VOA慢速英语--联合国报告称地球臭氧层愈合中

United Nations Report Says Earth’s Ozone¹ Layer Is Healing

A new study says the protective layer of the Earth’s atmosphere is finally healing from damage by humans’ use of harmful chemicals.

Aerosol² sprays and coolants had been thinning the ozone layer since the 1970s. After scientists raised concerns about ozone-reducing chemicals, people and companies around the world stopped using them.

What is the ozone layer?

Ozone is a colorless combination of three oxygen atoms. The ozone layer starts at about 10 kilometers above Earth and stretches nearly 40 kilometers higher. The ozone layer is important because it protects Earth from the sun’s ultraviolet rays, which cause skin cancer, crop damage and other problems.

But man-made chemicals – called chlorofluorocarbons, or CFCs – can damage the ozone layer. In 1987, countries around the world agreed in the Montreal Protocol³ to end the use of CFCs over time.

What the study shows

The United Nations released a study on the effects of the decreased use of CFCs at a conference in Quito, Ecuador in early November.

The study found that the upper ozone layer above the Northern Hemisphere should be completely repaired in the 2030s. The huge Antarctic ozone hole should disappear in the 2060s. The Southern Hemisphere should be healed by about the 2050s, the study showed.

Paul Newman is the chief Earth scientist at NASA’s Goddard Space Flight Center and co-leader of the study. He told the Associated Press the findings are good news.

“If ozone-depleting⁴ substances had continued to increase, we would have seen huge effects,” said Newman. “We stopped that.”

Newman noted⁵ that, at its worst in the late 1990s, about 10 percent of the upper ozone layer was depleted⁶. Since 2000, the ozone layer has increased by about 1 to 3 percent every ten years, the report said.

This year, the ozone hole over the South Pole measured nearly 24.8 million square kilometers in area. That is about 16 percent smaller than the biggest hole recorded — 29.6 million square kilometers in 2006.

The hole reaches its largest size during September and October, when the Southern Hemisphere has its spring. The hole disappears by late December.

If nothing had been done to stop the thinning, the world would have destroyed two-thirds of its ozone layer by 2065, Newman said.

But the changes are not a complete success yet, said a University of Colorado atmospheric⁷ science professor. Brian Toon, who was not part of the report, pointed⁸ to some ozone measurements that have not increased yet.

“We are only at a point where recovery may have started,” said Toon.

The report noted another problem: New technology has found that a banned CFC is being used in East Asia.

How has the hole in the ozone layer affected⁹ global warming?

On its own, the ozone hole has slightly helped protect Antarctica from the effects of global warming. Ross Salawitch is a University of Maryland atmospheric scientist who helped write the report. He said an undamaged ozone layer would actually trap greenhouse gases that cause global warming. Antarctica has heated up, but not as much as it likely would without the decrease of the ozone layer.

Salawitch said scientists do not know how much a healed ozone hole will continue to warm Antarctica. But they do know that decreasing the ozone layer would severely¹⁰ damage the world and human health. Not permitting the ozone layer to heal “would be incredibly irresponsible,” he said.

NASA’s Paul Newman points to another step humans can take: The chemicals that have replaced CFCs need to be replaced with chemicals that do not worsen global warming. An amendment¹¹ to the Montreal Protocol that goes into effect next year would cut some of those gases.

“I don’t think we can do a victory lap until 2060,” Newman said. “That will be for our grandchildren to do.”

I’m Pete Musto.

Words in This Story

layer – n. an amount of something that is spread over an area

aerosol spray(s) – n. a substance that is kept in a container under pressure and that is released as a stream of very small drops when a button is pressed

coolant(s) – n. a liquid that is used to cool an engine or machine

ultraviolet ray(s) – n. rays of light that cannot be seen and that are slightly shorter than the rays of violet light

hemisphere – n. a half of the Earth

depleting – v. greatly reducing the amount of something

greenhouse gas(es) – n. any gas that adds to global warming by trapping infrared¹² radiation

replace(d) – v. to be used instead of something

amendment – n. a change in the words or meaning of a law or document

victory lap – idm. a celebratory act

1 ozone   

n.臭氧，新鲜空气

参考例句：

• The ozone layer is a protective layer around the planet Earth.臭氧层是地球的保护层。
• The capacity of ozone can adjust according of requirement.臭氧的产量可根据需要或调节。

2 aerosol   

n.悬浮尘粒，气溶胶，烟雾剂，喷雾器

参考例句：

• They sprayed aerosol insect repellent into the faces of police.他们将喷雾驱虫剂喷在了警察的脸上。
• Aerosol particles affect visibility,climate,and our health and quality of life.气溶胶对大气能见度、气候变化以及人类健康等有重要影响。

3 protocol   

n.议定书，草约，会谈记录，外交礼节

参考例句：

• We must observe the correct protocol.我们必须遵守应有的礼仪。
• The statesmen signed a protocol.那些政治家签了议定书。

4 depleting   

使大大的减少，使空虚( deplete的现在分词 )； 耗尽，使枯竭

参考例句：

• Regulations are outlawing certain refrigerants, such as chlorofluorocarbons, which contain ozone-depleting chemicals. 随后出台的政策禁用了部分制冷剂，如破坏臭氧层的氟氯碳化合物。
• Aging, being a series of continual losses, can be keenly depleting. 老龄化，作为一个系列的连续亏损，可以清楚地消耗。

5 noted   

adj.著名的，知名的

参考例句：

• The local hotel is noted for its good table.当地的那家酒店以餐食精美而著称。
• Jim is noted for arriving late for work.吉姆上班迟到出了名。

6 depleted   

adj. 枯竭的, 废弃的 动词deplete的过去式和过去分词

参考例句：

• Food supplies were severely depleted. 食物供应已严重不足。
• Both teams were severely depleted by injuries. 两个队都因队员受伤而实力大减。

7 atmospheric   

adj.大气的，空气的；大气层的；大气所引起的

参考例句：

• Sea surface temperatures and atmospheric circulation are strongly coupled.海洋表面温度与大气环流是密切相关的。
• Clouds return radiant energy to the surface primarily via the atmospheric window.云主要通过大气窗区向地表辐射能量。

8 pointed   

adj.尖的，直截了当的

参考例句：

• He gave me a very sharp pointed pencil.他给我一支削得非常尖的铅笔。
• She wished to show Mrs.John Dashwood by this pointed invitation to her brother.她想通过对达茨伍德夫人提出直截了当的邀请向她的哥哥表示出来。

9 affected   

adj.不自然的，假装的

参考例句：

• She showed an affected interest in our subject.她假装对我们的课题感到兴趣。
• His manners are affected.他的态度不自然。

10 severely   

adv.严格地；严厉地；非常恶劣地

参考例句：

• He was severely criticized and removed from his post.他受到了严厉的批评并且被撤了职。
• He is severely put down for his careless work.他因工作上的粗心大意而受到了严厉的批评。

11 amendment   

n.改正，修正，改善，修正案

参考例句：

• The amendment was rejected by 207 voters to 143.这项修正案以207票对143票被否决。
• The Opposition has tabled an amendment to the bill.反对党已经就该议案提交了一项修正条款。

12 infrared   

adj./n.红外线(的)

参考例句：

• Infrared is widely used in industry and medical science.红外线广泛应用于工业和医学科学。
• Infrared radiation has wavelengths longer than those of visible light.红外辐射的波长比可见光的波长长。