Gund Institute for Environment, University of Vermont, Burlington, VT, United States; Vermont Experimental Program to Stimulate Competitive Research, University of Vermont, Burlington, VT, United States; Rubenstein School of Environment and Natural Resources, University of Vermont, Burlington, VT, United States.
Gund Institute for Environment, University of Vermont, Burlington, VT, United States; Vermont Experimental Program to Stimulate Competitive Research, University of Vermont, Burlington, VT, United States; Department of Community Development and Applied Economics, University of Vermont, Burlington, VT, United States.
J Environ Manage. 2021 Sep 1;293:112838. doi: 10.1016/j.jenvman.2021.112838. Epub 2021 Jun 1.
Excess phosphorus loading to waterbodies has led to increasing frequency and severity of harmful algal blooms, negatively impacting economic activity and human health. While interventions to improve water quality can create large societal benefits, these investments are costly and the value of benefits is often unknown. Understanding the social and economic impacts of reduced phosphorus loading is critical for developing effective land use policies and for generating public and political support for these initiatives. Here, we quantify the social benefits and costs of improving water quality in Lake Champlain under a range of phosphorus reduction and climate change scenarios between 2016 and 2050. We use statistical models to link water quality outputs from an established integrated assessment model with three categories of benefits: tourism expenditures, property sales, and avoided human health impacts. We estimate the costs of reducing phosphorus loading using data reported by the State of Vermont. We find that under the most aggressive phosphorus reduction scenario, the total benefits of improved water quality are $55 to $60 million between 2016 and 2050. Over this 35 year time horizon, the combined benefits do not outweigh the costs under any scenario. If the time horizon is extended to 2100 or beyond, however, the benefits may exceed the costs if the applied discount rate is less than 3%. Importantly, we almost certainly underestimate the value of clean water, due to the omission of other types of benefits. Despite this uncertainty, our study provides a tractable framework for disentangling the complex relationships between water quality and human well-being, and illuminates the value of reductions in phosphorus loading to society.
水体中过量的磷负荷导致有害藻类大量繁殖的频率和严重程度不断增加，对经济活动和人类健康产生负面影响。虽然改善水质的干预措施可以带来巨大的社会效益，但这些投资成本高昂，而且效益的价值往往未知。了解减少磷负荷的社会和经济影响对于制定有效的土地利用政策以及为这些举措争取公众和政治支持至关重要。在这里，我们在 2016 年至 2050 年期间，在一系列磷减排和气候变化情景下，量化了改善尚普兰湖水质的社会效益和成本。我们使用统计模型将一个成熟的综合评估模型的水质输出与三类效益联系起来：旅游支出、房地产销售和避免的人类健康影响。我们使用佛蒙特州报告的数据来估计减少磷负荷的成本。我们发现，在最激进的磷减排情景下，2016 年至 2050 年期间，水质改善的总效益为 5500 万至 6000 万美元。在这 35 年的时间内，在任何情景下，综合效益都不超过成本。然而，如果时间跨度延长到 2100 年或更远，那么如果应用的贴现率低于 3%，效益可能超过成本。重要的是，由于其他类型的效益被忽略，我们几乎可以肯定低估了清洁水的价值。尽管存在这种不确定性，但我们的研究为理清水质与人类福祉之间复杂的关系提供了一个可行的框架，并阐明了减少磷负荷对社会的价值。
