James Hansen: Why I must speak out about climate change

譯者: 盧 曉天 審譯者: Fuyuan Cheng

What do I know

我到底知道些什麼

that would cause me,

能讓我這個

a reticent, Midwestern scientist,

沉默的中西部科學家

to get myself arrested

在一次白宮的抗議中

in front of the White House protesting?

被逮捕？

And what would you do

如果你知道我所知道的事

if you knew what I know?

你會怎麼做？

Let's start with how I got to this point.

我們就從我如何開始關注這個議題開始吧

I was lucky to grow up

我很慶幸能生長在

at a time when it was not difficult

從輕易從佃農子弟

for the child of a tenant farmer

一路讀到州立大學

to make his way to the state university.

的年代

And I was really lucky

並且很幸運地

to go to the University of Iowa

能在愛荷華大學

where I could study under Professor James Van Allen

詹姆斯．范．艾倫教授門下學習

who built instruments

詹姆斯．范．艾倫教授曾參與

for the first U.S. satellites.

美國第一顆衛星的建造

Professor Van Allen told me

范．艾倫教授曾提過

about observations of Venus,

他對於金星的觀察心得：

that there was intense microwave radiation.

金星有強烈的微波幅射

Did it mean that Venus had an ionosphere?

這代表金星有電離層嗎？

Or was Venus extremely hot?

還是金星氣溫極高呢？

The right answer,

正確答案是

confirmed by the Soviet Venera spacecraft,

金星表面溫度極高

was that Venus was very hot --

正如蘇聯的金星飛行器所證實

900 degrees Fahrenheit.

金星的氣溫高達華氏900度

And it was kept hot

且因一層厚厚的二氧化碳大氣層

by a thick carbon dioxide atmosphere.

使得氣溫居高不下

I was fortunate to join NASA

我很幸運能加入美國太空總署

and successfully propose

並且獲准

an experiment to fly to Venus.

前往金星進行實驗

Our instrument took this image

飛行器拍下了這張

of the veil of Venus,

揭開金星面紗的照片

which turned out to be

這張照片證明了

a smog of sulfuric acid.

金星表層覆蓋著大量硫酸煙霧

But while our instrument was being built,

當衛星還在建造時

I became involved in calculations

我開始思考

of the greenhouse effect

溫室效應

here on Earth,

對地球的影響

because we realized

因為我們意識到

that our atmospheric composition was changing.

大氣成分正在改變

Eventually, I resigned

最後，我辭去了

as principal investigator

金星計畫中

on our Venus experiment

首席研究員的職位

because a planet changing before our eyes

因為眼前地球的變遷

is more interesting and important.

較值得關注也非常重要

Its changes will affect all of humanity.

這些變遷將會影響全人類

The greenhouse effect had been well understood

溫室效應在這個世紀

for more than a century.

早已廣為人知

British physicist John Tyndall,

1850 年，英國物理學家

in the 1850's,

約翰．丁達爾

made laboratory measurements

在實驗室

of the infrared radiation,

做了紅外線輻射的測量

which is heat.

也就是熱的測量

And he showed that gasses such as CO2 absorb heat,

並且表示二氧化碳這類氣體

thus acting like a blanket

會吸收熱能

warming Earth's surface.

就像幫地球蓋上棉被保暖

I worked with other scientists

我和幾位科學家

to analyze Earth climate observations.

共同解析地球氣候的觀察

In 1981,

在 1981 年

we published an article in Science magazine

我們在科學雜誌發表了一篇文章

concluding that observed warming

結論是

of 0.4 degrees Celsius

因為溫室效應二氧化碳的增加

in the prior century

地球每個世紀

was consistent with the greenhouse effect

溫度都會上升

of increasing CO2.

0.4度C

That Earth would likely warm in the 1980's,

地球很有可能是在 1980 年間才開始升溫

and warming would exceed

並且在本世紀末

the noise level of random weather

自然天候所會產生的暖化現象危害程度

by the end of the century.

將會更加劇烈

We also said that the 21st century

我們還認為 21 世紀可能看到

would see shifting climate zones,

氣候區變動、

creation of drought-prone regions

北美和亞洲

in North America and Asia,

易遭旱災地區的形成、

erosion of ice sheets, rising sea levels

冰原侵蝕、海平面上升

and opening of the fabled Northwest Passage.

和西北航道的開通

All of these impacts

所有這些影響

have since either happened

不是已經發生

or are now well under way.

就是正要發生

That paper was reported on the front page of the New York Times

這篇文章上了紐約時報頭版

and led to me testifying to Congress

讓我在 1980 年代

in the 1980's,

向美國國會證實此事

testimony in which I emphasized

公開聲明強調

that global warming increases both extremes

全球暖化會使

of the Earth's water cycle.

地球的水循環更加極端

Heatwaves and droughts on one hand,

一方面，暖化會帶來

directly from the warming,

熱浪和乾旱

but also, because a warmer atmosphere

另一方面

holds more water vapor

越溫暖的大氣層能容納越多

with its latent energy,

帶有潛在能量的水蒸氣

rainfall will become

如此一來

in more extreme events.

降水量會更極端

There will be stronger storms and greater flooding.

暴風雨會更強；洪水也會更猛

Global warming hoopla

全球暖化的紛紛擾擾

became time-consuming

曠日費時

and distracted me from doing science --

也干擾到我的科學研究－

partly because I had complained

多少也是因為我曾抱怨

that the White House altered my testimony.

白宮更改了我的聲明

So I decided to go back

所以我決定回來

to strictly doing science

繼續嚴謹地做科學研究

and leave the communication to others.

把紛擾留給大家

By 15 years later,

15 年後

evidence of global warming was much stronger.

全球暖化的證據更加明確

Most of the things mentioned in our 1981 paper

1981 年發表的文章

were facts.

也大多屬實

I had the privilege to speak twice

我很榮幸能兩次

to the president's climate task force.

和總統的氣候特別小組對話

But energy policies continued to focus

但能源政策卻仍然著眼於

on finding more fossil fuels.

尋找更多化石燃料

By then we had two grandchildren,

那時我有一對孫子

Sophie and Connor.

蘇菲和康納

I decided

我決定

that I did not want them in the future

以後不要讓他們這麼說

to say, "Opa understood what was happening,

「爺爺明知發生什麼事

but he didn't make it clear."

卻不講清楚。」

So I decided to give a public talk

所以我決定發表公開講座

criticizing the lack of an appropriate energy policy.

批評世界欠缺恰當的能源政策

I gave the talk at the University of Iowa in 2004

2004 年，我到愛荷華大學演講

and at the 2005 meeting

另外在 2005 年於

of the American Geophysical Union.

美國地球物理聯盟會議中演講

This led to calls

這幾場演講導致

from the White House to NASA headquarters

白宮致電美國太空總署總部

and I was told that I could not give any talks or speak with the media

並且告知我

without prior explicit approval

若沒有美國太空總署的事先授權

by NASA headquarters.

不得私自對媒體發表任何言論

After I informed the New York Times

在我告知紐約時報此限制後

about these restrictions,

美國太空總署被迫

NASA was forced to end the censorship.

終止這項審查制度

But there were consequences.

然而卻也影響了其他事物

I had been using the first line

我引用了美國太空總署

of the NASA mission statement,

使命聲明的第一條

"To understand and protect the home planet,"

「理解並保護我們賴以生存的行星」

to justify my talks.

替我的發言辯護

Soon the first line of the mission statement

使命聲明第一條隨即就被刪除

was deleted, never to appear again.

未再出現過

Over the next few years

之後幾年裡

I was drawn more and more

正當我以物理學角度

into trying to communicate the urgency

做氣候變遷研究的同時

of a change in energy policies,

我更多次提出

while still researching the physics of climate change.

傳遞能源政策改變的急切

Let me describe the most important conclusion from the physics --

我要提出以物理學為根據的重大結論

first, from Earth's energy balance

不論是從地球能量平衡

and, second, from Earth's climate history.

或是從地球的氣候歷史切入

Adding CO2 to the air

釋出二氧化碳

is like throwing another blanket on the bed.

就像為地球蓋上一層棉被

It reduces Earth's heat radiation to space,

降低了地球熱輻射的散失

so there's a temporary energy imbalance.

造成暫時的能量不平衡

More energy is coming in

地球接受來自太陽的能量（熱能）

than going out,

大於散逸的能量

until Earth warms up enough

直到地球達到足夠的溫度

to again radiate to space

便會再次釋出能量

as much energy as it absorbs from the Sun.

至太空

So the key quantity

所以可以驗證地球能量不平衡

is Earth's energy imbalance.

的關鍵數據

Is there more energy coming in

在於地球所接受的能量

than going out?

有比釋出的能量大嗎？

If so, more warming is in the pipeline.

若答案為是，代表暖化正在發生

It will occur without adding any more greenhouse gasses.

而且不需更多溫室氣體就會發生了

Now finally,

現在

we can measure Earth's energy imbalance precisely

我們終於可以

by measuring the heat content

藉由測量地球熱能的儲存量

in Earth's heat reservoirs.

精準的算出地球能量的不平衡

The biggest reservoir, the ocean, was the least well measured,

我們利用超過三千多個散佈世界各大洋

until more than 3,000 Argo floats

的海洋觀測網浮標（Argo float）

were distributed around the world's ocean.

對世界最大的水庫－海洋－進行測量

These floats reveal

浮標回傳的資料顯示

that the upper half of the ocean

淺海區的溫度

is gaining heat at a substantial rate.

正急速上升

The deep ocean is also gaining heat at a smaller rate,

深海區的溫度也緩緩上升

and energy is going

而且過剩的能量即將影響到

into the net melting of ice all around the planet.

地球周邊冰層的淨融化速度

And the land, to depths of tens of meters,

甚至連數十米深度的土地

is also warming.

也正在暖化中

The total energy imbalance now

現在能源不平衡的總量

is about six-tenths of a watt per square meter.

已達到每平方公尺 0.6 瓦

That may not sound like much,

乍聽之下也許不多

but when added up over the whole world, it's enormous.

但若把全世界加總，數字會很龐大

It's about 20 times greater

大約是

than the rate of energy use by all of humanity.

全人類能源使用量的 20 倍

It's equivalent to exploding

這相當於每年有 365 天

400,000 Hiroshima atomic bombs per day

每天引爆 40 萬顆

365 days per year.

廣島原子彈

That's how much extra energy

那也就是

Earth is gaining each day.

地球每天過剩的能量

This imbalance,

若是我們

if we want to stabilize climate,

想穩定這種不平衡的氣候

means that we must reduce CO2

我們就必須減少二氧化碳的排放

from 391 ppm, parts per million,

從每百萬 391 ppm

back to 350 ppm.

降到 350 ppm

That is the change needed to restore energy balance

那是使能量恢復平衡

and prevent further warming.

和阻止氣候上升的必要改變

Climate change deniers argue

否認氣候變遷的人主張

that the Sun is the main cause of climate change.

太陽才是氣候變遷的主因

But the measured energy imbalance occurred

但是這次能量失衡的測量

during the deepest solar minimum in the record,

是在有記錄以來太陽極深處能量的最小值時進行

when the Sun's energy reaching Earth was least.

當時太陽的能量傳遞到地球是最小的

Yet, there was more energy coming in than going out.

但到目前為止，能量輸入仍大於輸出

This shows that the effect of the Sun's variations on climate

表示太陽偏移對氣候的影響

is overwhelmed by the increasing greenhouse gasses,

遠不如因為燃燒化石燃料

mainly from burning fossil fuels.

所產生二氧化碳所帶來的影響

Now consider Earth's climate history.

現在思考一下地球的氣候歷史

These curves for global temperature,

這幾個包括世界氣溫

atmospheric CO2 and sea level

大氣中二氧化碳和海平面的曲線

were derived from ocean cores and Antarctic ice cores,

是從海洋內核和南極冰河推導出

from ocean sediments and snowflakes

從海洋的沉積物

that piled up year after year

和超過 80 萬年

over 800,000 years

年復一年所累積的雪

forming a two-mile thick ice sheet.

以致形成一個兩英哩厚的冰原

As you see, there's a high correlation

正如你看到的

between temperature, CO2 and sea level.

氣溫、二氧化碳和海平面緊密相關

Careful examination shows

嚴謹的調查顯示

that the temperature changes

幾個世紀以來

slightly lead the CO2 changes

氣溫的改變

by a few centuries.

微幅的造成二氧化碳改變

Climate change deniers like to use this fact

否認氣候變遷的人喜歡用這個事實

to confuse and trick the public

來混淆欺騙大眾

by saying, "Look, the temperature causes CO2 to change,

說：「是氣溫造成二氧化碳量增加

not vice versa."

反之則不成立。」

But that lag

但溫度變化幅度高於二氧化碳變化幅度

is exactly what is expected.

正如同我們所預期的情況

Small changes in Earth's orbit

地球軌道

that occur over tens to hundreds of thousands of years

數十萬年的偏移

alter the distribution

改變了

of sunlight on Earth.

地球受光照的分配量

When there is more sunlight

當高緯度的夏天

at high latitudes in summer, ice sheets melt.

日照長時，冰原開始融化

Shrinking ice sheets

縮小的冰原

make the planet darker,

使地球外表更昏暗

so it absorbs more sunlight

吸收更多日光後

and becomes warmer.

進而升溫

A warmer ocean releases CO2,

升溫中的海洋會釋出二氧化碳

just as a warm Coca-Cola does.

就像一瓶熱的可口可樂一樣

And more CO2 causes more warming.

二氧化碳越多，暖化越快

So CO2, methane, and ice sheets

所以二氧化碳、甲烷和冰原

were feedbacks

擴大了

that amplified global temperature change

全球氣溫的變化

causing these ancient climate oscillations to be huge,

儘管氣候變遷被一個非常微弱的力量

even though the climate change was initiated

所啟動

by a very weak forcing.

最終導致這些遠古氣候產生巨大變革

The important point

重要的是

is that these same amplifying feedbacks

這些同樣擴大中的環境反撲

will occur today.

現在就會發生

The physics does not change.

根據物理學定律

As Earth warms,

現在因為排放過多二氧化碳

now because of extra CO2 we put in the atmosphere,

所以隨著地球逐漸暖化

ice will melt,

冰會融化

and CO2 and methane will be released

逐漸加溫的海洋則會釋出

by warming ocean and melting permafrost.

更多二氧化碳和甲烷

While we can't say exactly how fast

雖然我們不知道

these amplifying feedbacks will occur,

這些擴大中的環境反撲什麼時候會發生

it is certain they will occur,

但可以確定的是它一定會發生

unless we stop the warming.

除非我們停止暖化

There is evidence

已經有證據顯示

that feedbacks are already beginning.

環境反撲正要開始

Precise measurements

藉由重力觀測衛星－GRACE

by GRACE, the gravity satellite,

精密的測量

reveal that both Greenland and Antarctica

顯示出格陵蘭島與南極大陸

are now losing mass,

正大量流失

several hundred cubic kilometers per year.

每年流失數百平方公里的冰原

And the rate has accelerated

並且較 9 年前

since the measurements began

開始測量時

nine years ago.

流失的速率不斷加快

Methane is also beginning

甲烷也開始

to escape from the permafrost.

從永凍土被釋出

What sea level rise

海平面上升

can we look forward to?

會到什麼程度呢？

The last time CO2 was 390 ppm,

最後一次測得的二氧化碳值為 390ppm

today's value,

也就是今天進行測量的

sea level was higher

海平面已高出

by at least 15 meters, 50 feet.

至少 15 公尺（約 50 英呎）

Where you are sitting now

你們現在坐的地方

would be under water.

很可能會被海淹沒

Most estimates are that, this century,

大多數的預測是

we will get at least one meter.

海平面將在世紀末上升一公尺

I think it will be more

我敢說

if we keep burning fossil fuels,

如果我們繼續燃燒化石燃料

perhaps even five meters, which is 18 feet,

在不久之後，甚至可能升高 5 公尺

this century or shortly thereafter.

也就是 18 英呎

The important point

重點是

is that we will have started a process

人們已經開始了一個

that is out of humanity's control.

超出人類控制的過程

Ice sheets would continue to disintegrate for centuries.

冰原每個世紀持續崩解

There would be no stable shoreline.

穩定的海岸線也不復在

The economic consequences are almost unthinkable.

對經濟的影響更是無法想像

Hundreds of New Orleans-like devastations

世界各地將遭受

around the world.

紐奧良風災般的破壞

What may be more reprehensible,

更應受指責的是

if climate denial continues,

在人們持續否認氣候變遷下

is extermination of species.

物種不斷地滅絕

The monarch butterfly

如果我們不改變使用化石燃料的習慣

could be one of the 20 to 50 percent of all species

叢斑蝶可能是

that the Intergovernmental Panel on Climate Change estimates

政府機構預測

will be ticketed for extinction

在本世紀末

by the end of the century

將瀕臨絕種的 25% 至 50% 物種

if we stay on business-as-usual fossil fuel use.

的其中之一

Global warming is already affecting people.

全球暖化確實已深深影響著人們

The Texas, Oklahoma, Mexico

去年在德州、奧克拉荷馬

heatwave and drought last year,

和墨西哥發生的熱浪和乾旱

Moscow the year before

前年的莫斯科

and Europe in 2003,

還有 2003 年的歐陸

were all exceptional events,

都發生異常的氣候現象

more than three standard deviations outside the norm.

氣候觀測值都超出三個標準差以上

Fifty years ago,

50 年前

such anomalies

這種異常現象

covered only two- to three-tenths

僅影響 0.2% 至 0.3%

of one percent of the land area.

的土地面積

In recent years,

但近年來

because of global warming,

因為全球暖化

they now cover about 10 percent --

影響面積已達 10%

an increase by a factor of 25 to 50.

有 25 到 50 倍的增長幅度

So we can say with a high degree of confidence

所以我們可以自信的說

that the severe Texas and Moscow heatwaves

德州和莫斯科嚴重的熱浪

were not natural;

並非自然現象

they were caused by global warming.

而是全球暖化的產物

An important impact,

如果

if global warming continues,

我們讓全球暖化持續發生

will be on the breadbasket of our nation and the world,

帶來的影響

the Midwest and Great Plains,

將包括中西部及大平原

which are expected to become prone to extreme droughts,

預計在幾十年後都將面臨

worse than the Dust Bowl,

比沙塵暴更糟糕的

within just a few decades,

極端乾旱

if we let global warming continue.

所以我們應該避免全球暖化

How did I get dragged deeper and deeper

為何我要一再深入這個議題

into an attempt to communicate,

並且試圖與多數人溝通

giving talks in 10 countries, getting arrested,

我曾到 10 個國家演講、曾被逮捕

burning up the vacation time

浪費無數假期

that I had accumulated over 30 years?

試圖傳遞我鑽研了 30 年的議題

More grandchildren helped me along.

許多後輩也參與協助我

Jake is a super-positive,

傑克是個積極上進

enthusiastic boy.

又富熱情的男孩

Here at age two and a half years,

才兩歲半的他

he thinks he can protect

就自認能保護

his two and a half-day-old little sister.

剛滿兩歲的妹妹

It would be immoral

把當前

to leave these young people

無法掌控的氣候系統

with a climate system

留給年輕的下一代

spiraling out of control.

是不道德的

Now the tragedy about climate change

現在

is that we can solve it

我們可以用一項

with a simple, honest approach

簡單又公平的方法

of a gradually rising carbon fee

來解決氣候變遷

collected from fossil fuel companies

所造成的悲劇

and distributed 100 percent electronically

就是逐漸提高向不可再生能源公司徵收的碳費

every month to all legal residents

並以電子型式

on a per capita basis,

平均分配給每一位合法公民

with the government not keeping one dime.

政府一毛不取

Most people would get more in the monthly dividend

這樣大多數人拿到的每月分紅

than they'd pay in increased prices.

會比他們所付的碳費高出許多

This fee and dividend

這項收費和紅利制度

would stimulate the economy

會刺激經濟

and innovations,

並帶動改革

creating millions of jobs.

創造無數職缺

It is the principal requirement

這些主要規則

for moving us rapidly

能帶領我們快速迎向

to a clean energy future.

一個擁有乾淨能源的未來

Several top economists

這是由幾位經濟學者

are coauthors on this proposition.

所共同擬定的建議

Jim DiPeso of Republicans for Environmental Protection

共和黨員環境保護協會的吉姆．帝帕索

describes it thusly:

正是如此形容：

"Transparent. Market-based.

「透明度和市場經濟

Does not enlarge government.

都不會擴大政府機能

Leaves energy decisions to individual choices.

把能源決定權交還給公民

Sounds like a conservative climate plan."

聽起來是個穩當的氣候計畫。」

But instead of placing a rising fee on carbon emissions

我們的政府強迫全世界大眾

to make fossil fuels pay

每年資助

their true cost to society,

4 到 5 千億美元

our governments are forcing the public

而非

to subsidize fossil fuels

提高碳費

by 400 to 500 billion dollars

讓化石燃料付出

per year worldwide,

造成社會傷害的真正代價

thus encouraging extraction of every fossil fuel --

因此鼓勵榨乾化石燃料－

mountaintop removal,

山頂的剷除

longwall mining, fracking,

長壁採礦、水力壓裂法

tar sands, tar shale,

瀝青沙、瀝青頁岩

deep ocean Arctic drilling.

和北極圈深海鑽油

This path, if continued,

若持續如此

guarantees that we will pass tipping points

能保證會超越臨界點

leading to ice sheet disintegration

導致冰原崩解

that will accelerate out of control of future generations.

使後代更無法掌握

A large fraction of species

大部分的物種

will be committed to extinction.

將會絕種

And increasing intensity of droughts and floods

更加強烈的乾旱和水災

will severely impact breadbaskets of the world,

將會嚴重影響世界的產糧區

causing massive famines

造成大規模饑荒

and economic decline.

和經濟衰退

Imagine a giant asteroid

想像一下，一顆巨大的小行星

on a direct collision course with Earth.

正與地球同在導致相撞的軌道

That is the equivalent

這就是

of what we face now.

我們現在所面臨的狀況

Yet, we dither,

然而我們卻驚慌失措

taking no action

沒有採取

to divert the asteroid,

扭轉情勢的行動

even though the longer we wait,

即便我們知道

the more difficult and expensive it becomes.

拖越久難度和花費越高

If we had started in 2005,

如果我們 2005 年就開始

it would have required emission reductions of three percent per year

我們每年必須降低 3% 的排放量

to restore planetary energy balance

使地球恢復能量平衡

and stabilize climate this century.

並且穩定本世紀的氣候

If we start next year,

如果我們明年開始

it is six percent per year.

每年降幅就必須提升到 6%

If we wait 10 years, it is 15 percent per year --

要是在等 10 年，降幅更提升到 15%

extremely difficult and expensive,

難度極大且需付出龐大代價

perhaps impossible.

不如說是天方夜譚

But we aren't even starting.

但我們根本還沒開始

So now you know what I know

如今你已經知道一切

that is moving me to sound this alarm.

讓我極力想喚起警覺的資訊

Clearly, I haven't gotten this message across.

無疑地，我還沒完成訊息傳遞

The science is clear.

科學已經很清楚

I need your help

我需要你們

to communicate the gravity and the urgency

協助傳遞

of this situation

當前處境的嚴重和急切性

and its solutions

和有效的

more effectively.

解決之道

We owe it to our children and grandchildren.

這是我們應該對晚輩做的

Thank you.

謝謝

(Applause)

（掌聲）