Geological Net Zero and the need for disaggregated accounting for carbon sinks

• 成果类型: Review
• 署名作者: Allen, Myles R.; Frame, David J.; Friedlingstein, Pierre; Gillett, Nathan P.; Grassi, Giacomo; Gregory, Jonathan M.; Hare, William; House, Jo; Huntingford, Chris; Jenkins, Stuart; Jones, Chris D.; Knutti, Reto; Lowe, Jason A.; Matthews, H. Damon; Meinshausen, Malte; Meinshausen, Nicolai; Peters, Glen P.; Plattner, Gian-Kasper; Raper, Sarah; Rogelj, Joeri; Stott, Peter A.; Solomon, Susan; Stocker, Thomas F.; Weaver, Andrew J.; Zickfeld, Kirsten
• 署名单位: University of Oxford; University of Oxford; University of Canterbury; University of Exeter; European Commission Joint Research Centre; EC JRC ISPRA Site; UK Research & Innovation (UKRI); Natural Environment Research Council (NERC); NERC National Centre for Atmospheric Science; University of Reading; Met Office - UK; University of Bristol; UK Centre for Ecology & Hydrology (UKCEH); Swiss Federal Institutes of Technology Domain; ETH Zurich; University of Leeds; Concordia University - Canada; University of Melbourne; Swiss Federal Institutes of Technology Domain; ETH Zurich; Swiss Federal Institutes of Technology Domain; Swiss Federal Institute for Forest, Snow & Landscape Research; Manchester Metropolitan University; Imperial College London; University of Exeter; Massachusetts Institute of Technology (MIT); University of Bern; University of Victoria; Simon Fraser University
• 刊物名称: Nature
• ISSN/ISSBN: 0028-3158
• DOI: 10.1038/s41586-024-08326-8
• 发表日期: 2025-02-13
• 关键词: cumulative carbon; path independence; atmospheric co2; land-use; climate; emissions; proportionality; uncertainty; targets; origin

摘要

Achieving net-zero global emissions of carbon dioxide (CO2), with declining emissions of other greenhouse gases, is widely expected to halt global warming. CO2 emissions will continue to drive warming until fully balanced by active anthropogenic CO2 removals. For practical reasons, however, many greenhouse gas accounting systems allow some 'passive' CO2 uptake, such as enhanced vegetation growth owing to CO2 fertilization, to be included as removals in the definition of net anthropogenic emissions. By including passive CO2 uptake, nominal net-zero emissions would not halt global warming, undermining the Paris Agreement. Here we discuss measures to address this problem, to ensure residual fossil fuel use does not cause further global warming: land management categories should be disaggregated in emissions reporting and targets to better separate the role of passive CO2 uptake; where possible, claimed removals should be additional to passive uptake; and targets should acknowledge the need for Geological Net Zero, meaning one tonne of CO2 permanently restored to the solid Earth for every tonne still generated from fossil sources. We also argue that scientific understanding of Net Zero provides a basis for allocating responsibility for the protection of passive carbon sinks during and after the transition to Geological Net Zero.