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For centuries famine arose as a seemingly endless series of acute, regional and unanticipated events; it has transformed into a phenomenon, global in scale and continuous in nature. Half the world’s human population perpetually suffers some form of malnourishment, from either a scarcity of calories, protein or micronutrients or from a combination of these. Sheer population size has rendered the scale of suffering unprecedented. Perpetual famine has emerged during an era of abundant and relatively inexpensive soil, water and energy resources, improving crop yields, and a benign climate. However, the twentieth century trends of resource degradation, diminishing growth in crop yields and a warming atmosphere will likely continue, latently and perhaps synergistically impacting agricultural production, and therefore, threatening food security in the twenty-first century. Assuming some proportional relationship between food security and these resources, famine is here projected to greatly increase in the coming decades, severely impacting billions of people.  相似文献   
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Energy efficiency and conservation for individual Americans   总被引:1,自引:0,他引:1  
Americans make up only 4% of the world population, yet currently consume 25% of the world’s fossil fuels. The U.S. imports 63% of its oil and it is predicted that by 2020 the U.S. will be importing 95% of its oil resources. Over the past century, ample and affordable supplies of fossil fuels have powered the growth and prosperity of the economies of the US and other countries. Within this century, world oil supplies will decline while demand is projected to continue to increase, suggesting that we will have to transition to different fuels or become much more energy efficient or both. Looking ahead to the near decades, estimates are that consumers will have to reduce their energy use by at least 50%. This reduction will be necessary in large part due the decline in the availability of conventional oil and gas, but also because the U.S. population will continue to grow in number. Although government action is important, individuals too often discount their ability to make significant contributions to solving such major problems. This investigation identifies how informed and concerned individuals can collectively conserve fossil energy. Readers should send their comments on this paper to: BhaskarNath@aol.com within 3 months of publication of this issue. An erratum to this article can be found at  相似文献   
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This article reports a study of the economic viability of a separate household waste collection project, and considers its social and environmental benefits. The study was developed from the database obtained through the pilot project on separate collections in João Pessoa, the capital of Paraíba, in the northeast region of Brazil. The pilot project had been supported by the local municipal council since September 2000. The methodology applied to this study of economic viability is based on the economic quantification of the benefits and costs involved in the process of a separate collection of household waste. The benefits to the environment, owing to the reduction of the final disposal of household waste, were also evaluated. The results of this research are encouraging for the benefit cost relation (B/C) of both the quantified economic components and the environmental aspects. The values found for the relation B/C ranged from 1.27 to 1.77 depending on the economic quantification of the direct and indirect benefits to the components involved in the project, i.e., the waste collectors, the municipal council, the sellers of recycled material, and the recycling industry.  相似文献   
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Human Population Numbers as a Function of Food Supply   总被引:1,自引:1,他引:0  
Human population growth has typically been seen as the primary causative factor of other ecologically destructive phenomena. Current human disease epidemics are explored as a function of population size. That human population growth is itself a phenomenon with clearly identifiable ecological/biological causes has been overlooked. Here, human population growth is discussed as being subject to the same dynamic processes as the population growth of other species. Contrary to the widely held belief that food production must be increased to feed the growing population, experimental and correlational data indicate that human population growth varies as a function of food availability. By increasing food production for humans, at the expense of other species, the biologically determined effect has been, and continues to be, an increase in the human population. Understanding the relationship between food increases and population increases is proposed as a necessary first step in addressing this global problem. Resistance to this perspective is briefly discussed in terms of cultural bias in science.  相似文献   
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Soil Erosion: A Food and Environmental Threat   总被引:14,自引:0,他引:14  
Soil erosion is one of the most serious environmental and public health problems facing human society. Humans obtain more than 99.7% of their food (calories) from the land and less than 0.3% from the oceans and other aquatic ecosystems. Each year about 10 million ha of cropland are lost due to soil erosion, thus reducing the cropland available for food production. The loss of cropland is a serious problem because the World Health Organization reports that more than 3.7 billion people are malnourished in the world. Overall soil is being lost from land areas 10 to 40 times faster than the rate of soil renewal imperiling future human food security and environmental quality.  相似文献   
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