Transient reliance on carbon removal and storage in long-term energy system transitions

Most mitigation scenarios to achieve 1.5°C goal rely on carbon dioxide removal (CDR) and carbon capture and storage (CCS), raising concerns about their long-term sustainability within future energy systems. While several studies have explored pathways that reduce CDR and CCS by assuming additional transformative societal changes—such as lower energy demand, their cost and feasibility are difficult to evaluate, leading to uncertainty about their real-world plausibility. Here, we propose Transient reliance and Phase-out of CDR and CCS (TPCC) scenario; where CDR and CCS are used temporarily but gradually phased out thereafter resolving the long-term sustainability concerns. In the short-term, renewable energy deployment and electrification are maximized; in the mid-term, diversified CDR options enable temporary large-scale negative emissions without excessive land pressure; and in the long-term, synthetic fuels and hydrogen eliminate fossil-fuel residual emissions. While challenges remain, the TPCC presents critical implications for the design of future energy system transitions.