未来人口增长

Does the world seem crowded?
::世界看起来人多吗?

In some places, there seem to be people everywhere. Times Square in New York City is definitely one of those places. In other places, there are hardly any people at all. Does that mean that the world is not overpopulated? Is space all that people need?
::在某些地方,似乎到处都有人。纽约时报广场绝对就是其中之一。在其他地方,几乎没有人。这是否意味着世界没有人口过多?人们需要的空间是否都足够?

Growth Rates Around the World
::全世界增长率

With ample food, better health, and easier work, people live longer. Children are much more likely to reach adulthood and have their own children. In many countries, death rates have gone down dramatically, but birth rates remain high. This means that the  population  is growing. Pictured below is the growth rates of human populations all over the world ( Figure   ).
::有了充足的食物、更好的健康和更轻松的工作,人们的寿命就会更长。 儿童更有可能成年并拥有自己的孩子。 在许多国家,死亡率已经大幅下降,但出生率仍然很高。 这意味着人口正在增长。 下面是全世界人口的增长率(图 ) 。

The Future
::未来 未来

Human ingenuity has allowed the population to continue to grow. We’ve increased Earth's  carrying capacity  for humans by our genius. We grow crops, trade for needed materials, and design ways to exploit resources that are difficult to get at, such as  . We use long-buried ancient organisms for  fuel . We have broken the rules for biological populations.
::人类的聪明才智使得人口得以继续增长。 我们的天才增加了地球人类的承载能力。 我们种植作物,交换所需材料,并设计开发难以获取的资源的方法,比如 。 我们用长期埋没的古代生物作为燃料。 我们已经打破了生物群的规则。

Of course, there's a flip side to this. For the population to continue to grow, more advances in agriculture will be needed. The best lands are already in use. Most  rivers  that can be dammed, have been dammed. In many  aquifers , groundwater is not replenished on the time frame needed.  Fossil fuels  too are limited. Obtaining fossil fuels or developing new power sources will be more costly.
::当然,有相反的一面。 人口要继续增长, 农业需要更多进步。 最好的土地已经投入使用。 大部分河水被淹没了。 在许多地下蓄水层中,地下水没有在必要的时间范围内得到补充。 化石燃料也很有限。 获取化石燃料或开发新的电源的成本会更高。

Future Population Growth
::未来人口增长

The rate of increase of the growth rate of the human population is decreasing ( Figure   ). The population may stop growing by the mid 2000s. Some scientists think that the human population will peak at about 9 billion people. What will need to change for the population to stop growing then?
::人口增长率的增长率正在下降(图 ) 。 到2000年代中期,人口可能会停止增长。 一些科学家认为,人口将达到90亿的高峰。 人口要停止增长,需要改变什么?

Summary
::摘要

• Humans have exceeded the carrying capacity of Earth for humans by their ingenuity.
  ::人类的聪明才智超过了地球对人类的承载能力。

• The rate of population increase is starting to decline. The population is still exploding though.
  ::人口增长率开始下降,但人口仍在急剧上升。

• The growth rate is higher in less developed nations.
  ::较不发达国家的增长率较高。

Review
::回顾

1. How does the human population exceed the natural carrying capacity of a region for humans?
   ::人类人口如何超过一个区域人类的自然承载能力?

1. Are we exceeding the carrying capacity of the entire planet?
   ::我们是否超过了整个地球的承载能力?

1. Where is the human population growing the most? Where is it growing the least or not growing?
   ::人口增长最多的是哪里?增长最少还是没有增长?

1. Why does the population graph level out and then decline a bit? Is that pattern certain? What is it based on?
   ::为什么人口图表水平水平会下降一点?这种模式是否确定?它基于什么?

1. What other population growth patterns are possible?
   ::还有什么其他人口增长模式可能?

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. How many people will Earth need to support by 2050?
   ::到2050年,地球需要支持多少人?

1. How come there will be so many?
   ::为什么会有这么多人?

1. Where will most of the population growth occur?
   ::大多数人口增长将在哪里发生?

1. Which country's population will shrink?
   ::哪个国家的人口会减少?

1. What country's population will triple?
   ::哪个国家的人口将增加三倍?

1. In terms of economic stability, where will most of the population growth be?
   ::就经济稳定而言,人口增长的大部分将在哪里?

1. What kept our population in check in the past?
   ::过去是什么使我们的人口处于停滞状态?