Section outline

  • General

    Collapse all Expand all

  • 农业与人口增长

    Chickens in cages on multi-level racks in an industrial farming facility.
     

    What's your vision of a chicken farm?
    ::你对养鸡场有什么看法?

    In many nations, farming today is industrial, growing the maximum amount of food for the minimum price, often without much thought as to the long-term social or environmental consequences. These industrial food production plants are a long way from the farms of the past.
    ::在许多国家,今天的农业是工业化的,以最低价格种植最高粮食量,往往对长期的社会或环境后果置若罔闻。 这些工业粮食生产工厂与过去的农场相去甚远。

    Advances in Agriculture and Population
    ::农业和人口进步

    Every major advance in agriculture has allowed global  population  to increase. Early farmers could settle down to a steady food supply.  Irrigation , the ability to clear large swaths of land for farming efficiently, and the development of farm machines powered by  fossil fuels  allowed people to grow more food and transport it to where it was needed.
    ::农业的每一个重大进步都让全球人口得以增加。 早期农民可以稳定地满足粮食供应。 灌溉、高效清理大片土地供耕用的能力,以及以化石燃料为动力的农机的发展使得人们能够种植更多的粮食并将其运到需要的地方。

    Hunters and Gatherers
    ::猎人和收集者

    What is Earth’s  carrying capacity  for humans? Are humans now exceeding Earth’s carrying capacity for our  species ? Many anthropologists say that the carrying capacity of humans on the  planet  without agriculture is about 10 million ( Figure  ). This population was reached about 10,000 years ago. At the time, people lived together in small bands of hunters and gatherers, hunting for meat and gathering nuts, fruits, and vegetables.
    ::地球承载人类的能力是什么?人类现在是否超越了地球承载我们物种的能力?许多人类学家说,没有农业的地球上人类承载能力约为1,000万(图 ) 。 这一人口大约在一万年前就已经达到。 当时,人们生活在小块猎人和采集者中,猎食和采集坚果、水果和蔬菜。

    A hunter aiming with a bow in a forested landscape.
     
    In a hunter-gatherer society, people relied on the resources they could find where they lived.

    Obviously, human populations have blown past this hypothetical carrying capacity. By using our brains, our erect posture, and our hands, we have been able to manipulate our environment in ways that no other species has ever done. What have been the important developments that have allowed population to grow?
    ::显然,人类已经破灭了这种假设的承载能力。 通过利用我们的大脑、我们的勃起的姿势和双手,我们得以以其他物种从未做过的方式操纵我们的环境。 是什么重要发展使得人口得以增长?

    Farming
    ::农业农业

    About 10,000 years ago, we developed the ability to grow our own food. Farming increased the yield of food plants and allowed people to have food available  year  round. Animals were domesticated to provide meat. With agriculture, people could settle down, so that they no longer needed to carry all their possessions ( Figure ). They could develop better farming practices and store food for when it was difficult to grow. Agriculture allowed people to settle in towns and cities.
    ::大约一万年前,我们发展了自己种植粮食的能力。 农业提高了粮食作物的产量,允许人们全年都有粮食供应。 动物被驯化为家用肉类。 有了农业,人们可以安顿下来,这样他们就不再需要携带所有财产(图 ) 。 他们可以发展更好的耕作方法,在难以种植时储存粮食。 农业允许人们在城镇定居。

    A farmer with two oxen plowing a green field in a rural landscape.
     
    More advanced farming practices allowed a single farmer to grow food for many more people.

    When advanced farming practices allowed farmers to grow more food than they needed for their families ( Figure ), some people were then able to do other types of work, such as crafts or shop keeping.
    ::当先进的耕作做法允许农民种植比家庭所需的更多粮食(图)时,一些人就能够从事其他类型的工作,如手工艺或店铺。

    A combine harvester is collecting crops in a field, enhancing agricultural productivity.
     
    Farming has increasingly depended on machines. Such advanced farming practices allow one farmer to feed many more people than in the past.

    The Industrial Revolution
    ::工业革命

    The next major stage in the growth of the human population was the  Industrial Revolution , which started in the late 1700s ( Figure ). This major historical event marks when products were first mass-produced and when fossil fuels were first widely used for power.
    ::人类人口增长的下一个主要阶段是1700年代末开始的工业革命(图 ) 。 这一重大历史事件标志着产品首次大规模生产,化石燃料首次被广泛用于电力。

    A historical scene depicting a factory during the Industrial Revolution with workers and machinery.
     
    Early in the Industrial Revolution, large numbers of people who had been freed from food production were available to work in factories.

    The Green Revolution
    ::绿色革命

    The  Green Revolution  has allowed the addition of billions of people to the population in the past few decades. The Green Revolution has improved agricultural productivity by:
    ::在过去几十年里,绿色革命使数十亿人能够加入到人口中。 绿色革命通过以下方式提高了农业生产率:

    • Improving crops by selecting for traits that promote productivity; recently, genetically engineered crops have been introduced.
      ::通过选择提高生产力的特征来改进作物;最近引进了转基因工程作物。
    • Increasing the use of artificial fertilizers and chemical  pesticides . About 23 times more fertilizer and 50 times more pesticides are used around the world than were used just 50 years ago ( Figure ).
      ::全世界使用的化肥和化学杀虫剂比仅仅50年前多23倍,杀虫剂比50年前多50倍(图)。
    • Agricultural machinery: plowing, tilling, fertilizing, picking, and transporting are all done by machines. About 17% of the  energy  used each year in the United States is for agriculture.
      ::农业机械:耕种、耕种、施肥、采摘和运输都是由机器完成的。 美国每年使用大约17%的能源用于农业。
    • Increasing access to  water . Many farming regions depend on  , which is not a  renewable resource . Some regions will eventually run out of this water  source . Currently about 70% of the world’s fresh water is used for agriculture.
      ::许多农业地区都依赖 — — 这不是可再生资源。 一些地区最终将耗尽这一水源。 目前,全世界70%的淡水用于农业。 农业是世界农业的源头之一。
    Tractors working on a vast field with rows of crops planted.
     
    Rows of a single crop and heavy machinery are normal sights for modern day farms.

    The Green Revolution has increased the productivity of farms immensely. A century ago, a single farmer produced enough food for 2.5 people, but now a farmer can feed more than 130 people. The Green Revolution is credited for feeding 1 billion people that would not otherwise have been able to live.
    ::绿色革命极大地提高了农场的生产率。 一个世纪前,一个农民生产了2.5人所需的足够粮食,但现在一个农民可以养活130多人。 绿色革命可以用来养活10亿本来无法生存的人。

    The Future
    ::未来 未来

    The flip side to this is that for the population to continue to grow, more advances in agriculture and an ever increasing supply of water will be needed. We’ve increased the carrying capacity for humans by our genius: growing crops, trading for needed materials, and designing ways to exploit resources that are difficult to get at, such as groundwater. And most of these resources are limited.
    ::与此相反的是,要想让人口继续增长,需要农业进步和水供应的不断增加。 我们的天才提高了人类的承载能力:种植作物、买卖所需材料以及设计开发地下水等难以获取的资源的方法。 这些资源大多是有限的。

    The question is, even though we have increased the carrying capacity of the planet, have we now exceeded it ( Figure )? Are humans on Earth experiencing  overpopulation ?
    ::问题是,尽管我们提高了地球的承载能力,但现在我们是否超过了这个能力(图 ) ? 地球上的人类是否人口过多?

    Aerial view of Manhattan showcasing its dense urban development and skyscrapers.
     
    Manhattan is one of the most heavily populated regions in the world.

    There is not yet an answer to that question, but there are many different opinions. In the eighteenth century, Thomas Malthus predicted that human population would continue to grow until we had exhausted our resources. At that point, humans would become victims of famine, disease, or war. This has not happened, at least not yet. Some scientists think that the carrying capacity of the planet is about 1 billion people, not the 7 billion people we have today. The  limiting factors  have changed as our intelligence has allowed us to expand our population. Can we continue to do this indefinitely into the future?
    ::这个问题还没有得到答案,但有许多不同意见。在十八世纪,托马斯·马尔图斯预测,在我们耗尽资源之前,人类人口会继续增长。那时,人类会成为饥荒、疾病或战争的受害者。这种情况还没有发生,至少还没有发生。一些科学家认为,地球的承载能力大约是10亿人口,而不是我们今天拥有的70亿人口。限制因素已经改变,因为我们的智慧使我们得以扩大人口。我们能否继续无限期地在未来这样做呢?

    Summary
    ::摘要

    • Hunters and gatherers lived off the land, with no agriculture, and reached a total population of no more than around 10 million.
      ::猎人和采集者居住在这片土地上,没有农业,总人口不超过1 000万左右。
    • Farming allowed people to settle down and allowed populations to grow.
      ::农业使人们得以安顿下来,人口得以增长。
    • The Green Revolution and the Industrial Revolution are heavily dependent on fossil fuels.
      ::绿色革命和工业革命严重依赖化石燃料。

    Review
    ::回顾

    1. Link major advances in agriculture and industry with changes in the human population.
      ::农业和工业的重大进步与人类人口的变化相联系。
    1. What is carrying capacity? Has the human population exceeded Earth's carrying capacity for humans? If so, how could this have happened?
      ::什么是承载能力?人类人口是否已超过地球载人承载能力?如果超过地球载人承载能力,怎么会发生这种情况?
    1. What is the Green Revolution? How has it affected human population?
      ::绿色革命是什么?它是如何影响人类的?
    1. What do you think of Thomas Malthus' prediction? Have we proven Malthus wrong or have we just not gotten to that point yet?
      ::你觉得托马斯·马尔修斯的预测如何?我们是否证明马尔修斯错了?

    Explore More
    ::探索更多

    Use this resource to answer the questions that follow.
    ::使用此资源回答下面的问题 。

    1. Who was Thomas Malthus?
      ::托马斯·马尔修斯是谁?
    1. What did Malthus think would happen as population increased?
      ::马尔萨斯认为随着人口的增长会发生什么情况?
    1. What did Malthus think would limit population?
      ::马尔萨斯认为什么能限制人口?
    1. What is the Malthusian limit?
      ::马尔修斯的极限是什么?
    1. What is happening to population growth in some developed countries today?
      ::今天,一些发达国家的人口增长正在发生什么情况?
    1. Malthus didn't account for what in his theory?
      ::马尔萨斯没有解释他的理论是什么?
    1. What country is close to the Malthusian limit today?
      ::今天哪个国家接近马尔图斯界限?