Co-producing climate policy and negative emissions: trade-offs for sustainable land-use
Co-producing climate policy and negative emissions: trade-offs for sustainable land-use
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DOI：
10.1017/sus.2018.6
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发表时间：
2018-06
影响因子：
5.5
通讯作者：
Kate Dooley;Peter K. Christoff;K. Nicholas
中科院分区：
文献类型：
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作者：
Kate Dooley;Peter K. Christoff;K. Nicholas
根据《巴黎协定》，各国承诺防止危险的全球变暖。在本世纪后半叶实现净零排放的设想取决于土地（森林和生物能源）从大气中去除碳。模拟的陆地缓解水平可能会减少生产性农业用地的可用性，并侵蚀自然土地，可能会产生重大的社会和环境后果。然而，在对模型产出的政策采纳中，这些问题没有得到充分认识。了解科学和政策如何相互作用以产生对减缓途径的期望，使我们能够考虑依赖土地进行减缓所固有的权衡。科学使人们能够更好地理解气候变化的原因和影响，但也可以用技术术语定义“气候问题”，并提供技术解决方案，如最近将负排放技术（NET）纳入综合评估模型（IAM）以实现巴黎协定的温度目标。本文探讨了陆地碳去除的可持续性，使用联合生产的透镜来解释NET作为关键减缓选择的合法性。我们评估了最新一代<2 °C情景中的NET规模，发现预计的陆基减缓水平意味着与其他社会目标的强烈权衡。未来对专用农田生物能源的需求推动了所有模式的大规模土地利用变化。模型产出的上限将要求全球耕地增加一倍，到2100年可能损失目前牧场和自然土地的四分之一。我们发现，基于模型的知识作为“客观科学”的看法，否则可能会更严格的辩论和争议的结果提供权威。建模人员和政策专家在制定缓解情景方面的更密切接触，将使知识生产的谈判形式更多，从而更好地澄清和代表利用有限土地资源所涉及的多重目标和利益。
Non-technical summary Under the Paris Agreement, nations have committed to preventing dangerous global warming. Scenarios for achieving net-zero emissions in the second half of this century depend on land (forests and bioenergy) to remove carbon from the atmosphere. Modelled levels of land-based mitigation could reduce the availability of productive agricultural land, and encroach on natural land, with potentially significant social and environmental consequences. However, these issues are poorly recognized in the policy-uptake of modelled outputs. Understanding how science and policy interact to produce expectations about mitigation pathways allows us to consider the trade-offs inherent in relying on land for mitigation. Technical summary Science enables better understanding of climate change causes and impacts but may also define the ‘climate problem’ in technical terms, with technical solutions, as seen in the recent inclusion of negative emissions technologies (NETs) in Integrated Assessment Models (IAMs) to meet the Paris Agreement's temperature goals. This paper examines the sustainability of land-based carbon removal, using a co-production lens to explain the legitimization of NETs as key mitigation options. We evaluate the scale of NETs in the most recent generation of <2 °C scenarios, finding that projected levels of land-based mitigation imply strong trade-offs with other societal goals. Future demand for bioenergy from dedicated cropland drives large-scale land-use change across all models. Upper ranges of modelled outputs would require up to a doubling of global cropland, with potential losses of up to a quarter of both current pasture and natural lands by 2100. We find that the perception of model-based knowledge as ‘objective science’ lends authority to outcomes that might otherwise be more critically debated and contested. Closer engagement between modellers and policy experts for mitigation scenario development would allow for more negotiated forms of knowledge production that might better clarify and represent the multiple objectives and interests at stake in the utilization of limited land resources.