泛读英语第四册unit2课文及翻译

泛读英语第四册unit2课文及翻译 The Population Surprise(出人意料的人口变化) Text 1 The Population Surprise by Max Singer Will the world's population keep increasing as commonly believed? What are the factors that account for its change? Please read the following article and make out its viewpoints. Fifty years from now the world's population will be declining, with no end in sight. Unless people's values change greatly, several centuries from now there could be fewer people living in the entire world than in the United States today. The big surprise of the past twenty years is that in not one country did fertility stop falling when it reached the replacement rate , 2.1 children per woman. In Italy, for example, the rate has fallen to 1.2. In Western Europe as a whole and in Japan it is down to 1.5. The evidence now indicates that within fifty years or so world population will peak at about eight billion before starting a fairly rapid decline. Because in the past two centuries world population has increased from one billion to nearly six billion, many people still fear that it will keep “exploding” until there are too many people for the earth to support. But that is like fearing that your baby will grow to 1 000 pounds because its weight doubles three times in its first seven years. World population was growing by two percent a year in the 1960s; the rate is now down to one percent a year, and if the patterns of the past century don't change radically, it will head into negative numbers. This view is coming to be widely accepted among population experts, even as the public continues to focus on the threat of uncontrolled population growth. As long ago as September of 1974 Scientific American published a special issue on population that described what demographers1 had begun calling the “demographic transition” from traditional high rates of birth and death to the low ones of modern society. The experts believed that birth and death rates would be more or less equal in the future, as they had been in the past, keeping total population stable after a level of 10-12 billion people was reached during the transition. Developments over the past twenty years show that the experts were right in thinking that population won't keep going up forever. They were wrong in thinking that after it stops going up, it will stay level. The experts' assumption that population would stabilize because birth rates would stop falling once they matched the new low death rates has not been borne out by experience. Evidence from more than fifty countries demonstrates what should be unsurprising: in a modern society the death rate doesn't determine the birth rate. If in the long run birth rates worldwide do not conveniently match death rates, then population must either rise or fall, depending on whether birth or death rates are higher. Which can we expect? The rapid increase in population during the past two centuries has been the result of lower death rates, which have produced an increase in worldwide life expectancy2 from about thirty to about sixty-two. (Since the maximum , if we do not change fundamental human physiology , is about eighty-five, the world has already gone three fifths as far as it can in increasing life expectancy.) For a while the result was a young population with more mothers in each generation, and fewer deaths than births. But even during this population explosion the average number of children born to each woman , the fertility rate , has been falling in modernizing societies. The prediction that world population will soon begin to decline is based on almost universal human behavior. In the United States fertility has been falling for 200 years (except for the blip of the Baby Boom3), but partly because of immigration it has stayed only slightly below replacement level for twenty-five years. Obviously, if for many generations the birth rate averages fewer than 2.1 children per woman, population must eventually stop growing. Recently the United Nations Population Division estimated that 44 percent of the world's people live in countries where the fertility rate has already fallen below the replacement rate, and fertility is falling fast almost everywhere else. In Sweden and Italy fertility has been below replacement level for so long that the population has become old enough to have more deaths than births. Declines in fertility will eventually increase the average age in the world, and will cause a decline in world population forty to fifty years from now. Because in a modern society the death rate and the fertility rate are largely independent of each other, world population need not be stable. World population can be stable only if fertility rates around the world average out to 2.1 children per woman. But why should they average 2.1, rather than 2.4, or 1.8, or some other number? If there is nothing to keep each country exactly at 2.1, then there is nothing to ensure that the overall average will be exactly 2.1. The point is that the number of children born depends on families' choices about how many children they want to raise. And when a family is deciding whether to have another child, it is usually thinking about things other than the national or the world population. Who would know or care if world population were to drop from, say, 5.85 billion to 5.81 billion? Population change is too slow and remote for people to feel in their lives , even if the total population were to double or halve in only a century. Whether world population is increasing or decreasing doesn't necessarily affect the decisions that determine whether it will increase or decrease in the future. As the systems people would say, there is no feedback loop. What does affect fertility is modernity. In almost every country where people have moved from traditional ways of life to modern ones, they are choosing to have too few children to replace themselves. This is true in Western and in Eastern countries, in Catholic and in secular societies. And it is true in the richest parts of the richest countries. The only exceptions seem to be some small religious communities. We can't be sure what will happen in Muslim countries4, because few of them have become modern yet, but so far it looks as if their fertility rates will respond to modernity as others' have. Nobody can say whether world population will ever dwindle to very low numbers; that depends on what values people hold in the future. After the approaching peak, as long as people continue to prefer saving effort and money by having fewer children, population will continue to decline. (This does not imply that the decision to have fewer children is selfish; it may, for example, be motivated by a desire to do more for each child.) Some people may have values significantly different from those of the rest of the world, and therefore different fertility rates. If such people live in a particular country or population group, their values can produce marked changes in the size of that country or group, even as world population changes only slowly. For example, the U.S. population, because of immigration and a fertility rate that is only slightly below replacement level, is likely to grow from 4.5 percent of the world today to 10 percent of a smaller world over the next two or three centuries. Much bigger changes in share are possible for smaller groups if they can maintain their difference from the average for a long period of time. (To illustrate: Korea's population could grow from one percent of the world to 10 percent in a single lifetime if it were to increase by two percent a year while the rest of the world population declined by one percent a year.) World population won't stop declining until human values change. But human values may well change , values, not biological imperatives, are the unfathomable variable in population predictions. It is quite possible that in a century or two or three, when just about the whole world is at least as modern as Western Europe is today, people will start to value children more highly than they do now in modern societies. If they do, and fertility rates start to climb, fertility is no more likely to stop climbing at an average rate of 2.1 children per woman than it was to stop falling at 2.1 on the way down. In only the past twenty years or so world fertility has dropped by 1.5 births per woman. Such a degree of change, were it to occur again, would be enough to turn a long-term increase in world population of one percent a year into a long-term decrease of one percent a year. Presumably fertility could someday increase just as quickly as it has declined in recent decades, although such a rapid change will be less likely once the world has completed the transition to modernity. If fertility rises only to 2.8, just 33 percent over the replacement rate, world population will eventually grow by one percent a year again , doubling in seventy years and multiplying by twenty in only three centuries. The decline in fertility that began in some countries, including the United States, in the past century is taking a long time to reduce world population because when it started, fertility was very much higher than replacement level. In addition, because a preference for fewer children is associated with modern societies, in which high living standards make time valuable and children financially unproductive and expensive to care for and educate, the trend toward lower fertility couldn't spread throughout the world until economic development had spread. But once the whole world has become modern, with fertility everywhere in the neighborhood of replacement level, new social values might spread worldwide in a few decades. Fashions in families might keep changing, so that world fertility bounced above and below replacement rate. If each bounce took only a few decades or generations, world population would stay within a reasonable narrow range , although probably with a long-term trend in one direction or the other. The values that influence decisions about having children seem, however, to change slowly and to be very widespread. If the average fertility rate were to take a long time to move from well below to well above replacement rate and back again, trends in world population could go a long way before they reversed themselves. The result would be big swings in world population , perhaps down to one or two billion and then up to 20 to 40 billion. Whether population swings are short and narrow or long and wide, the average level of world population after several cycles will probably have either an upward or a downward trend overall. Just as averaging across the globe need not result in exactly 2.1 children per woman, averaging across the centuries need not result in zero growth rather than a slowly increasing or slowly decreasing world population. But the long-term trend is less important than the effects of the peaks and troughs5 . The troughs could be so low that human beings become fewer than they were in ancient times. The peaks might cause harm from some kinds of shortages. One implication is that not even very large losses from disease or war can affect the world population in the long run nearly as much as changes in human values do. What we have learned from the dramatic changes of the past few centuries is that regardless of the size of the world population at any time, people's personal decisions about how many children they want can make the world population go anywhere , to zero or to 100 billion or more. (1916words) 课文一 出人意料的人口变化 马克斯?辛格 世界人口会象人们通常认为的那样持续增长吗,造成人口变化的因素是什么,请阅读下面的文章，并 弄清其观点。 现在起五十年后，世界人口将会减少，而且还 看不到终止的迹象。除非人们的价值观产生巨大变化，否则几个世纪后，生活在整个地球上的人口可能会比今天生活在美国的还要少。 每个过去二十年最令人吃惊的事情是，没有一个国家当其出生率降到人口置换率水平时——妇女生育2.1个子女——就停止下降了。例如，在意大利，该比率已降到1.2。整个西欧和日本降至1.5。现在的证据显示大约五十年内世界人口将达到八十亿的顶点，然后将开始相当迅速地减 少。 因为在过去的两个世纪内，世界人口已从十亿增至将近六十亿，许多人害怕人口还会爆炸式增长，直到地球无法负担庞大的人口。但是，这就好象担心因为你的宝宝在最初的七年内体重翻了六倍，他就会长到一千磅。在六十年代，世界人口每年只增长2%，现在这一比率已降到每年1%。如果上个世纪的生育模式没有根本性变化的话，这将会导致人口的负增长。尽管公众们继续把目光集中在失控的人口增长带来的危险上，上述观点已开始被人口学专家普遍接受。 早在1974年9月，《美国科学》杂志发行了一份人口研究专号，描述了人口学家开始将之称为“人口过渡期”的情况，即从传统的高出生率和死亡率转到现代社会的低出生率和死亡率。专家们当时相信，将来的出生率和死亡率会和过去一样大体相等，这样，在过渡期内人口达到一百至一百二十亿这样一个水平后，整个人口将会保持稳定。 过去二十年的发展明，专家们认为人口不会永远增长这一观点是正确的。但他们认为人口停止增长后就会维持该水平却是错误的。专家们推测出生率一旦同新的低死亡率达到平衡后就会停止衰减，所以人口能够保持稳定，这种推测没有得到经验的证实。来自五十多个国家的证据显示了一个并不令人惊讶的结论:在现代社会，死亡率并不能决定出生率。长远地看，如果世界范围内出生率不能与死亡率适当保持平衡，那么人口将肯定或者增长或者减少，这取决于出生率高还是死亡率高。我们预计会看到什么呢, 过去两个世纪内人口快速增长是由于低死亡率造成的，这使得世界范围内的人均寿命从约三十岁增至约六十二岁(因为如果我们不改变人类的基本生理构造的话，最高人均寿命约为八十五岁，所以世界人均寿命的增幅已达到最大可能性的五分之三)。这在一段时期内造成的结果就是人口的年轻化，每一代中母亲的数量将会更多，死亡人口少于出生人口。但是即使在这段人口爆炸期间，现代社会中平均每位女性所生育的子女数(出生率)仍在下降。基于几乎是人类的普遍行为，我们预测出世界人口将开始衰减。美国二百多年来生育率一直在下降(除了二战过后出现的短暂的生育高峰期)，但是在某种程度上受移民的影响，在25年里它只略低于人口置换率。 很明显，如果许多代平均出生率一直低于每个妇女生育2.1个子女，人口最终一定会停止增长。最近，联合国人口署预测，世界44%的人口居住在那些出生率已经低于人口置换率的国家中，而在除此之外的几乎世界各地，出生率都在快速下降。在瑞典和意大利，出生率早就长期低于置换率，以致于人口老龄化，死亡人数多于出生人数。出生率的降低使世界人均年龄增长，而且会导致四十至五十年后世界人口的减少。 在现代社会，因为死亡率和出生率在很大程度上是相互独立的，世界人口并不一定要保持稳定。只有世界范围内的出生率能达到平均每位妇女生育2.1个子女，世界人口才可能稳定。但为什么平均出生率一定是2.1，不是2.4或1.8，或其它什么数字,如果无法使每个国家的平均出生率正好控制在2.1，那么就无法保证总体的平均水平正好为2.1。 问题的关键在于，孩子的出生取决于家庭想要养育多少个孩子。一个家庭在决定他们是否还需要一个孩子时通常所考虑的并不是全国或世界的人口数目。谁知道或 是在乎世界人口会不会从50.85亿降到50.81亿这类问题,人口的变化是长期的而且变化微小，即使在仅仅100年间总人口就翻番或减半，人们也很难在生活中感受到。世界人口是否正在增加或减少 未必会影响某些决策的产生，使将来的人口增长或减少。正如一些系统论研究人士会说的那样，这里不存在一种反馈环 。 真正会影响出生率的是现代性。几乎在生活方式已经从传统向现代转变的所有国家中，人们选择的是少生孩子，以致于无法进行人口置换。在西方和东方的国家，在天主教和世俗社会都是如此。在最富庶国家中最富裕的地区同样如此。唯一的例外好象是一些小的宗教社区。我们不清楚穆斯林国家中会发生什么，因为它们几乎都不是现代化国家，但目前看来，其出生率好象也会象其它国家那样对现代性作出呼应。 没有人能肯定世界人口是否会一直减少到非常低的数目，这取决于人们将来的价值取向。在即将到来的人口高峰过后，只要人们仍继续宁愿少生孩子以节省精力和金钱，那么人口将会继续减少。(这并不意味少生孩子的决定是自私的，也许，比如说，这只是出于希望 为每个孩子做更多的事情。) 也许有些人的价值观与世界其它地方的很不一样，所以就会产生不同的出生率。如果这些人生活在特定的某个国家或特定的人口群体中，那么即使世界人口变化很缓慢，他们的价值观也会使该国或群体的人口数目产生显著的变化。例如，美国人口由于受移民影响， 也由于其出生率只是略低于置换水平，所以在将来的二、三百年内，有可能会从目前占世界人口的4.5%增长到世界人口缩减后的10%。对于一些较小的人口群体来说，如果他们长时间内与平均出生率保持差距，那么他们所占世界人口的份额可能会产生更大的变化。(举例来说:如果朝鲜的人口每年增长2%，而世界其它各地的人口每年递减1%，那么仅在一个生命周期内，朝鲜就会从世界人口的1%增加到10%。) 要是人们的价值观不转变，世界人口就不会停止减少。但人类的价值观是会变化的——价值观，而不是生物的必需要求，才是人口预测中不可捉摸的变数。也有可能在一百、两百或三百年后，当几乎整个世界的现代化水平都能达到目前的西欧国家时，相比于当今的现代社会，人们会更看重孩子。如果是这样，那么出生率就会攀升。而且在达到每位女性生育2.1个子女这样一个平均水平后就会停止上升的可能性并不比降到2.1后会停止下降的可能性大多少。 仅在过去的二十年左右时间里，世界人口出生率每个妇女已降低了1.5个。如果再发生如此程度的变化，那么就足以使以前长时间内1%的年世界人口增长率变成长时间内1%的年递减率。也有可能某一天出生率会象最近几十年急速衰减那样急剧增长，虽然一旦整个世界过渡到现代社会之后，出现这样一种急剧变化的可能性要小得多。如果出生率仅增长到2.8，比人口置换率高33%，那么世界人口最终将会有1%的年增长率，即七十年内翻一番，在三个世纪内就能增长20倍。 在过去的一个世纪里，在一些国家中，包括美国，出生率衰减持续了很长一段时间才取得了世界人口减少的效果，因为开始衰减时的出生率比人口置换率要高得多。而且，愿意少生孩子的观念与现代社会相关。现代社会中，高生活水准使得时间变得很宝贵，而生孩子从经济上来说没有效益，养育和教育费用也很昂贵，所以只有当经济在世界范围内得到发展后，低出生率的潮流才会遍及世界。但是一旦整个世界都成为现代化国家，且任何地方的出生率都与置换率大体相当时，新的社会价值观又会在几十年内传遍全球。家庭方式可能会继续变化，所以世界人口的出生率会在置换率附近上下波动。如果每次波动只需要几十年或几代人的时间(虽然 在其中任一方向的发展可能是长期性的)，世界人口变化会保持在一个合理的、狭窄的范围内。 但是，看起来，影响人们作出生育决定的价值观转变缓慢，却流传很广。如果需要一段漫长时间使平均出生率从远低于置换率升到远高于置换率，然后再使它降下来，那么世界人口的走势会发展得很远，然后才会逆转。其结果就是世界人口的巨大涨落——可能会降到10亿或20亿，然后升到200至400亿。 不管人口的涨落是短期、小范围的或是长期、大范围的，世界人口的平均水平在经过了几个周期之后，总体上会形成一种或上升、或下降的趋势。正如全球范围内妇女生育子女的平均水平不一定要正好达到2.1一样，几个世纪内的人口平均水平也不见得就是零增长，而可能是慢增长或慢衰减。但是与长期的趋势相比，人口波峰与谷底所带来的效应显得更重要。人口达到谷底时，人类数量会比古代还要少。波峰时会由于某种短缺而产生危害。 一个隐含的结论是，即使由于疾病或战争使人口大量减少，它们对世界人口的长远影响也不能与由于人类价值观转变所造成的影响相抗衡。我们从过去几个世纪戏剧性的人口变化中所学到的就是，不管任何时候世界人口是多少，人们愿意生育多少子女的个人抉择，能够 使世界人口发生各种变化——到零，或者到1000亿，或者更多。