. Under various global decarbonization pathways, the significance of embodied emissions is projected to increase, potentially comprising 78% of the life-cycle emissions by 2050 under the current policies. This underscores the necessity for climate policies to address emissions beyond territorial and operational boundaries.