Earth and Sky:Global Warming and Ozone 全球变暖和臭氧

Global Warming and Ozone¹ 全球变暖和臭氧

Could the coming century bring a new threat to the ozone layer? Discover one scientist's model of the effect of global warming and greenhouse gases on ozone -- on today's Earth and Sky.

DB: This is Earth and Sky.

JB: After 30 years of steady decline, Earth's ozone layer is thinner but seems to be stable. A ban on ozone-depleting CFCs is largely responsible. Computer modeling gives reason to hope for an almost full recovery of Earth's ozone layer within 60 years. But this sort of modeling is difficult -- and its predictions aren't iron-clad.

DB: And some models show the ozone layer could face a new threat -- from global warming. Drew Shindell, an atmospheric² scientist at NASA's Goddard Institute for Space Studies in New York City, talked with us about his computer models of climate.

Drew Shindell: So we get this combination of temperature change and methane³ changes, water vapor⁴ changes, we have changes in reactive nitrogen species -- which come from another greenhouse gas -- and all of these things put together end up leading to a net decrease in the amount of ozone in the lower stratosphere.

JB: So if the world gets warmer, stratospheric ozone might be depleted⁵ again -- by 5 to 10 percent -- a return to today's low levels. What could be done then to protect the ozone layer?

Drew Shindell: Well, we would have to control greenhouse gas emissions⁶ and certainly that is a much more complicated problem -- and a much bigger change in economic systems and such -- than it was to change the CFCs.

DB: Special thanks today to NASA's Earth Science Enterprise. We're Block and Byrd for Earth and Sky.

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 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。

3 methane   

n.甲烷，沼气

参考例句：

• The blast was caused by pockets of methane gas that ignited.爆炸是由数袋甲烷气体着火引起的。
• Methane may have extraterrestrial significance.甲烷具有星际意义。

4 vapor   

n.蒸汽，雾气

参考例句：

• The cold wind condenses vapor into rain.冷风使水蒸气凝结成雨。
• This new machine sometimes transpires a lot of hot vapor.这部机器有时排出大量的热气。

5 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。

6 emissions   

排放物( emission的名词复数 )； 散发物（尤指气体）

参考例句：

• Most scientists accept that climate change is linked to carbon emissions. 大多数科学家都相信气候变化与排放的含碳气体有关。
• Dangerous emissions radiate from plutonium. 危险的辐射物从钚放散出来。