Land-based negative emissions: risks for climate mitigation and impacts on sustainable development

摘要: This paper focuses on the risks associated with “negative emissions” technologies (NETs) for drawing carbon dioxide from atmosphere through photosynthesis and storing it in land-based sinks or underground. Modelled mitigation pathways 1.5 °C assume NETs that range as high 1000 Gt CO2. We argue this is two to three times greater than amount of can be realistically assumed, given critical social objectives ecological constraints. Embarking a pathway assumes unrealistically large amounts future could lead society set near-term targets are too lenient thus greatly overshoot budget, without way undo damage. Pathways consistent rely smaller NETs, however, prove viable. presents framework assessing negative emissions context equity sustainable development. To do this, we identify types counting NETs: (1) will not ultimately feasible; (2) their large-scale deployment involves unacceptable impacts; (3) less effective hoped, due irreversible climate impacts, reversal stored carbon. highlight technical issues need resolved and—more importantly—the value judgements made, realistic potential environmental goals. Given normative at stake, these decisions should made within an open, transparent, democratic process. As input, offer here indicative assessment based precautionary effectiveness provisional extent which they conflict development goals related land, food climate.