環境新聞回顧
台灣國際

崔媽媽電子報

【設為首頁】

 

[全球變遷] Healing Our World:Weekly Comment

每週評論:救治我們的世界
生命能否在破裂的臭氧層下生存?

Can Life Survive Earth's Depleted Ozone Layer? 


作者 傑奇艾倫•朱利安諾 博士

地球啊﹗再給我你那最聖潔的禮物吧,從神聖的生命根源流出的寧靜。
我希望再回到我沒有經歷過的生命中,學著回到大自然生命的庫窖。
即使是成為河水所沒有帶走的那塊石頭,是黑的還是潔淨的,都無所謂。
-- 帕波羅•聶努答,智利詩人

  人類一直不願意相信,我們的一舉一動會對整個地球的生態產生影響。畢竟,我們的資源看似耗用不盡,海洋似乎不會枯竭,天空似乎永遠的藍。我們的車怎麼看都不像會對這一切壯麗的美景產生任何威脅。

  但是在過去20年來,累積如山的鐵証已經證實,我們對全球生命的生存權所造成的影響與威脅。

  臭氧層看起來似乎最不會受到人類活動影響。在大氣層中的平流層距離海平面約17到26公里,這一層臭氧層,阻擋了99%來自太陽的有害紫外線進入地球表面。

  西元2000年11月16日在南半球的臭氧層破洞。(圖 美國國家海洋與大氣監控站(NOAA))

  平流層是由氧分--兩個氧原子連結在一起,和來自太陽的紫外線以及閃電的互動所產生。紫外線和閃電將部分的氧原子拆開,分散在相似的氧分子群中。這些四處流竄的氧原子再與氧分子結合,形成具有三個原子的氧。這就是所謂的臭氧。

  紫外線不斷地製造與破壞臭氧,並保護我們免於受到紫外線的傷害。只要製造與破壞臭氧的速度保持平衡,那麼大氣層中的臭氧濃度就應該相對的穩定。

  想一想這個美麗和諧的過程--紫外線可以毀滅所有的生命,但也是紫外線創造了阻擋紫外線的臭氧層。整個地球生命系的運作就這樣充滿著美麗的生命奇蹟。

  這層紫外線過濾網對地球生命體是非常重要的。就我們所知,火星就是沒有臭氧層,所以它的表層幾乎沒有生命跡象。

  地球就是因為這神奇臭氧層的保護,生命萬物才得以在地表生存。它使所有生命免於受到致命的曬傷,導致白內障,或是皮膚癌,眼部的癌症,以及對免疫系統的傷害。她同時保護了我們生存必須的氧分子,免於被轉成吸入後對生命有害的臭氧。

  臭氧還有另一個神奇的功能,在地表,臭氧是危險的空氣污染物,但是在平流層卻可以阻擋紫外線,使萬物得以生存。

  地球的循環體系就這樣微妙的平衡運作著,直到它負荷過重。而人類的活動持續影響大氣的循環體系,直到超出它原有的負荷,導致臭氧被破壞的速度、遠超過產生的速度。這幾年來,我們已經看到這樣的結果對地表產生的災難性影響。

  全球皮膚癌的發生率都在持續增加中,尤其在臭氧層稀薄的地區。甚至魚群的表皮都因臭氧層的破洞產生病變。

  英國的研究員發現,近年來因為臭氧層破洞而持續增加的紫外線,導致北海地區魚群的表皮受到嚴重的曬傷,甚至起了水泡。尤其是透過皮膚呼吸的幼魚,在牠們可以用鰓呼吸前,所受到的影響最大。英格蘭的普里茅斯海洋研究室指出,「這些幼魚根本沒有抵抗紫外線的能力,因為在人類開始影響大氣層之前,這些小魚從來不需要演化出這樣的特徵。」

  可修復的1998年製造的吉普車Cherokee (圖 威斯康辛州盧森堡SAS) 

  而且我們每天的活動都對大氣層產生巨大的影響。在地球上,每天大約有1800噸的氟氯碳化物,被釋放到大氣層中。這些破壞臭氧層的化學物質來自會漏出冷媒的汽車、家庭冷氣機、冰箱,以及用它當作吹泡劑(blowing agent)的許多工業,例如保麗龍產品的製造工業。正常運作的冷氣機和冰箱並不會釋出這些有害物質。但是請想想看,每天有多少人,把他們的舊車和冰箱送往垃圾場。當他們的冰箱或是車子被摧毀的同時,這些有害的氟氯碳化物就會釋入空氣中。

  這整個情況屬於嚴肅的全球性議題,因此,聯合國環境保護計劃根據保護臭氧層維也納公約(the Vienna Convention for the Protection of the Ozone Layer)、成立了臭氧秘書處(Ozone Secretariat)。以及後來的蒙特婁公約,更進一步規範破壞臭氧層物質的排放量。

  氟氯碳化物層在噴霧髮膠與體香劑裡作為推進劑。為了配合這些國際協定,在美國氟氯碳化物大部份已經被其它物質取代,但是其它的許多產品仍具有害的化學物質。仔細閱讀任何你購買的噴霧性產品上的標籤。

  氟氯碳化物中的氯是破壞臭氧層的元兇。當它擴散到平流層時,就開始破壞珍貴的臭氧分子。此外,被我們釋放到臭氧層的這些有害化學物質,它們破壞臭氧層的速度,比起臭氧層被製造的速度還要快得許多。而沒有人知道實際發生的狀況究竟如何。

  一種致命的殺蟲劑甲基溴,已經被發現是破壞臭氧成的元兇之一。美國的環境保護署已經展開一項清除這些致命化學的計劃。多年來,這些物質一直傷害地表的生物。現在我們發現,這些物質對我們的影響是全球性的。

  對臭氧有害的物質的名單很長,相關規範的成立卻是非常的慢。即便全球的生命體系都已受到威脅,各國政府對於要求工廠更換廠房機組、或是重新設計生產過程,還是猶豫不決。

  國家氣氣象局提供的每日有害紫外線地圖 (圖 國家氣象局)

  當你知道,即使立即停產這些有害的化學物質,它們對臭氧層的影響仍持續50年的事實,那麼這像蝸牛慢步般的規範行動,更會令人抓狂。是的,這些氟氯碳化物的分子需要50年的時間才會抵達臭氧層。

  澳洲,最接近南極臭氧層破洞的國家,具有全世界最高的皮膚癌案例。每三個年紀達到75歲的澳洲人當中,就有兩個人可能會得到皮膚癌。

  澳洲皮膚癌防治協會預計澳洲今年將新增7萬5千個個案,而且3萬人將死於癌症。這樣的結果,大多數來自澳洲每年都增加的超過27萬個皮膚癌病患。

  臭氧層破洞是顯著稀薄的平流層臭氧區。這一現象已經越來越普遍。在北極圈上空已發現一個。但是對於確切的起因以及未來的動向仍所知不多。但是科學家都同意,人類活動必須為這個結果負責。

  不論工廠的損失會有多大,現在都必須立即停產所有導致臭氧層破洞的化學物質。因為地球大氣層的未來就看我們的決定了,這已是沒有商量空間的事實。

  此外,盡量善用你那個老舊的冰箱,如果需要的話,就好好的修理一下。另外,確定你的修車技師是個有信用的人且擁有認證資格,會好好的修理你汽車的冷氣。

  除非我們立刻做一些改變,否則我們的後代子孫將無法無憂無慮的站在陽光下。我和我太太正在期待一個新生命的到來,希望我們的孩子可以盡情享受陽光灑在的臉上的喜悅,而不是恐懼。

資料來源

1. 每日的有害紫外線預測http//www.cpc.ncep.noaa.gov/products/
forecasts/
你可以在國家天氣預報服務站,找到每日的紫外線放射量地圖
http://iwin.nws.noaa.gov/iwin/
iwdspg1.html

2. 進一步了解南極的臭氧層破洞的訊息,請參考http://www.epa.gov/docs/ozone/
science/hole/holehome.html

3. 環境保護署的臭氧層破洞網站
http://www.epa.gov/ozone/

4. 進一步了解導致臭氧層破洞的物質名單http://www.epa.gov/ozone/ods.html

5. 想盡一步了解你可以提供什麼協助
http://www.greenpeace.org/%7Eozone/

6. 進一步了解臭氧層破洞與皮膚癌的關係http://www.ciesin.org/TG/HH/
ozskin1.html

7. 找出你們當地的國會代表,寫信給他們。告訴他們該是強制資源回收的時候了。如果你知道自己的郵遞區號,可以查看
http://www.visi.com/juan/
congress/ziptoit.html
或是查看http//www.webslingerz.com/
jhoffman/congress-email.html

你也可以在此找到你的國會代表http://congress.nw.dc.us/innovate/
index.html

賈基艾倫基理藍儂博士是一位西雅圖的教師兼作家。你可以發現他再思考他的孩子將來到一個怎樣的世界。你可以將你的意見,建議或是對外來的想法寄給他jackie@healingourworld.com或是參觀他的網站http://www.healingourworld.com


By Jackie Alan Giuliano, Ph.D.

Earth, give me back your pure gifts
the towers of silence, which rose
from the solemnity of their roots.
I want to go back to being what I have not been, and learn to go back from such deeps that amongst all natural things
I could live or not live; it does not matter
to be one stone more, the dark stone,
the pure stone which the river bears away.
-- Pablo Neruda, Chilean poet 

We humans have such a hard time believing that our actions can affect anything on a planetary scale. After all, our resources seem limitless. The ocean appears to go on forever, the sky is beautiful, yet out of reach, and when we vacation in a national park, it seems impossible that our one car could be harming all that grandeur. 

But for the last 20 years, evidence has been mounting that we are dramatically affecting a vital attribute of our planet without which, nearly all life would perish. 

The ozone layer seems an unlikely candidate for human impact. Located in the stratosphere of the Earth's atmosphere in a layer from 11 to 16 miles (17 to 26 kilometers) above sea level, the ozone layer keeps about 99 percent of the Sun's harmful ultraviolet radiation (UV) from reaching the Earth's surface.

Southern Hemisphere Ozone Hole on November 16, 2000 (Photo courtesy U.S. National Oceanic and Aeronautics Administration (NOAA)

Stratospheric ozone is produced when oxygen molecules - two atoms of oxygen bonded together - interact with UV from the Sun and with lightning. The UV and lightning rip those atoms apart into their component oxygen molecules. The free roaming oxygen atoms combine with other oxygen molecules to create molecules that are made up of three atoms of oxygen. This is ozone. 

Ozone is constantly being created and destroyed by the very thing that it protects us from - UV. As long as the rate at which ozone is being created and destroyed by UV is fairly constant, then the average concentration of ozone in the atmosphere should be relatively constant. 

Consider the beauty and symmetry of this process for a moment. The UV could destroy all life on the surface, but it is the UV that is responsible for the creation of the ozone that blocks UV! The Earth's life support systems are filled with beautiful miracles such as this.

This UV filter is vital to survival on Earth. Mars has no ozone layer and so its surface is most likely sterilized of all life as we know it.

On Earth, this miraculous layer makes it possible for humans and other life to exist on the surface. It helps protect life from damaging sunburn, cataracts, skin cancer, eye cancer and damage to the immune system. It also prevents the molecular oxygen that we need in the lower atmosphere from being converted to ozone, which is a harmful air pollutant when inhaled. 

Here is another amazing attribute of magical ozone - on the Earth's surface, ozone is a dangerous air pollutant, yet in the stratosphere, it makes life possible by blocking UV. 

The Earth's cycles are delicately balanced and work until they are overloaded. But human activities are overloading the atmospheric cycles, resulting in ozone being destroyed at a rate that is faster than it can be created. We have been seeing the disastrous effects of this on the Earth's surface for a number of years. 

Skin cancer rates have increased worldwide, especially in areas where the ozone layer has thinned. Even fish are experiencing skin problems due to ozone depletion.

British researchers recently discovered that fish in the North Sea are suffering from severe sunburn and blistering of their skin from increased UV because of the thinned ozone layer above that region. The young fish, which breathe through their skin until their gills develop enough, are particularly affected because they don't yet have scales which deflect the UV. The Plymouth Marine Laboratory in England said, "These fish have no protection against the rays because they never needed to evolve one until man began to influence the atmosphere." 

Repairable 1998 Jeep Cherokee (Photo courtesy SAS of Luxemburg, Wisconsin)

And we influence the atmosphere on a grand scale every day. Each day on Earth, over 1,800 tons of chloroflorocarbons (CFC) are released to the atmosphere. These ozone destroying chemicals come from leaking car and home air conditioners, leaking refrigerators, and many industries that use them as a blowing agent such as the styrofoam products industry. Properly functioning air conditioners and refrigerators do not emit these chemicals. But just think of how many people send their old cars and refrigerators each day to the junk yard, where their CFCs will all be released into the air when the cars and fridges are destroyed. 

The situation is of such grave worldwide concern that the United Nations Environment Program has created the Ozone Secretariat for the Vienna Convention for the Protection of the Ozone Layer and later the Montreal Protocol governing the emission of substances that destroy the ozoen layer. 

CFCs used to be found as propellants in hair sprays and deodorants. In accordance with these international agreements, the CFCs have mostly been replaced in the United States, but many products still contain the harmful chemicals. Read the labels carefully on any spray product you buy. 

The chlorine in CFCs is what is destroying the ozone. When it reaches the stratosphere, it breaks up the precious ozone molecules. The amounts of ozone destroying chemicals we are putting into the atmosphere could be destroying ozone at a rate greater than it is being created. No one knows for sure. 

The deadly pesticide methyl bromide has also been found to destroy ozone. The U.S. Environmental Protection Agency has begun a phase out plan for this deadly chemical which has been harming individuals for many years at the Earth's surface. Now we discover that it is harming us on a planetary scale. 

The list of ozone depleting substances is very long and regulatory action is slow at best. Governments are hesitant to do anything that would force industries to retool their plants or redesign their manufacturing processes, even if all life on Earth is at stake

 

Daily UV Hazard Map from the National Weather Service (map courtesy National Weather Service)

The snails pace of regulatory action is particularly maddening when you learn that even if all ozone depleting chemical production stopped today, it would be another 50 years before ozone layer destruction stopped. That's right. It takes about 50 years for a molecule of CFC or other ozone destroying chemical to reach the ozone layer. 

Australia, the country closest to the Antarctic ozone hole, has the highest incidence of skin cancer in the world. Two out of every three Australians living to the age of 75 can expect to develop some type of skin cancer. 

The Australian Cancer Society estimates that this year, more than 75,000 new cases of cancer will be diagnosed in the Australian population and more than 30,000 people will die as a result of cancer. Most of these will be the result of the more than 270,000 cases of skin cancer that develop each year in Australia. 

Ozone holes, areas of significantly decreased concentrations of stratospheric ozone, are becoming increasingly common. One has now been discovered over the Arctic. Little is understood of their origin and movement, but a consensus is growing among scientists that our human activities are responsible. 

The time is now to immediately stop producing all ozone depleting chemicals, regardless of the cost to industry. There should be no discussion since the fate of our planet's atmosphere may hang in the balance. 

And hang on to that old refrigerator as long as you can, and get it fixed if you have to. And be sure your car air conditioner is repaired only by a reputable and authorized mechanic. 

Unless we do something soon, our children may never be able to go outside in the sun without head-to-toe protection. My wife and I have a baby on the way, and we would like to bring our child into a world where the feeling of the Sun on her or his face is a cause for wonder - not fear. 

 
‥網站地圖‥
‥資料檢索‥

結盟授權網站

訂/退閱電子報

 

草山工作假期


回首頁
   

最佳瀏覽環境:IE5.5以上版本,解析度800*600

 
版權皆歸原作者所有,非營利轉載請來信告知!
請支持環境資訊電子報,詳見 捐款方式捐款徵信 
 
社團法人台灣環境資訊協會
Taiwan Environmental Information Association
環境信託基金會(籌) Environmental Trust Foundation
Tel:+886-2-23021122 Fax:+886-2-23020101
108台北市萬華區艋舺大道120巷16弄7號