School of Natural Resources and the Environment, University of Arizona, Tucson, AZ 85721.
Institute on the Environment, University of Minnesota, St. Paul, MN 55108.
Proc Natl Acad Sci U S A. 2019 Feb 5;116(6):2130-2137. doi: 10.1073/pnas.1707812116. Epub 2019 Jan 22.
Voluntary sustainability standards (VSS) are stakeholder-derived principles with measurable and enforceable criteria to promote sustainable production outcomes. While institutional commitments to use VSS to meet sustainable procurement policies have grown rapidly over the past decade, we still have relatively little understanding of the () direct environmental benefits of large-scale VSS adoption; () potential perverse indirect impacts of adoption; and () implementation pathways. Here, we illustrate and address these knowledge gaps using an ecosystem service modeling and scenario analysis of Bonsucro, the leading VSS for sugarcane. We find that global compliance with the Bonsucro environmental standards would reduce current sugarcane production area (-24%), net tonnage (-11%), irrigation water use (-65%), nutrient loading (-34%), and greenhouse gas emissions from cultivation (-51%). Under a scenario of doubled global sugarcane production, Bonsucro adoption would further limit water use and greenhouse gas emissions by preventing sugarcane expansion into water-stressed and high-carbon stock ecosystems. This outcome was achieved via expansion largely on existing agricultural lands. However, displacement of other crops could drive detrimental impacts from indirect land use. We find that over half of the potential direct environmental benefits of Bonsucro standards under the doubling scenario could be achieved by targeting adoption in just 10% of global sugarcane production areas. However, designing policy that generates the most environmentally beneficial Bonsucro adoption pathway requires a better understanding of the economic and social costs of VSS adoption. Finally, we suggest research directions to advance sustainable consumption and production.
自愿可持续性标准(VSS)是由利益相关者制定的原则,具有可衡量和可执行的标准,以促进可持续生产成果。虽然过去十年间,机构承诺使用 VSS 来满足可持续采购政策的速度迅速增长,但我们对于大规模采用 VSS 的(1)直接环境效益、(2)潜在的不良间接影响以及(3)实施途径,仍知之甚少。在这里,我们使用甘蔗领域领先的 VSS(Bonsucro)的生态系统服务建模和情景分析,来阐明和解决这些知识空白。我们发现,全球范围内符合 Bonsucro 环境标准将减少当前的甘蔗种植面积(-24%)、净吨位(-11%)、灌溉用水量(-65%)、养分负荷(-34%)以及来自种植的温室气体排放(-51%)。在全球甘蔗产量翻番的情景下,Bonsucro 的采用将通过防止甘蔗在水资源紧张和高碳储量生态系统中扩张,进一步限制水的使用和温室气体排放。这一结果是通过在现有农业土地上的扩张实现的。然而,其他作物的替代可能会带来间接土地利用的不利影响。我们发现,在双倍情景下,Bonsucro 标准的潜在直接环境效益的一半以上可以通过仅在全球甘蔗生产区的 10%中实现采用来实现。然而,要设计出最有利于环境的 Bonsucro 采用途径的政策,需要更好地了解 VSS 采用的经济和社会成本。最后,我们建议研究方向以推进可持续消费和生产。