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  • General

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  • 人口增长

    A diverse group of six children standing together outdoors, smiling, in a grassy area.

     

    How fast is human population growing?
    ::人口增长速度有多快?

    There are more than 7 billion people in the world. As you read this sentence, at least three more people will be added. Think about that for second or so, and there’s another three. Why is the human  population  growing so fast? Has it always grown this fast? What causes populations to grow?
    ::全世界人口超过70亿。 当你读到这句话时,至少还会增加3人。想想第二或第二左右,还有3人。为什么人口增长如此之快?人口是否一直如此快速增长?是什么原因导致人口增长?

    Human Population Numbers
    ::人 人 人 人口数

    Bacteria in a dish with ample  nutrients  double in population until there is no more space. Every population eventually reaches its maximum size. The population of bacteria in the dish reaches its  carrying capacity . The  carrying capacity  is the number of an organisms that can live with the resources that are available. The  limiting factor  for the bacteria in the dish is space. That's the factor that limits the population of the bacteria in the dish. If there were unlimited space then maybe nutrients would be the limiting factor. Some resource will always run out to limit a population. Let's now apply these concepts to the human population.
    ::含有大量营养元素的细菌 细菌 细菌 细菌 细菌 细菌 细菌 细菌 细菌 细菌 细菌 细菌 细菌 细菌 细菌 细菌 细菌 细菌 细菌 细菌 细菌 细菌 细菌 细菌 细菌 细菌 细菌 细菌 细菌 细菌 细菌 细菌 细菌 细菌 细菌 细菌 细菌 细菌 细菌 细菌 细菌 细菌 细菌 细菌 细菌 细菌 细菌 细菌 细菌 细菌 细菌 细菌 细菌 细菌 细菌 细菌 细菌 细菌 细菌 细菌 细菌 细菌 细菌 细菌 细菌 细菌 细菌 的 细菌 细菌 细菌 细菌 细菌 细菌 细菌 细菌 细菌 的 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物 生物

    Human population growth over the past 10,000 years has been tremendous ( Figure   ). The entire human population was estimated to be:
    ::过去10 000年来,人类人口增长巨大(图)。

    • 5 million in 8000 BC
      ::公元前8000年中的500万
    • 300 million in 1 AD
      ::1个AD中3亿
    • 1 billion in 1802
      ::1802年的10亿
    • 3 billion in 1961
      ::1961年30亿
    • 7 billion in 2011
      ::2011年70亿

    Graph showing human population growth from 10,000 BC to 2000 AD with exponential increase.

     

    Human population from 10,000 BC through 2000 AD. This shows the exponential increase in human population that has occurred in the last few centuries.
    ::从公元前10 000公元后至2000年,人类人口从10 000名增长到2000年,这表明在过去几个世纪中,人类人口呈指数式增长。

    The Rate of Growth
    ::增长率

    Not only has the population increased, but the rate of population growth has increased ( Figure   ). The population was estimated to reach 7 billion in 2012, but it did so in 2011. This was just 12 years after reaching 6 billion.
    ::人口不仅增加了,而且人口增长率也提高了(图 ) 。 2012年人口估计达到70亿,2011年却做到了这一点。 仅仅12年,人口增长率就达到了60亿。

    Bar graph showing years between billion population milestones, highlighting rapid population growth.

     

    The amount of time between the addition of each one billion people to the planet’s population, including speculation about the future. Already, the population reached 7 billion one year earlier than projected.
    ::地球人口每增加10亿人口之间的时间间隔,包括对未来的猜测。 人口比预测早一年达到70亿。

    As the human population continues to grow, different factors limit population in different parts of the world. Space, clean air, clean  water , and food to feed everyone are limiting in some locations. Worldwide though, human ingenuity has not placed a limit on the population. Not only does the population increase, the rate of population growth increases.
    ::随着人口继续增长,不同的因素限制了世界不同地区的人口,空间、清洁空气、清洁水和供人食用的食物在某些地方受到限制,但在世界范围内,人类的聪明才智并没有限制人口,不仅人口增长,人口增长率也有所上升。

    There is a sign that population growth is slowing. Although population continues to grow rapidly, the rate that the growth rate is increasing has declined. Still, a recent estimate by the United Nations claims that 10.1 billion people will be sharing this  planet  by the end of the century. The total added will be about 3 billion people. That number is more than were even in existence as recently as 1960. Yet that is much less than the number we would expect if 1 billion people were being added every 12 years.
    ::有迹象表明人口增长正在放缓。 尽管人口继续快速增长,但增长率正在上升的速率已经下降。 尽管如此,联合国最近估计到本世纪末将有1010亿人口共享这个星球,新增人口总数约为30亿,这一数字比1960年时还多。 但是,这一数字远远低于每12年增加10亿人的预期数字。

    Summary
    ::摘要

    • The human population is growing more than exponentially.
      ::人口正在成倍增长。
    • The rate of human population growth is still increasing. However, the rate at which the rate of growth is increasing has declined.
      ::人口增长率仍在上升,但增长率的增长率却在下降。
    • The United Nations estimates a population of 10.1 billion by the end of the century.
      ::联合国估计,到本世纪末,人口将达到1010亿。

    Review
     ::回顾

    1. What does it mean that the human population growth rate is increasing?
      ::人口增长率在上升意味着什么?
    1. What does it mean that the rate that the growth rate is increasing has declined?
      ::增长率的增长率下降意味着什么?
    1. Looking at the graph above: When did the human population start to really grow? When did it really take off?
      ::上图显示:人类人口何时开始真正增长?它何时真正起飞?

    Explore More
    ::探索更多

    Use the resource below to answer the questions that follow.
    ::利用以下资源回答以下问题。

    1. What was the population in 1800?
      ::1800年的人口是多少?
    1. What was the population in 1930?
      ::1930年的人口是多少?
    1. What number did the population reach in 2011?
      ::2011年人口达到多少?
    1. What could the population be in 2045?
      ::2045年的人口会是什么?
    1. What is the average lifespan of people today?
      ::今天人们的平均寿命是多少?
    1. What was the average lifespan of people in 1960?
      ::1960年人们的平均寿命是多少?
    1. What is a megacity?
      ::什么是大城市?
    1. How many megacities were there in 1975?
      ::1975年有多少个特大城市?
    1. How many megacities are there now?
      ::现在有多少个特大城市?
    1. Explain what the world needs. What does that mean?
      ::解释一下世界需要什么 这是什么意思?
    1. How much of the population lacks adequate sanitation?
      ::有多少人口缺乏适当的卫生设施?