Abstract：
Carbon dioxide removal (CDR) is necessary for reaching net zero emissions, with studies showing potential deployment at multi-GtCO2 scale by 2050. However, excessive reliance on future CDR entails serious risks, including delayed emissions cuts, lock-in of fossil infrastructure, and threats to sustainability from increased resource competition. This study highlights an alternative pathway─prioritizing near-term non-CDR mitigation and minimizing CDR dependence. We impose a 1 GtCO2 limit on global novel CDR deployment by 2050, forcing aggressive early emissions reductions compared to 8-22 GtCO2 in higher CDR scenarios. Our results reveal that this low CDR pathway significantly decreases fossil fuel use, greenhouse gas (GHG) emissions, and air pollutants compared to higher CDR pathways. Driving rapid energy transitions eases pressures on land (including food cropland), water, and fertilizer resources required for energy and negative emissions. However, these sustainability gains come with higher mitigation costs from greater near-term low/zero-carbon technology deployment for decarbonization. Overall, this work provides strong evidence for maximizing non-CDR strategies such as renewables, electrification, carbon neutral/negative fuels, and efficiency now rather than betting on uncertain future CDR scaling. Ambitious near-term mitigation in this decade is essential to prevent lock-in and offer the best chance of successful deep decarbonization. Our constrained CDR scenario offers a robust pathway to achieving net zero emissions with limited sustainability impacts.
摘要：
二氧化碳去除（CDR）对于实现净零排放是必要的，研究表明，到2050年，潜在的部署将达到多吨二氧化碳的规模。然而,过度依赖未来的CDR会带来严重的风险，包括延迟减排，锁定化石基础设施，以及资源竞争加剧对可持续性的威胁。这项研究强调了一种替代途径-优先考虑近期非CDR缓解并最大程度地减少CDR依赖。到2050年，我们对全球新型CDR部署实施了1GtCO2的限制，迫使在较高CDR方案中大幅减少8-22GtCO2的排放。我们的结果表明，这种低CDR途径显着减少了化石燃料的使用，温室气体（GHG）排放，和空气污染物相比，较高的CDR途径。推动快速的能源转型缓解了土地（包括粮食田）的压力，水,能源和负排放所需的化肥资源。然而,这些可持续性收益伴随着更高的缓解成本，这些成本来自于更多的短期低碳/零碳技术部署脱碳。总的来说,这项工作为最大化可再生能源等非CDR战略提供了强有力的证据，电气化,碳中性/负燃料，现在和效率，而不是押注不确定的未来CDR扩展。在这十年中，雄心勃勃的近期缓解措施对于防止锁定并提供成功深度脱碳的最佳机会至关重要。我们受限的CDR方案为实现净零排放提供了一条稳健的途径，同时对可持续性影响有限。
