CO2 sequestration technologies (CSTs) allow for increased CO2 emissions without exceeding a chosen temperature limit by creating additional carbon budgets. While these CO2 sequestration technologies offer low-cost routes to net-zero emissions, namely, the CST benefits, they impede progress to the Sustainable Development Goals, namely, the CST disbenefits. Focusing on China, we assess both the CST disbenefits and benefits in the climate-energy-air-health cascade by an integrated modeling framework. We show that, CST can save 4.98-15.65 trillion CNY in achieving net-zero emissions while compromising the sustainability on non-fossil energy penetration, air quality, and public health improvement, leading to a substantial loss up to 7.82 trillion CNY during 2020-2060. Given the high likelihood of a large-scale deployment of CSTs in the future, pursuing policy coherence that balances trade-offs between CST disbenefits and benefits is vital. To that end, CSTs should be allocated to power sectors as a priority and stringent end-of-pipe equipment should be retrofitted into non-power sectors before CST allocation.
Keywords: Negative emission technology; Net-zero emissions; Policy coherence; Remaining carbon budget; Sustainable Development Goals.