Isotope Biogeochemistry and Gas Fluxes, Leibniz Centre for Agricultural Landscape Research, Müncheberg 15374, Germany.
UK Centre for Ecology & Hydrology, Environment Centre Wales, Bangor LL57 2UW, United Kingdom.
Proc Natl Acad Sci U S A. 2023 Aug 8;120(32):e2207081120. doi: 10.1073/pnas.2207081120. Epub 2023 Jul 31.
We assess wheat yield losses occurring due to ozone pollution in India and its economic burden on producers, consumers, and the government. Applying an ozone flux-based risk assessment, we show that ambient ozone levels caused a mean 14.18% reduction in wheat yields during 2008 to 2012. Furthermore, irrigated wheat was particularly sensitive to ozone-induced yield losses, indicating that ozone pollution could undermine climate-change adaptation efforts through irrigation expansion. Applying an economic model, we examine the effects of a counterfactual, "pollution-free" scenario on yield losses, wheat prices, consumer and producer welfare, and government costs. We explore three policy scenarios in which the government support farmers at observed levels of either procurement prices (fixed-price), procurement quantities (fixed-procurement), or procurement expenditure (fixed-expenditure). In pollution-free conditions, the fixed-price scenario absorbs the fall in prices, thus increasing producer welfare by USD 2.7 billion, but total welfare decreases by USD 0.24 billion as government costs increase (USD 2.9 billion). In the fixed-procurement and fixed-expenditure scenarios, ozone mitigation allows wheat prices to fall by 38.19 to 42.96%. The producers lose by USD 5.10 to 6.01 billion, but the gains to consumers and governments (USD 8.7 to 10.2 billion) outweigh these losses. These findings show that the government and consumers primarily bear the costs of ozone pollution. For pollution mitigation to optimally benefit wheat production and maximize social welfare, new approaches to support producers other than fixed-price grain procurement may be required. We also emphasize the need to consider air pollution in programs to improve agricultural resilience to climate change.
我们评估了印度臭氧污染导致的小麦减产及其对生产者、消费者和政府造成的经济负担。通过应用基于臭氧通量的风险评估,我们发现 2008 年至 2012 年期间,环境臭氧水平导致小麦平均减产 14.18%。此外,灌溉小麦对臭氧引起的减产特别敏感,表明臭氧污染可能会通过灌溉扩张破坏气候变化适应努力。通过应用经济模型,我们研究了在“无污染”假设情景下对减产、小麦价格、消费者和生产者福利以及政府成本的影响。我们探讨了三种政策情景,政府在采购价格(固定价格)、采购数量(固定采购)或采购支出(固定支出)方面以观察到的水平支持农民。在无污染条件下,固定价格情景吸收了价格下跌的影响,从而使生产者福利增加 27 亿美元,但由于政府成本增加(29 亿美元),总福利减少 2.4 亿美元。在固定采购和固定支出情景下,臭氧缓解使小麦价格下跌 38.19%至 42.96%。生产者损失 51 亿至 601 亿美元,但消费者和政府的收益(87 亿至 102 亿美元)超过了这些损失。这些发现表明,政府和消费者主要承担臭氧污染的成本。为了使污染缓解措施能够优化小麦生产并使社会福利最大化,可能需要采用除固定价格粮食采购以外的支持生产者的新方法。我们还强调需要在提高农业对气候变化适应能力的计划中考虑空气污染。