Boyd Matt, Wilson Nick
Adapt Research Ltd, Reefton, New Zealand.
Department of Public Health, University of Otago, Wellington, New Zealand.
PLoS One. 2025 May 7;20(5):e0321203. doi: 10.1371/journal.pone.0321203. eCollection 2025.
Abrupt global catastrophic risks (GCRs) are not improbable and could massively disrupt global trade leading to shortages of critical commodities, such as liquid fuels, upon which industrial food production, processing and distribution depends. Previous studies have suggested urban agriculture as a resilience measure in the context of climate change and other natural hazards.
To estimate the contribution a radical pivot to urban agriculture could have in building resilience to GCRs and the near-urban industrial agriculture needed to supplement urban food production.
We determined optimum crops through mathematical optimization for food calorie and protein supply per land area for both urban and near-urban (industrial) agriculture. We calculated the land area available for food production within a temperate globally median-sized city using Google Earth image analysis of residential lots and open city spaces. We calculated the population that could be fed through urban agriculture alone, and the extra near-urban land required for cropping with industrial agriculture to feed the remaining city population, under both normal climate, and potential nuclear winter conditions.
The optimal crops for urban agriculture were peas (normal climate), and sugar beet/spinach (nuclear winter); while those optimal for industrial near-urban production were potatoes (normal climate), and wheat/carrots (nuclear winter). Urban agriculture could feed a fifth (20%) of the population. At least 1140 hectares of near-urban cultivation could make up the shortfall. Another 110 hectares of biofuel feedstock like canola (rapeseed) could provide biodiesel to run agricultural machinery without fuel trade. Significantly more cultivated area is needed in nuclear winter scenarios due to reduced yields.
Relatively little optimized near-urban industrial agriculture, along with intensified urban agriculture could feed a median-sized city in a GCR, while minimizing fuel requirements. Governments and municipal authorities could consider land use policy that encourages development of urban agriculture and near-urban cultivation of optimal crops, along with processing and local biofuel refining capacity.
突发的全球灾难性风险（GCRs）并非不太可能发生，且可能极大地扰乱全球贸易，导致关键商品短缺，如液体燃料，而工业化食品生产、加工和分销依赖于此。先前的研究已提出城市农业作为应对气候变化和其他自然灾害的恢复力措施。
评估向城市农业的彻底转变在增强对全球灾难性风险的恢复力方面的贡献，以及补充城市粮食生产所需的近城市工业化农业。
我们通过数学优化确定了城市和近城市（工业化）农业每单位土地面积提供食物热量和蛋白质的最佳作物。我们利用谷歌地球对住宅用地和城市开放空间的图像分析，计算了一个温带全球中等规模城市内可用于粮食生产的土地面积。我们计算了仅通过城市农业能够养活的人口数量，以及在正常气候和潜在核冬天条件下，为养活其余城市人口而进行工业化农业种植所需的额外近城市土地面积。
城市农业的最佳作物在正常气候下是豌豆，在核冬天条件下是甜菜/菠菜；而近城市工业化生产的最佳作物在正常气候下是土豆，在核冬天条件下是小麦/胡萝卜。城市农业能够养活五分之一（20%）的人口。至少1140公顷的近城市耕地可弥补缺口。另外110公顷的生物燃料原料，如油菜（油菜籽），可在没有燃料贸易的情况下提供生物柴油来运行农业机械。由于产量降低，在核冬天情况下需要显著更多的耕地面积。
相对较少的优化后的近城市工业化农业，连同强化的城市农业，能够在全球灾难性风险下养活一个中等规模的城市，同时将燃料需求降至最低。政府和市政当局可考虑土地使用政策，鼓励城市农业发展以及对最佳作物进行近城市种植，同时具备加工和当地生物燃料提炼能力。
