Biomass-based negative emissions difficult to reconcile with planetary boundaries
Biomass-based negative emissions difficult to reconcile with planetary boundaries
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DOI：
10.1038/s41558-017-0064-y
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发表时间：
2018-02-01
影响因子：
30.7
通讯作者：
Popp, Alexander
中科院分区：
文献类型：
--
作者：
Heck, Vera;Gerten, Dieter;Popp, Alexander
根据《巴黎协定》，195个国家承诺将全球平均气温的升幅控制在远低于工业化前水平2摄氏度的水平，并努力将升幅控制在1.5摄氏度以内。(1)。据指出，这需要“在本世纪后半叶的温室气体人为排放和汇清除量之间取得平衡”(1)。这要么要求温室气体(GHG)零排放，要么要求正、负排放(NE)平衡(2，3)。与2摄氏度或1.5摄氏度目标相适应的路线图和社会经济情景依赖于通过具有碳捕获和封存的生物能源(BECCS)来平衡剩余的温室气体排放(4-7)。然而，大规模部署BECCS将意味着除了大气二氧化碳浓度(8，9)外，还将对地球系统的许多组成部分产生重大影响。在这里，我们探索了从专门的种植园通过BECCS进行NE的可行性，以及与行星边界(PBS)(10，11)对多种社会经济路径的潜在权衡。我们表明，虽然大规模的BECCS旨在降低PB在气候变化方面的压力，但它很可能会引导地球系统更接近PB的淡水利用，并导致PBS在陆地系统变化、生物圈完整性和生物地球化学流动方面的进一步越轨。
Under the Paris Agreement, 195 nations have committed to holding the increase in the global average temperature to well below 2 degrees C above pre-industrial levels and to strive to limit the increase to 1.5 degrees C (ref. (1)). It is noted that this requires "a balance between anthropogenic emissions by sources and removals by sinks of greenhouse gases in the second half of the century"(1). This either calls for zero greenhouse gas (GHG) emissions or a balance between positive and negative emissions (NE)(2,3). Roadmaps and socio-economic scenarios compatible with a 2 degrees C or 1.5 degrees C goal depend upon NE via bioenergy with carbon capture and storage (BECCS) to balance remaining GHG emissions(4-7). However, large-scale deployment of BECCS would imply significant impacts on many Earth system components besides atmospheric CO2 concentrations(8,9). Here we explore the feasibility of NE via BECCS from dedicated plantations and potential trade-offs with planetary boundaries (PBs)(10,11) for multiple socio-economic pathways. We show that while large-scale BECCS is intended to lower the pressure on the PB for climate change, it would most likely steer the Earth system closer to the PB for freshwater use and lead to further transgression of the PBs for land-system change, biosphere integrity and biogeochemical flows.