考研阅读精选：世界人口到10月底将会达到70亿

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世界人口到10月底将会达到70亿
The world’s population will reach 7 billion at the end of October. Don’t panic

  IN 1950 the whole population of the earth—2.5 billion—could have  squeezed, shoulder to shoulder, onto the Isle of Wight, a  381-square-kilometre rock off southern England. By 1968 John Brunner, a  British novelist, observed that the earth’s people—by then 3.5  billion—would have required the Isle of Man, 572 square kilometres in  the Irish Sea, for its standing room. Brunner forecast that by 2010 the  world’s population would have reached 7 billion, and would need a bigger  island. Hence the title of his 1968 novel about over-population, “Stand  on Zanzibar” (1,554 square kilometres off east Africa).
  Brunner’s prediction was only a year out. The United Nations’ population  division now says the world will reach 7 billion on October 31st 2011  (America’s Census Bureau delays the date until March 2012). The UN will  even identify someone born that day as the world’s 7 billionth living  person. The 6 billionth, Adnan Nevic, was born on October 12th 1999 in  Sarajevo, in Bosnia. He will be just past his 12th birthday when the  next billion clicks over.
That makes the world’s population  look as if it is rising as fast as ever. It took 250,000 years to reach 1  billion, around 1800; over a century more to reach 2 billion (in 1927);  and 32 years more to reach 3 billion. But to rise from 5 billion (in  1987) to 6 billion took only 12 years; and now, another 12 years later,  it is at 7 billion (see chart 1). By 2050, the UN thinks, there will be  9.3 billion people, requiring an island the size of Tenerife or Maui to  stand on.
Odd though it seems, however, the growth in the  world’s population is actually slowing. The peak of population growth  was in the late 1960s, when the total was rising by almost 2% a year.  Now the rate is half that. The last time it was so low was in 1950, when  the death rate was much higher. The result is that the next billion  people, according to the UN, will take 14 years to arrive, the first  time that a billion milestone has taken longer to reach than the one  before. The billion after that will take 18 years.
Once upon a  time, the passing of population milestones might have been cause for  celebration. Now it gives rise to jeremiads. As Hillary Clinton’s  science adviser, Nina Fedoroff, told the BBC in 2009, “There are  probably already too many people on the planet.” But the notion of “too  many” is more flexible than it seems. The earth could certainly not  support 10 billion hunter-gatherers, who used much more land per head  than modern farm-fed people do. But it does not have to. The earth might  well not be able to support 10 billion people if they had exactly the  same impact per person as 7 billion do today. But that does not  necessarily spell Malthusian doom, because the impact humans have on the  earth and on each other can change.