Abstract
Building stock modeling can be used to identify trajectories that do not exceed the remaining carbon budget and support science-based pathways. A systematic approach is used from the field of prospective life-cycle assessment, which is based on systems thinking, to develop scenarios for the Austrian building stock that consider life-cycle greenhouse gas emissions. The influential parameters of the model are identified; their interactions are classified; quantitative future assumptions are adopted; and five scenario narratives are created. A maximum emission reduction of 90% from 2023 to 2050 is revealed. In comparison, leaving current policies in place would lead to a trajectory that reduces emissions by only 66%. Three additional scenarios achieve emission reductions between 84 and 86% by 2050, which may be compatible with the 2 °C carbon budget using an equal-per-capita approach. These scenarios represent different societal choices based on ambitious sufficiency (e.g., behavioral change), technological measures (e.g., a change in the industry), or both, with less effort from all actors. To ensure that Austria contributes to staying within the remaining carbon budget, policy makers are urged to systematically and quickly incorporate sufficiency into their policies and enable the necessary investments in carbon dioxide removal technologies.