Future Life-Cycle Greenhouse Gas Emission Scenarios for the Austrian Building Stock: A Systematic Approach

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.

建筑存量建模可用于识别未超出剩余碳预算的排放轨迹，并支撑基于科学依据的减排路径。本研究采用基于系统思维的前瞻性生命周期评估（prospective life-cycle assessment）领域的系统方法，针对奥地利建筑存量开发兼顾全生命周期温室气体排放的各类情景。研究明确了模型的关键影响参数，对其交互作用进行分类，采纳量化的未来假设，并构建了五类情景叙事。研究显示，2023年至2050年间可实现最高90%的减排幅度；相较而言，若维持现有政策不变，排放仅能降低66%。另有三类情景可在2050年前实现84%至86%的减排，在人均均等分配法（equal-per-capita approach）的框架下，此类情景或可符合2℃碳预算要求。这些情景基于不同的社会选择：或是依托高标准的充足性转型（如行为模式转变）、或是采用技术手段（如产业变革），或是二者结合，且各参与方的投入相对更少。为确保奥地利能够为守住剩余碳预算作出贡献，研究敦促政策制定者系统性且快速地将充足性转型理念纳入政策体系，并为二氧化碳移除技术的必要投资提供支持。