Whatever happened to acid rain? - Joseph Goffman

譯者: Regina Chu 審譯者: Yi-Ping Cho (Marssi)

In 1963, scientists studying Hubbard Brook Experimental Forest in New Hampshire

1963 年，在新罕布夏州 研究哈伯德溪實驗林的科學家

made a shocking discovery.

有了驚人的發現

Their most recent rainfall samples were nearly 100 times more acidic than usual.

他們最近一次的降雨樣本酸度 比往常的高將近一百倍

At these levels, additional downpours of acid rain

照這樣下去，未來數十年內的傾盆酸雨

would destroy the region’s marine and arboreal ecosystems

就會毀掉這個地區的海洋及樹棲生態系

in a matter of decades.

只要數十年！

Urgently sharing their findings with fellow researchers,

他們急切地將發現告訴其他的研究人員

they were determined to answer two questions:

並決意要找出兩個問題的答案：

what was causing this deadly rainfall? And what could be done to stop it?

這種致命酸雨的起因是什麼？ 怎麼做才能終止這種現象？

Rain is never just composed of water.

雨水並非只有水

Chemicals and particulates in the atmosphere can be found in every drop,

大氣中的化學物質及各種微粒 都可在每滴雨水中發現

and some compounds— like carbon dioxide—

某些化合物──像二氧化碳──

make even regular rainfall slightly acidic.

會使正常的降雨微酸

But this pales in comparison to the powerful acids produced

但這個酸的程度根本比不上

水和氮氧化物或二氧化硫作用時 產生的強酸

when water interacts with oxides of nitrogen or sulfur dioxide.

On the pH scale which measures acidity,

測量酸度的 pH 值

each whole number is 10 times more acidic than the one above it.

每一個整數都比上一個數字酸十倍

And where normal rain has a pH of roughly 5.4,

正常雨水的酸鹼值約為 5.4

rain that’s interacted with these gases can rank as low as 3.7.

跟這些氣體作用的雨水可以低到 3.7

Oxides of nitrogen and sulfur dioxide can appear naturally

氮氧化物及二氧化硫可自然生成

as a short-lived byproduct of volcanic eruptions or lightning strikes.

為火山爆發或閃電雷擊時的短暫副產物

But power plants, refineries, and vehicles that use fossil fuels

但是發電廠、煉油廠 及使用石化燃料的汽車

consistently pump large quantities into the air.

持續不斷地將其大量排放入空氣中

These dangerous gases travel with the wind

這些有害的氣體隨風移動

spreading hundreds of kilometers from the pollution’s source.

從汙染源頭散播至數百公里遠

Acting like roaming clouds of destruction,

就像四處飄蕩的摧毀之雲

their presence dramatically increases the acidity of local precipitation,

它們的存在會大幅增加 所在地雨水的酸度

creating acid rain, acid snow, and acid fog.

形成酸雨、酸雪及酸霧

These all acidify lakes and streams, kill crops and forests,

被酸化的湖泊及溪流會扼殺作物及森林

and damage soil to inhibit future growth.

破壞土壤，抑制未來的生長

Over time, acid rain can even corrode human structures made of stone or metal.

時間久了，酸雨還會侵蝕 人類以石頭或金屬造的建築物

By the 1970s, scientists in North America and Europe classified acid rain

到了 1970 年，北美及歐洲的科學家

將酸雨歸類為重大環境威脅

as a major environmental threat.

But despite clear evidence tying the problem to air pollution,

儘管有明確證據顯示 這個問題與空污有關

companies denied responsibility and cast doubt on the research.

企業不但卸責還對研究提出質疑

In the United States, corporations lobbied against regulating pollution,

在美國，企業遊說反對污染管理法規

and convinced politicians that such policies

並說服政客，說此類政策

would raise energy costs and threaten jobs.

會提高能源費用並造成失業

These obstacles led the government to delay changes,

這些阻礙使政府推遲變革

and mandate further research into the issue.

並要求進一步研究此問題

But after a decade of mounting concern, Congress finally took action.

但是在十年的強烈關注後 國會終於做出行動

Since the bulk of sulfur dioxide emissions came from power plants,

因為大部分的二氧化硫都由發電廠排出

the government set a limit on the total amount of it

政府就設下電力部門

the electric power sector could emit each year.

每年可以排放的總量限制

Then, they divided the permitted emissions into a fixed number of “allowances”

然後，他們將許可的排放量 分成固定的額度

distributed to each power plant.

分配給每個發電廠

A plant could then choose to emit as much sulfur dioxide as they were allowed,

各個發電廠可以決定 要排出額度上限的二氧化硫

or reduce their emissions and sell their unused allowances to other power plants.

或是減少排放量 將沒用完的額度賣給其他發電廠

This system, known as “cap and trade,”

這個系統稱為總量管制與交易

offered power plants the economic flexibility to keep costs low

讓發電廠擁有經濟上的彈性 以維持低成本

while strictly limiting pollution.

同時還能嚴格限制污染

Many critics called these allowances licenses to pollute,

批評者認為這種額度是污染執照

or said the government was selling clean air.

或說政府在賣乾淨的空氣

But since the cap was set to lower five years into the program,

但是自從總量限制開始實施五年後

it forced every utility company to reduce emissions in the long term.

每個發電廠都被迫減低長期排放量

Some plants added desulfurizing scrubbers to their smokestacks,

有些發電廠在煙囪上加裝脫硫洗滌器

or switched to low-sulfur coal and natural gas.

或改用低硫煤炭及天然氣

Oxides of nitrogen emissions were also reduced

氮氧化物排放量

with relatively low-cost technologies.

也因使用相對低成本的技術而減少

These advances allowed the power sector to grow

這些進展讓電力部門成長

while the cap kept pollution under control.

同時，總量額度使污染受到控制

By 1985, Canada and the European Union adopted their own solutions,

到 1985 年，加拿大及歐盟 採用了自己的解決方案

and international treaties began circulating

國際條約開始流通

to reduce air pollution worldwide.

以減少全球的空氣污染

Today, this science-driven economic policy has largely eliminated acid rain

今天，這項由科學驅動的經濟政策

已大幅消除美國及加拿大的酸雨

across the United States and Canada.

And while many ecosystems still need time to recover,

即使許多生態系仍需要時間復原

scientists have sped up the restoration of other areas

科學家已加速其他地方的復育

by reintroducing essential organisms killed off by acid rain.

重新引進被酸雨殺光的主要生物

Some countries, like Russia, India, and China

俄國、印度及中國等國家

still rely heavily on high-sulfur coal

仍然重度仰賴高硫煤炭

and continue to struggle with the environmental consequences.

並繼續死挨活撐其環境後果

However, acid rain’s relatively quick journey from major threat to minor issue

然而，酸雨能相對快速地 從主要威脅變成次要威脅

is rightly celebrated as a victory for policies that protect the environment.

是可以正大光明慶祝的 環保政策大勝利

Cap and trade can’t solve every environmental problem.

總量與交易不能解決每一個環境問題

But by using scientific consensus to guide policy,

但是，以科學共識引導政策

adopting efficient technology,

採用高效技術

and being unafraid to impose reasonable costs for pollution,

並無畏徵收合理的污染成本

countries can stop a growing storm of destruction before it’s too late.

各國可以及時阻止日益嚴重的毀滅風暴