英語聽力文摘 臭氧空洞

臭氧層是指大氣層的平流層中臭氧濃度相對較高的部分，其主要作用是吸收短波紫外線。大氣層的臭氧主要以紫外線打擊雙原子的氧氣，把它分為兩個原子，然后每個原子和沒有分裂的氧合并成臭氧。臭氧分子不穩(wěn)定，紫外線照射之后又分為氧氣分子和氧原子，形成一個繼續(xù)的過程臭氧氧氣循環(huán)，如此產生臭氧層。自然界中的臭氧層大多分布在離地20—50千米的高空。臭氧層中的臭氧主要是紫外線制造。

Cleaning Up The Ozone Layer

清理臭氧層

The scientists are devoting all their time to this problem(solving ozone layer depletion) are going to be thrilled.

The problem with the ozone layer is that when certain chemicals, like chlorofluorocarbons, reach the stratosphere, they break down into chlorine and bromine,which react with the ozone and destroy it.

The plan is to somehow clean the stratosphere and get rid of these chemicals. For example, some scientists have suggested using giant lasers on top of mountains to basically break apart harmful chemicals before they reach the stratosphere.

However, research proves that this would be incredibly expensive, not to mention that the side effects aren’t clear. Scrubbing out the chemicals this way might end up causing serious environmental problems.

It would be much easier to stop releasing harmful chemicals into the atmosphere in the first place. One chlorinemolecule can break apart more than one hundred thousand ozonemolecules. Why not keep it from getting there at all? If we stopped releasing harmful chemicals today, the ozone layer would probably be back at full strength by 2050.

一些科學家花畢生的精力來解決臭氧層損耗的問題，他們將會感到很興奮。

科學家們認為人類造成臭氧層破壞的主要原因是一些化學物質，像氯氟碳，當它們到達平流層后會分解成氯和溴，然后和臭氧發(fā)生化學反應從而破壞臭氧層。

他們計劃將這些化學物質從平流層中清除。例如，有的科學家就建議在有害化學物質到達平流層之前，使用山頂上的巨型激光束從根本上將它們分離。

可是，調查研究研究表明這種方法的成本很高，更何況產生的副作用還不清楚。用這種方法清除化學物質可能會導致嚴重的環(huán)境問題。

首先，停止向大氣中排放有害化學物質是比較簡單易行的辦法。一個氯分子可以分解十萬多個臭氧分子。為什么不阻止氯到達臭氧層呢?如果我們現(xiàn)在停止排放有害化學物質，也許到了2050年，臭氧層空洞就會消失了。