Study: Loss of Ozone Slows

By Caty Weaver¹
Broadcast: September 12, 2003
This is Bob Doughty² with the VOA Special English Environment Report.
Scientists in the United States have reported some good news about the 1)ozone³ in the atmosphere. Recent findings suggest that the destruction of ozone by pollution is slowing. Ozone is a form of oxygen. Its presence above Earth protects us from radiation from the sun.
In one study, researchers examined information gathered by NASA space agency satellites and by equipment on Earth. The findings? In the words of Michael Newchurch of the University of Alabama: "This is the beginning of a recovery of the ozone layer."
Mister Newchurch led the study. He says the atmosphere was losing about eight percent of the ozone layer per ten-year period since the late nineteen-seventies. In the last five years, though, that rate of loss has dropped by half. He says the atmosphere should start to gain ozone before long. He says a full recovery, however, is about fifty years away, as long as the Montreal Protocol⁴ remains⁵ in place.
That is an international treaty from nineteen-eighty-seven to restore the ozone layer. The treaty restricts the use of a number of chemicals that destroy ozone, like chlorofluorocarbons, or C-F-C's.
Wide use of C-F-C's began in the nineteen-thirties. They became popular 2)coolants in 3)devices such as refrigerators and air conditioners. C-F-C's remain in the atmosphere for years.
Mister Newchurch says the study provides evidence that the Montreal Protocol is working by reducing C-F-C pollution. But the study found the ozone improvement only in the upper 4)stratosphere. The scientists have not yet seen evidence of similar changes in the lower stratosphere. That holds most of the protective ozone.
The Montreal Protocol also restricts the use of 5)methyl 6)bromide, a chemical to kill insects. Farmers and shippers are the main users. Natural sources of methyl bromide include oceans and some plants. Scientists say the bromine gas it produces is fifty times more destructive to ozone than 7)chlorine gas from C-F-C's.
Methyl bromide has never been used as widely as C-F-C's. But a separate study found a decrease in bromine gas levels in the atmosphere. Researchers at the National Oceanic and Atmospheric⁶ Administration did the study. They reported a thirteen percent drop since nineteen-ninety-eight.
This VOA Special English Environment Report was written by Caty Weaver. This is Bob Doughty.

注释:
1) ozone [5EuzEun] n.臭氧
2) coolant [5ku:lEnt] n.冷冻剂
3) device [di5vais] n.装置
4) stratosphere [5strAtEusfiE] n.（气）同温层，最上层
5) methyl [ 5mi:Wail] n.甲基，木精
6) bromide [5brEumaid] n.（化）溴化物
7) chlorine [5klC:ri:n] n.（化）氯

1 weaver   

n.织布工；编织者

参考例句：

• She was a fast weaver and the cloth was very good.她织布织得很快，而且布的质量很好。
• The eager weaver did not notice my confusion.热心的纺织工人没有注意到我的狼狈相。

2 doughty   

adj.勇猛的，坚强的

参考例句：

• Most of successful men have the characteristics of contumacy and doughty.绝大多数成功人士都有共同的特质：脾气倔强，性格刚强。
• The doughty old man battled his illness with fierce determination.坚强的老人用巨大毅力与疾病作斗争。

3 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。

4 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。

5 remains   

n.剩余物，残留物；遗体，遗迹

参考例句：

• He ate the remains of food hungrily.他狼吞虎咽地吃剩余的食物。
• The remains of the meal were fed to the dog.残羹剩饭喂狗了。

6 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。