Whatever happened to the hole in the ozone layer? - Stephanie Honchell Smith

Translator: karina ip Reviewer: Thomas Tam

In the 1980s, the world faced a huge problem:

喺 80 年代，全球面對 一個好嚴重嘅問題：

there was a rapidly expanding hole in the ozone layer.

喺臭氧層有個迅速增大嘅窿。

So, what happened? And is it still there?

究竟發生咗啲咩？ 佢仲喺唔喺度呢？

Let’s go back to the beginning.

返去事件嘅開頭。

The Sun makes life on Earth possible,

太陽使地球可能擁有生命，

but too much exposure to its UV radiation damages plant and animal DNA.

但係暴曬，UV 輻射 會傷害植物同動物嘅 DNA。

Thankfully, about 98% of that radiation is absorbed by ozone molecules

幸好，約 98% 嘅 UV 畀分布喺平流層嘅臭氧分子吸收，

dispersed in the stratosphere,

which are continuously broken apart and reformed in this process,

而喺呢個過程中 佢哋持續噉分裂又重組，

maintaining a delicate equilibrium.

保持住一個脆弱嘅平衡點。

But in the early 1970s, two chemists— Mario Molina and Sherwood Rowland—

喺 70 年代初，兩位化學家 Mario Molina 同 Sherwood Rowland，

demonstrated that widely used chemicals called chlorofluorocarbons, or CFCs,

指出一種常用嘅化學物質， 「氯氟烴」、或者 CFC，

could upset this balance.

會導致失去平衡。

CFCs were developed in the 1920s by three US-based corporations

CFC 喺 1920 年代 由三間美國嘅集團開始生產，

as coolants for refrigerators.

作為雪櫃嘅冷凍劑。

唔同當時其他嘅冷凍劑選擇， 例如阿摩尼亞或者二氯甲烷，

Unlike existing alternatives— such as ammonia or methyl chloride—

CFCs were non-flammable and non-toxic—

CFC 係唔會助燃 同埋冇毒嘅，

meaning they wouldn't burst into flames or cause deadly gas leaks.

即係佢哋唔會着火 或者引起致命嘅氣體洩漏。

They also made great propellants, foaming agents, and fire-retardants.

佢哋亦都可以做推進劑， 發泡劑同阻燃劑。

CFCs soon found their way into a variety of everyday items

CFC 好快就滲入咗 喺日常生活用品裏面，

and became a multi-billion dollar per year industry.

而成為咗每年 幾十億美金嘅行業。

In the lower atmosphere, CFCs don’t break down or react with other molecules.

喺低層大氣度，CFC 唔會分解， 亦都唔會同其他分子有反應。

But Molina and Rowland showed that in the stratosphere,

但 Molina 同 Rowland 指出喺平流層入面，

they're broken apart by UV light, releasing chlorine atoms.

CFC 會比 UV 分解， 釋放氯原子。

氯原子其後同臭氧反應，

These then react with ozone,

destroying it faster than it can be replenished.

破壞比修復嘅速度快。

A single chlorine atom can destroy thousands of ozone molecules

一粒氯原子可以破壞 上千粒臭氧分子，

before finally reacting with something else and forming a stable molecule.

最後再同其他物質反應， 成為一個穩定嘅分子。

Seeing the threat to their bottom line,

當威脅到商業利益，

CFC producers pushed back to discredit the scientists,

CFC 嘅製造商反擊， 抹黑嗰啲科學家，

even accusing them of working for the KGB.

甚至指控佢哋幫 KGB 做嘢。

Initial estimates showed that within 60 years,

初步估計指出喺 60 年內，

CFCs could reduce ozone concentrations by 7%.

CFC 可以令臭氧濃度降低 7%。

But by 1985, it became clear that ozone depletion, especially over Antarctica,

但係到 1985 年， 尤其喺南極洲上空，

臭氧嘅消耗正在加速。

was happening much faster.

Here, the extremely cold temperatures and unique structure of Antarctic clouds

呢度極端嘅寒冷 同南極雲嘅獨特結構，

accelerated ozone loss.

令臭氧流失速度加快。

Scientists stationed in Antarctica noticed a massive drop

喺南極洲駐守嘅科學家 留意到春天

in overhead ozone occurring every spring.

頭頂上嘅臭氧 都會大幅降低。

Satellite data revealed the vast extent of these losses

衛星數據顯示 很大程度上呢啲流失，

and chemical tests confirmed that the cause was unquestionably CFCs.

同化學驗證都顯示 起因毫無疑問係 CFC 造成。

NASA soon released visualizations, which were broadcast around the world

NASA 不久後發布圖像， 傳播全世界，

and captured public attention.

吸引咗大眾嘅注意。

If ozone depletion continued, rates of skin cancer would skyrocket.

如果臭氧繼續流失， 皮膚癌嘅發病率將會飆升。

Photosynthesis would be impaired, making plants—

光合作用亦都會受到影響，

令植物：稻米、小麥、粟米

including rice, wheat, and corn—

less productive and more susceptible to disease.

生長速度減慢，更加容易生病。

Global agricultural production would plummet,

全球嘅農業生產總值會急跌，

and entire ecosystems would collapse.

而整個生態環境會崩潰。

But many politicians— weighing immediate economic concerns over long-term ones—

但係好多政治人物重視嘅係 即時經濟問題，長遠嘅就唔會理。

disagreed about what to do.

仲反對要做任何嘢。

The fight to ban CFCs found two unlikely allies

爭取禁用 CFC 出現兩個唔尋常嘅盟友，

in US President Ronald Reagan and UK Prime Minister Margaret Thatcher.

美國總統 Ronald Reagan 同英國首相 Margaret Thatcher。

Despite their general opposition to government regulation,

儘管佢哋通常 反對政府嘅監管，

Reagan, who had undergone treatment for skin cancer,

Reagan 因為受過皮膚癌治療，

and Thatcher, who was trained as a chemist,

同 Thatcher 受過化學家訓練，

recognized the need for immediate action.

認識到需要立即採取行動。

The US and UK, along with Canada, Norway, Sweden, and Finland,

美國同英國，聯同加拿大、 挪威、瑞典、芬蘭，

led calls for an international ban on CFCs.

率先呼籲國際禁止使用 CFC。

In 1987, representatives signed the Montreal Protocol,

1987 年，各國代表 簽咗蒙特利爾議定書，

requiring the rapid phasing out of CFCs

要求快速淘汰使用 CFC

and creating a fund to assist Global South countries

以及成立基金 協助全球南方嘅國家

in obtaining affordable, non-ozone depleting alternatives.

去獲取能夠負擔、 唔使消耗臭氧嘅替代品。

It was later ratified by every country on Earth—

後來所有國家都通過——

the only treaty in history to achieve this.

歷史上只係得 呢個公約能夠做到。

In 1995, Molina, Rowland, and their Dutch colleague Paul Crutzen,

喺 1995 年，Molina, Rowland 同荷蘭籍嘅 Paul Crutzen，

were jointly awarded the Nobel Prize in Chemistry.

一齊獲得諾貝爾化學獎。

As the use of CFCs declined,

當減少使用 CFC，

the ozone hole began shrinking,

臭氧層個窿開始縮細，

and is predicted to disappear entirely by 2070.

而預計 2070 年會完全消失。

But we’re not out of the woods yet.

但仲未脫離危險。

While the ban was a win for the climate, as CFCs are potent greenhouse gases,

由於 CFC 係強效溫室氣體， 禁止使用係氣候嘅勝利，

the alternatives that replaced them— hydrofluorocarbons, or HFCs— are too.

取而代之嘅氫氟烴（HFC） 亦都係類似嘅物質。

While generally less potent than CFCs,

HFC 雖然通常比 CFC 冇咁強，

HFCs still trap more heat than carbon dioxide

相比二氧化碳 保留住更多嘅熱能，

and are contributing to climate change.

仍然影響著氣候變化。

To address this, in 2016, the Kigali Amendment

喺 2016 年就呢件事 達成咗基加利修正案，

was added to the Montreal Protocol,

附加到蒙特利爾議定書，

calling for an 85% cut in global HFCs by 2047.

要求要到 2047 年 全球 HFC 用量減少 85%。

This alone could avoid up to 0.5°C of global warming by the end of the century.

呢個修正案直至世紀末， 阻止全球 0.5°C 暖化效應。

Today, as we face the existential threat of climate change,

現今氣候變化 構成我哋嘅生存威脅，

the Montreal Protocol serves as a model for the decisive global cooperation

蒙特利爾議定書 可以作為世界合作決斷嘅典範，

we need to combat it.

我哋要為此而奮鬥。

The question is, what will it take for us to come together again?

問題係，我哋點樣 先可以再次團結一致呢？