Emergy Analysis of Human Carrying Capacity and Regional Sustainability: an Example Using the State of Maine
Emergy Analysis of Human Carrying Capacity and Regional Sustainability: an Example Using the State of Maine
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DOI：
10.1007/978-94-011-4976-1_41
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发表时间：
1998-06
影响因子：
3
通讯作者：
D. Campbell
中科院分区：
文献类型：
--
作者：
D. Campbell
一个区域在特定生活水平下的人口承载能力取决于该区域的经济和环境资源以及跨区域边界的资源交换。人口维持一定标准的时间长短取决于资源基础的使用率和更新率。所有的环境、经济和社会资源都是能源转换的结果；因此，它们的生产所需的能源可以通过将它们的能值转换为能值来具体说明和评估。能值被定义为一种可用能量，以前直接或间接地用来制造产品或服务。它的单位是埃焦耳。能值和指数被用来评估缅因州的资源基础，缅因州是一个政治界定的地区，并估计其在1980年生活水平下的人口承载能力和未来可能的资源基础。缅因州的能值指数与佛罗里达州、德克萨斯州和美国的类似指数进行了比较，以显示不同地区之间人类承载能力和可持续性的差异。1980年，缅因州、佛罗里达州、得克萨斯州和全国的生活水平以人均能量使用量衡量，落在相对较窄的3.4E16至4.3E16太阳埃焦耳y-1的范围内。一个区域的人口承载能力是在可持续发展的脉动范例和可再生资源基础提供的限制范围内考虑的。例如，在短期内，缅因州发展的人口承载能力在很大程度上取决于相对于可再生能源资源的燃料能值流入。如果购买的能值流入相对于缅因州的可再生能值增加到发达国家的平均比率，按照1980年的标准，缅因州的人口可能会增加到290万，即缅因州1980年人口的2.6倍。相比之下，仅以缅因州可再生资源为基础的人口承载能力，按1980年的生活标准计算为37万人，占1980年人口的33%。
The human carrying capacity for a region at a specified standard of living depends on the economic and environmental resources of the region and the exchange of resources across regional boundaries. The length of time that a human population living at a given standard can be sustained depends on the rates of use and renewal of the resource base. All environmental, economic, and social resources are produced as a result of energy transformations; therefore, the energy required for their production can be specified and evaluated in common terms by converting their energy values into emergy. Emergy is defined as the available energy of one kind, previously used up directly and indirectly to make a product or service. Its unit is the emjoule. Emergy values and indices are used to evaluate the resource base for Maine, a politically defined region, and to estimate its human carrying capacity at the 1980 standard of living and for possible future resource bases. Emergy indices for Maine are compared with similar indices for Florida, Texas, and the United States to demonstrate variations in human carrying capacity and sustainability among different regions. The 1980 standard of living for Maine, Florida, Texas, and the Nation as measured by emergy use per person fell within a relatively narrow range of 3.4E16 to 4.3E16 solar emjoules y-1. The human carrying capacity for a region is considered within a pulsing paradigm for sustainability and within the constraints provided by a renewable resource base. For example, in the short-term the developed human carrying capacity for Maine is largely determined by the fuel emergy inflow relative to renewable emergy resources. If purchased emergy inflows relative to Maine's renewable emergy increase to the average ratio for a developed country around 1980, the population living in Maine at 1980 standards could increase to 2.9 million or 2.6 times Maine's 1980 population. In contrast, the human carrying capacity based on Maine's renewable resources alone was 0.37 million people at the 1980 standard of living or 33% of the 1980 population.