Sovacool Benjamin K, Baum Chad M, Low Sean
Aarhus University, Aarhus, Denmark.
Science Policy Research Unit (SPRU), University of Sussex, Jubilee Building, Room 367, Falmer, BN1 9SL East Sussex UK.
Mitig Adapt Strateg Glob Chang. 2022;27(8):58. doi: 10.1007/s11027-022-10030-9. Epub 2022 Oct 3.
Negative emissions technologies and solar radiation management techniques could contribute towards climate stability, either by removing carbon dioxide from the atmosphere and storing it permanently or reflecting sunlight away from the atmosphere. Despite concerns about them, such options are increasingly being discussed as crucial complements to traditional climate change mitigation and adaptation. Expectations around negative emissions and solar radiation management and their associated risks and costs shape public and private discussions of how society deals with the climate crisis. In this study, we rely on a large expert survey ( = 74) to critically examine the future potential of both negative emission options (e.g., carbon dioxide removal) and solar radiation management techniques. We designed a survey process that asked a pool of prominent experts questions about (i) the necessity of adopting negative emissions or solar radiation management options, (ii) the desirability of such options when ranked against each other, (iii) estimations of future efficacy in terms of temperature reductions achieved or gigatons of carbon removed, (iv) expectations about future scaling, commercialization, and deployment targets, and (v) potential risks and barriers. Unlike other elicitation processes where experts are more positive or have high expectations about novel options, our results are more critical and cautionary. We find that some options (notably afforestation and reforestation, ecosystem restoration, and soil carbon sequestration) are envisioned frequently as necessary, desirable, feasible, and affordable, with minimal risks and barriers (compared to other options). This contrasts with other options envisaged as unnecessary risky or costly, notably ocean alkalization or fertilization, space-based reflectors, high-altitude sunshades, and albedo management via clouds. Moreover, only the options of afforestation and reforestation and soil carbon sequestration are expected to be widely deployed before 2035, which raise very real concerns about climate and energy policy in the near- to mid-term.
负排放技术和太阳辐射管理技术有助于实现气候稳定，其方式要么是从大气中去除二氧化碳并永久储存，要么是将阳光反射出大气层。尽管存在担忧，但这些选项正日益被视为传统气候变化缓解和适应措施的关键补充。围绕负排放和太阳辐射管理及其相关风险和成本的预期，影响着社会应对气候危机的公共和私人讨论。在本研究中，我们依靠一项大规模专家调查（n = 74），对负排放选项（如二氧化碳去除）和太阳辐射管理技术的未来潜力进行批判性审视。我们设计了一个调查过程，向一批杰出专家询问以下问题：（i）采用负排放或太阳辐射管理选项的必要性；（ii）相互比较时这些选项的可取性；（iii）对实现温度降低或去除的碳千兆吨数方面未来功效的估计；（iv）对未来规模扩大、商业化和部署目标的预期；以及（v）潜在风险和障碍。与其他专家对新选项更为积极或抱有高期望的征求意见过程不同，我们的结果更为批判性和警示性。我们发现，一些选项（特别是造林和再造林、生态系统恢复以及土壤碳固存）经常被视为必要、可取、可行且经济实惠，风险和障碍最小（与其他选项相比）。这与其他被认为不必要、有风险或成本高昂的选项形成对比，特别是海洋碱化或施肥、天基反射器、高空遮阳罩以及通过云层进行反照率管理。此外，预计只有造林和再造林以及土壤碳固存选项会在2035年前广泛部署，这在近期至中期引发了对气候和能源政策的切实担忧。
