{"title":"第29天:使人类的需求和数量适应地球的资源。","authors":"L. Brown","doi":"10.2307/1965643","DOIUrl":null,"url":null,"abstract":"In France a riddle is used to instruct schoolchildren in the nature of exponential growth. The riddle starts with a single leaf in the lily pond with the number of leaves doubling each day. The teacher asks when is the pond 1/2 full if it is full on the 30th day and the answer is \"on the 29th day.\" The world now with a population of 4 billion may already be at least 1/2 full. If doubling of population occurs within the next generation the \"pond\" could be entirely full. A doubling of population would mean that a great majority of countries will be confronted with ecological economic and political stresses that may be unmanageable. Signs of stress on the worlds principal biological systems and energy resources indicate that in many places they have already reached their limit and simply cannot withstand a tripling or quadrupling of population pressures. Population growth multiplies the number of people who are in need of social essentials at the same time it reduces the resources able to satisfy them. Attention here is focused on understanding the threat of population growth the dimensions of ecological stresses and the consequences the impact of population growth on food needs and economic stresses. The question remains as to how humankind will accommodate to the earths natural systems and resources. Although analysts can define the elements of accommodation and prepare the timetables for making the required changes only governments have sufficient power to implement them by means of legislation budgetary and fiscal policies taxation and the analytical and educational capacities of government institutions.","PeriodicalId":76336,"journal":{"name":"Population reports. Series E, Law and policy","volume":"5 1","pages":"54-72"},"PeriodicalIF":0.0000,"publicationDate":"1978-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.2307/1965643","citationCount":"2","resultStr":"{\"title\":\"The twenty-ninth day: accommodating human needs and numbers to the earth's resources.\",\"authors\":\"L. Brown\",\"doi\":\"10.2307/1965643\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"In France a riddle is used to instruct schoolchildren in the nature of exponential growth. The riddle starts with a single leaf in the lily pond with the number of leaves doubling each day. The teacher asks when is the pond 1/2 full if it is full on the 30th day and the answer is \\\"on the 29th day.\\\" The world now with a population of 4 billion may already be at least 1/2 full. If doubling of population occurs within the next generation the \\\"pond\\\" could be entirely full. A doubling of population would mean that a great majority of countries will be confronted with ecological economic and political stresses that may be unmanageable. Signs of stress on the worlds principal biological systems and energy resources indicate that in many places they have already reached their limit and simply cannot withstand a tripling or quadrupling of population pressures. Population growth multiplies the number of people who are in need of social essentials at the same time it reduces the resources able to satisfy them. Attention here is focused on understanding the threat of population growth the dimensions of ecological stresses and the consequences the impact of population growth on food needs and economic stresses. The question remains as to how humankind will accommodate to the earths natural systems and resources. Although analysts can define the elements of accommodation and prepare the timetables for making the required changes only governments have sufficient power to implement them by means of legislation budgetary and fiscal policies taxation and the analytical and educational capacities of government institutions.\",\"PeriodicalId\":76336,\"journal\":{\"name\":\"Population reports. Series E, Law and policy\",\"volume\":\"5 1\",\"pages\":\"54-72\"},\"PeriodicalIF\":0.0000,\"publicationDate\":\"1978-03-01\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"https://sci-hub-pdf.com/10.2307/1965643\",\"citationCount\":\"2\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Population reports. 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The twenty-ninth day: accommodating human needs and numbers to the earth's resources.
In France a riddle is used to instruct schoolchildren in the nature of exponential growth. The riddle starts with a single leaf in the lily pond with the number of leaves doubling each day. The teacher asks when is the pond 1/2 full if it is full on the 30th day and the answer is "on the 29th day." The world now with a population of 4 billion may already be at least 1/2 full. If doubling of population occurs within the next generation the "pond" could be entirely full. A doubling of population would mean that a great majority of countries will be confronted with ecological economic and political stresses that may be unmanageable. Signs of stress on the worlds principal biological systems and energy resources indicate that in many places they have already reached their limit and simply cannot withstand a tripling or quadrupling of population pressures. Population growth multiplies the number of people who are in need of social essentials at the same time it reduces the resources able to satisfy them. Attention here is focused on understanding the threat of population growth the dimensions of ecological stresses and the consequences the impact of population growth on food needs and economic stresses. The question remains as to how humankind will accommodate to the earths natural systems and resources. Although analysts can define the elements of accommodation and prepare the timetables for making the required changes only governments have sufficient power to implement them by means of legislation budgetary and fiscal policies taxation and the analytical and educational capacities of government institutions.