Systemic Risks of Excessive CCS Deployment in Power-Sector Decarbonization

Carbon capture and storage (CCS) is widely acknowledged as a key strategy for deep decarbonization of the power sector. However, the systemic risks associated with excessive CCS deployment remain underexplored, particularly in fossil-dependent economies like China. Using a scenario-driven integrated framework coupling the Global Change Assessment Model (GCAM) with an input-output model, we quantitatively evaluate the implications of excessive CCS adoption in China's power transition. Results indicate that excessive CCS deployment leads to a 14.63 petawatt-hour increase in thermal power generation by 2060, simultaneously causing a significant crowding-out of wind and solar capacity. This shift results in a 4,128 MtCO2 emission rebound by 2060, exceeding 10 Gt by 2100─around 3% of the remaining carbon budget for the 1.5 °C target. Concurrently, air pollutant emissions, including CO, NOx, and SO2 rise substantially, with CO annual emissions projected to double post-2050. Additionally, the pathway is projected to reduce employment by an additional 11 million and take up nearly a quarter of China's annual water use by 2060. Contrary to prevailing narratives emphasizing CCS cost-efficiency, this study highlights its structural trade-offs and underscores the need for system-wide optimization frameworks and adaptive governance mechanisms to ensure long-term sustainability.