National Renewable Energy Laboratory, 15013 Denver W Pkwy, Golden, CO, 80401, USA.
Bren School of Environmental Science and Management, 2400 University of California, Santa Barbara, CA, 93117, USA.
Nat Commun. 2022 Jun 25;13(1):3635. doi: 10.1038/s41467-022-31146-1.
Direct air capture (DAC) is critical for achieving stringent climate targets, yet the environmental implications of its large-scale deployment have not been evaluated in this context. Performing a prospective life cycle assessment for two promising technologies in a series of climate change mitigation scenarios, we find that electricity sector decarbonization and DAC technology improvements are both indispensable to avoid environmental problem-shifting. Decarbonizing the electricity sector improves the sequestration efficiency, but also increases the terrestrial ecotoxicity and metal depletion levels per tonne of CO sequestered via DAC. These increases can be reduced by improvements in DAC material and energy use efficiencies. DAC exhibits regional environmental impact variations, highlighting the importance of smart siting related to energy system planning and integration. DAC deployment aids the achievement of long-term climate targets, its environmental and climate performance however depend on sectoral mitigation actions, and thus should not suggest a relaxation of sectoral decarbonization targets.
直接空气捕集（DAC）对于实现严格的气候目标至关重要，但尚未在这一背景下评估其大规模应用的环境影响。我们在一系列气候变化缓解情景中对两种有前途的技术进行了前瞻性生命周期评估，发现电力部门脱碳和 DAC 技术改进对于避免环境问题转移都是不可或缺的。电力部门脱碳提高了封存效率，但也增加了通过 DAC 每封存一吨 CO2 的陆地生态毒性和金属耗竭水平。通过提高 DAC 的材料和能源利用效率可以降低这些增加。DAC 表现出区域环境影响的变化，突出了与能源系统规划和整合相关的智能选址的重要性。DAC 的部署有助于实现长期气候目标，但它的环境和气候表现取决于部门减排行动，因此不应暗示部门脱碳目标的放宽。
