Will the circle be unbroken? The climate mitigation and sustainable development given by a circular economy of carbon, nitrogen, phosphorus and water
Will the circle be unbroken? The climate mitigation and sustainable development given by a circular economy of carbon, nitrogen, phosphorus and water
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圆圈会不会被打破？
DOI：
10.1039/d2su00121g
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发表时间：
2023
期刊：
影响因子：
--
通讯作者：
McKenna P
中科院分区：
文献类型：
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作者：
McKenna P
闭合农业、人类饮食和卫生服务之间的碳、营养物质和水流动的循环，在公共卫生、粮食安全和气候缓解的多个平台上为人类带来好处。本研究通过描述全球“功能齐全”的循环经济的假设情景来评估这些效益，其中100%的C，N和P从人类排泄物中回收并返回农业土壤。计算作物养分需求量，并与可回收量进行比较，并介绍化肥生产、化肥施用和卫生服务产生的温室气体排放量，以及淡水供应和作物灌溉需求。这些被认为是分析这种循环经济的更广泛的影响，这种经济是由饮食营养需求驱动的，对气候变化，提供卫生服务和作物灌溉，在2022年，并预测到2030年和2050年。我们发现，循环经济输送作物养分和减少温室气体排放的能力因地区而异。一些地区受益于用排泄物衍生的肥料补充传统矿物肥料，另一些地区则通过提高资源回收率减少环境卫生服务的温室气体排放。一个假设的，功能齐全的循环经济，回收所有排泄物营养C，到2022年，氮和磷将使氮和磷矿物肥料生产和应用的全球温室气体排放量每年减少140 Tg CO2当量（CO2 e）（占矿物肥料生产和施用总排放量的12%），每年最多可为全球农田提供104 Tg C的固碳量（约占土壤固碳潜力的12%）。然而，一部分被隔离的碳将通过土壤呼吸返回大气，对其他土壤功能如作物养分肥力也有好处。通过这些措施，卫生服务温室气体排放量的最大潜在减少量将在2022年每年减少445兆吨二氧化碳当量，到2050年将增加到562兆吨二氧化碳当量。我们的研究结果提供了证据，以指导具体的区域政策，减少温室气体排放，抵消矿物肥料的使用和优化城市用水利用循环经济。
Closing the loop in the flow of C, nutrients and water between agriculture, the human diet and sanitation services offers benefits for humanity across multiple platforms of public health, food security and climate mitigation. This study assesses these benefits by describing the hypothetical scenario of a global, ‘fully functional’ circular economy, in which 100% of C, N and P were recovered from human excreta and returned to agricultural soil. Crop nutrient demand is calculated and compared with that which could be recovered, and greenhouse (GHG) emissions from fertilizer production, fertilizer application and sanitation services are presented, as are freshwater availability and crop irrigation requirements. These are considered to analyse the broader effects of this circular economy that is driven by dietary nutrition demand on climate change, the provision of sanitation services and crop irrigation, in 2022 and with projections to 2030 and 2050. We find the capacity of the circular economy to deliver crop nutrients and mitigate GHG emissions varies by region. Some regions benefit from supplementing conventional mineral fertilizers with excreta-derived fertilizers, others from reducing GHG emissions from sanitation services through improved resource recovery rates. A hypothetical, fully functional circular economy that recovers all excreta nutrient C, N and P would reduce global GHG emissions from N and P mineral fertilizer production and application by 140 Tg CO2 equivalents (CO2 e) per year in 2022 (∼12% of total emissions from mineral fertilizer production and application) and provide a maximum of 104 Tg C per year for sequestration in global cropland (∼12% of estimated annual soil C sequestration potential). A portion of this sequestered C will return to the atmosphere via soil respiration, however, with co-benefits to other soil functions such as crop nutrient fertility. The maximum potential reduction in GHG emissions from sanitation services through these measures would bring reductions of 445 Tg CO2 e per year in 2022, rising to 562 Tg CO2 e in 2050. Our results provide evidence to guide specific regional policy on reducing GHG emissions, offsetting mineral fertilizer use and optimizing municipal water use using the circular economy.