万花筒 2011-10-27&10-29 世界人口将超过70亿

 October 31st 2011, that's the date the U.N. says the 7 billionth person will be born on Earth,7 billion.That's a crowded planet¹, says Dr. Jeffrey Sachs, the director of the Earth Institute at Columbia University and author of the Price of Civilization. 

 

It took only 12 years to go from 6 billion to 7 billion and it's expected to take maybe another 14 years to go to 8 billion. So the trajectory² is still rising quickly. 

 

Sachs says all those people mean more demands for food, more stresses on the land, and more loss of water, but that's not the biggest problem. 

 

The big problem is that in the poorest countries, families are still having six,seven,or eight children, that what's putting this tremendous³ growth of population continuing because in the high-income countries, fertility⁴ rates have come down to two children on average or even less.

 

This map shows you birth rates across the world. Multiple⁵ births above five are centered in Africa.Most lower birth rates are in developed countries. Dr. Sachs says rapid population growth in poor countries often creates conflict, and political stress at borders. 

 

And on top of that, cultural values and available health care in developing countries creates a barrier to proper birth control. Dr. Sachs also wrote an in-depth article on the 7 billion mark, and what it could mean for the planet itself. You can find it at cnn.com/opinion.

 

Jim Clancy,CNN Atlanta.

1 planet   

n.行星

参考例句：

• Neptune is the furthest planet from the sun. 海王星是离太阳最远的行星。
• Rubbish, however, is only part of the problem of polluting our planet. 然而, 垃圾只是我们这个星球的污染问题的一个方面。

2 trajectory   

n.弹道，轨道

参考例句：

• It is not difficult to sketch the subsequent trajectory.很容易描绘出它们最终的轨迹。
• The path followed by a projectile is called its trajectory.抛物体所循的路径称为它的轨道。

3 tremendous   

adj.巨大的，极大的；很好的，非常好的

参考例句：

• This book was the outcome of a tremendous amount of scientific work.这本书是大量科学研究工作的成果。
• There is a tremendous difference between them.他们之间有着极大的差别。

4 fertility   

n.肥沃；繁殖力

参考例句：

• A green manure is a crop grown mainly to improve soil fertility.种植绿肥作物主要是为使土壤更加肥沃。
• She is taking drugs to increase her fertility.她为了增强她的生殖能力而在服药。

5 multiple   

adj.多个(或多项、多种)的；n.（数）倍数

参考例句：

• The number 8 is a multiple of 4.八是四的倍数。
• The most common multiple births are twins,two babies born at the same time.最常见的多胎是双胞胎，两个婴儿同时出生。