Merfort Anne, Strefler Jessica, Abrahão Gabriel, Bauer Nico, Dorndorf Tabea, Kriegler Elmar, Luderer Gunnar, Merfort Leon, Edenhofer Ottmar
Potsdam Institute for Climate Impact Research (PIK), Member of the Leibniz Association, Potsdam, Germany.
Global Energy Systems Analysis, Technische Universität Berlin, Berlin, Germany.
Nat Commun. 2025 Jun 12;16(1):5298. doi: 10.1038/s41467-025-60606-7.
Net-zero commitments have become the focal point for countries to communicate long-term climate targets. However, to this point it is not clear to what extent conventional emissions reductions and carbon dioxide removal (CDR) will contribute to net-zero. An integrated market for emissions and removals with a uniform carbon price delivers the economically efficient contribution of CDR to net-zero. Yet it might not fully internalise sustainability risks of CDR and hence could lead to its overuse. In this study, we explore the implications of separating targets for emissions and for removals delivered by novel CDR in global net-zero emissions pathways with the Integrated Assessment Model REMIND. We find that overall efficiency losses induced by such separation are moderate. Furthermore, limiting the CDR target comes with increasing emission prices but also significant benefits: lower cumulative emissions, a lower financial burden for public finance of CDR and limited reliance on geologic CO storage but fails to lower the biomass demand. Proposed targets should also ensure sufficient CDR deployment to achieve net-negative emissions in the second half of the 21st century.
净零排放承诺已成为各国传达长期气候目标的焦点。然而，到目前为止，传统的减排措施和二氧化碳去除（CDR）在多大程度上有助于实现净零排放尚不清楚。一个具有统一碳价的排放和去除综合市场能实现CDR对净零排放的经济高效贡献。然而，它可能无法完全将CDR的可持续性风险内部化，因此可能导致其过度使用。在本研究中，我们使用综合评估模型REMIND探讨了在全球净零排放路径中，将新型CDR的排放目标和去除目标分开的影响。我们发现，这种分离导致的总体效率损失是适度的。此外，限制CDR目标会带来排放价格上涨，但也有显著好处：更低的累计排放量、CDR公共财政的更低财务负担以及对地质碳储存的有限依赖，但无法降低生物质需求。提议的目标还应确保充分部署CDR，以在21世纪下半叶实现净负排放。
