Rob Dunbar: The threat of ocean acidification

104,985 views ・ 2010-09-13

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譯者: kane tan 審譯者: Harvey Hao Liu
00:15
If you really want to understand
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如果你真的想了解
00:18
the problem that we're facing with the oceans,
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我們目前所面對的海洋問題,
00:21
you have to think about the biology
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那麼在你思考生物學時
00:23
at the same time you think about the physics.
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也必須同時思考物理學。
00:26
We can't solve the problems
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除非我們能夠以跨領域的方式
00:28
unless we start studying the ocean
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來對海洋進行研究,
00:30
in a very much more interdisciplinary way.
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否則我們不可能解決這些問題。
00:33
So I'm going to demonstrate that through
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所以我將會藉由討論海洋面臨的一些氣候變遷
00:35
discussion of some of the climate change things that are going on in the ocean.
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來證明這些問題。
00:38
We'll look at sea level rise.
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我們會討論海面上升。
00:40
We'll look at ocean warming.
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以及海洋暖化現象。
00:42
And then the last thing on the list there, ocean acidification --
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然後是最後一個問題,海洋酸化現象 --
00:45
if you were to ask me, you know, "What do you worry about the most?
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如果你問我,"你最擔心的事情是什麼?
00:48
What frightens you?"
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什麼會令你恐懼?"
00:50
for me, it's ocean acidification.
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對我來說,那就是海洋酸化。
00:52
And this has come onto the stage pretty recently.
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這是最近剛浮上檯面的問題。
00:54
So I will spend a little time at the end.
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所以我會在最後花一點時間來討論它。
00:57
I was in Copenhagen in December
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在10月的時候,我參加了哥本哈根會議,
00:59
like a number of you in this room.
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如同在座部份人一樣。
01:01
And I think we all found it, simultaneously,
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我想我們都同時發現,
01:04
an eye-opening
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一個令人大開眼界
01:06
and a very frustrating experience.
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卻也令人沮喪的經驗。
01:08
I sat in this large negotiation hall,
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我坐在巨大的協商會議廳裡,
01:11
at one point, for three or four hours,
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在同一個位子上三~四個小時,
01:13
without hearing the word "oceans" one time.
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完全沒有聽見"海洋"這個字。
01:17
It really wasn't on the radar screen.
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它確實沒有被列入議題。
01:20
The nations that brought it up
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當各國領袖開始發言時,
01:22
when we had the speeches of the national leaders --
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它才被人提到 --
01:24
it tended to be the leaders of the small island states,
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但卻都只是一些小型島國的領袖,
01:27
the low-lying island states.
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一些地勢低窪的島國。
01:29
And by this weird quirk
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而由於這個詭異的
01:31
of alphabetical order of the nations,
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國名排列方式,
01:34
a lot of the low-lying states,
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許多地勢低窪的國家
01:36
like Kiribati and Nauru,
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例如吉里巴斯共和國以及諾魯共和國,
01:38
they were seated at the very end of these immensely long rows.
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他們都坐在這些長排座位的最尾端。
01:41
You know, they were marginalized
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你知道的,他們在這間會議廳中
01:43
in the negotiation room.
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被邊緣化了。
01:45
One of the problems
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其中一項問題
01:47
is coming up with the right target.
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是要找出一個正確的目標。
01:49
It's not clear what the target should be.
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他們並不清楚目標是什麼。
01:51
And how can you figure out how to fix something
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那麼你又怎麼可能在目標不明確時,
01:53
if you don't have a clear target?
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找出解決問題的辦法呢?
01:55
Now, you've heard about "two degrees":
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大家都聽過 "二度" 吧,
01:57
that we should limit temperature rise to no more than two degrees.
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我們應該避免溫度上升超過二度。
02:00
But there's not a lot of science behind that number.
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但這數字背後並沒有什麼科學根據。
02:03
We've also talked about
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我們還討論了
02:05
concentrations of carbon dioxide in the atmosphere.
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大氣層中二氧化碳的濃度。
02:07
Should it be 450? Should it be 400?
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它應該被設在450? 還是400呢?
02:10
There's not a lot of science behind that one either.
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這些數字同樣也沒有什麼科學根據。
02:13
Most of the science that is behind these numbers,
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這些數字背後大部分的科學根據,
02:15
these potential targets,
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這些重要的目標,
02:17
is based on studies on land.
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都是依據在陸地上進行的研究。
02:19
And I would say, for the people that work in the ocean
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而我想說的是,對於那些研究海洋
02:22
and think about what the targets should be,
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以及思考該設定哪些目標的人來說,
02:24
we would argue that they must be much lower.
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我們都認為它們應該要更低才對。
02:26
You know, from an oceanic perspective,
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你知道嗎,對於海洋生態而言,
02:28
450 is way too high.
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450 實在太高了。
02:30
Now there's compelling evidence
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目前已經有強力的證據
02:32
that it really needs to be 350.
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來說明那必須設定在 350。
02:34
We are, right now, at 390 parts per million
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現在大氣中的二氧化碳濃度
02:37
of CO2 in the atmosphere.
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是 百萬分之390。
02:39
We're not going to put the brakes on in time to stop at 450,
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我們不可能在450的時候才踩煞車,
02:42
so we've got to accept we're going to do an overshoot,
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所以我們必須接受去設定一個嚴苛的標準,
02:45
and the discussion as we go forward
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而在我們接下來的討論中,
02:47
has to focus on how far the overshoot goes
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必須專注於這個嚴苛的標準要進行多久,
02:50
and what's the pathway back to 350.
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還有要如何讓它降回350。
02:53
Now, why is this so complicated?
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為什麼這件事會那麼複雜呢?
02:55
Why don't we know some of these things a little bit better?
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為何我們還不太了解這些事呢?
02:57
Well, the problem is that
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嗯,問題在於
02:59
we've got very complicated forces in the climate system.
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氣候系統裡有很複雜的力量存在。
03:01
There's all kinds of natural causes of climate change.
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有許多導致氣候變遷的自然因素。
03:04
There's air-sea interactions.
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有空氣和海洋的相互作用。
03:06
Here in Galapagos,
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在加拉巴哥群島這裡,
03:08
we're affected by El Ninos and La Nina.
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我們被聖嬰和反聖嬰現象所影響著。
03:10
But the entire planet warms up when there's a big El Nino.
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但是當巨大的聖嬰現象出現時,整個地球都會出現暖化現象。
03:13
Volcanoes eject aerosols into the atmosphere.
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火山噴出的氣體會曠散到大氣中。
03:16
That changes our climate.
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這會改變氣候。
03:18
The ocean contains most of the exchangeable heat on the planet.
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海洋含有地球上最大量的可交換熱能。
03:21
So anything that influences
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因此任何能夠影響
03:23
how ocean surface waters mix with the deep water
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海洋表層與深海海水混合的因素
03:26
changes the ocean of the planet.
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將會改變地球上的海洋。
03:28
And we know the solar output's not constant through time.
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我們知道太陽照射的能量並不是永遠都固定的。
03:31
So those are all natural causes of climate change.
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所以這些都是導致氣候變遷的自然因素。
03:34
And then we have the human-induced causes
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然而,我們還有因為人類所造成的
03:36
of climate change as well.
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氣候變遷因素。
03:38
We're changing the characteristics of the surface of the land,
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我們正在改變地表的特質,
03:40
the reflectivity.
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所謂的反射率。
03:42
We inject our own aerosols into the atmosphere,
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我們排放氣體到大氣中,
03:44
and we have trace gases, and not just carbon dioxide --
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我們追蹤了幾種氣體,不只是二氧化碳 --
03:47
it's methane, ozone,
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還有甲烷、臭氧、
03:49
oxides of sulfur and nitrogen.
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以及硫和氮的氧化物。
03:51
So here's the thing. It sounds like a simple question.
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所以事情就是這樣。聽起來似乎是個簡單的問題。
03:53
Is CO2 produced by man's activities
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人類活動所產生的二氧化碳
03:56
causing the planet to warm up?
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導致了全球暖化嗎?
03:58
But to answer that question,
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但是想回答那個問題,
04:00
to make a clear attribution to carbon dioxide,
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想了解二氧化碳扮演的角色,
04:03
you have to know something about
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你就必須先了解
04:05
all of these other agents of change.
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所有造成氣候變遷的其它因素。
04:07
But the fact is we do know a lot about all of those things.
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但事實上我們確實知道許多關於這些的資訊。
04:10
You know, thousands of scientists
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你知道嗎,有上千位科學家
04:12
have been working on understanding
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正在致力於了解
04:14
all of these man-made causes
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這些人為因素
04:16
and the natural causes.
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以及自然因素。
04:18
And we've got it worked out, and we can say,
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而且我們已經弄清楚了,我們可以說,
04:21
"Yes, CO2 is causing the planet to warm up now."
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"是的,二氧化碳正在造成全球暖化現象。"
04:25
Now, we have many ways to study natural variability.
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目前我們有許多方法來研究自然界的變異性。
04:28
I'll show you a few examples of this now.
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現在讓我給你們看一些例子。
04:30
This is the ship that I spent the last three months on in the Antarctic.
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這是我最近三個月來在南極待的那艘船。
04:33
It's a scientific drilling vessel.
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這是一艘科學鑽探船。
04:36
We go out for months at a time and drill into the sea bed
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每次出海都會航行好幾個月,然後鑽入海床
04:39
to recover sediments
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收集一些沉積物,
04:41
that tell us stories of climate change, right.
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這東西可以讓我們了解氣候變遷的狀況,對吧。
04:44
Like one of the ways to understand our greenhouse future
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例如,想了解未來溫室效應狀況的其中一個方法
04:47
is to drill down in time
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就是下向挖掘,從現今的部份
04:49
to the last period
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到最後一個時期,
04:51
where we had CO2 double what it is today.
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我們發現那裡的二氧化碳含量是現在的兩倍。
04:53
And so that's what we've done with this ship.
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那就是我們在這艘船上完成的工作。
04:55
This was -- this is south of the Antarctic Circle.
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這邊是南極圈的南邊。
04:58
It looks downright tropical there.
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它看起來簡直就像熱帶地區。
05:00
One day where we had calm seas and sun,
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某天海水平靜,陽光和煦的時候,
05:03
which was the reason I could get off the ship.
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也就是我能夠下船的原因。
05:05
Most of the time it looked like this.
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在大部分時候看起來就像這樣。
05:07
We had a waves up to 50 ft.
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海浪高達50呎,
05:10
and winds averaging
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而在大部分航行中
05:12
about 40 knots for most of the voyage
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風速平均是40節(約時速74公里),
05:14
and up to 70 or 80 knots.
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最高可達70~80節(時速130~150公里)。
05:16
So that trip just ended,
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於是那趟旅程到此結束,
05:18
and I can't show you too many results from that right now,
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我現在還有沒辦法給你們看許多當時的結果,
05:20
but we'll go back one more year,
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但我們來看看前一年,
05:22
to another drilling expedition I've been involved in.
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我曾參予過的另一項鑽探工程。
05:25
This was led by Ross Powell and Tim Naish.
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這是由Ross Powell和Tim Naish所主導的。
05:28
It's the ANDRILL project.
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這個項目叫ANDRILL。
05:30
And we made the very first bore hole
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而我們所鑚的第一個鑽孔,
05:32
through the largest floating ice shelf on the planet.
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是從地球上最大的浮冰層開始的。
05:34
This is a crazy thing, this big drill rig wrapped in a blanket
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這是一件很瘋狂的事。這個巨大的鑚探設備被毛毯包裹著,
05:37
to keep everybody warm,
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以保持大家的溫暖,
05:39
drilling at temperatures of minus 40.
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在零下40度的低溫下進行鑚探作業。
05:41
And we drilled in the Ross Sea.
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我們在羅斯海中進行鑽探。
05:43
That's the Ross Sea Ice Shelf on the right there.
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那邊那個就是羅斯海的冰層。
05:46
So, this huge floating ice shelf
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那麼,這塊有如阿拉斯加那麼大的
05:48
the size of Alaska
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巨大浮冰層,
05:50
comes from West Antarctica.
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是從西南極飄過來的。
05:52
Now, West Antarctica is the part of the continent
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現在,西南極成為大陸版塊的一部份,
05:55
where the ice is grounded on sea floor
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冰層在海底積聚,
05:57
as much as 2,000 meters deep.
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在深達2000公尺的地方。
06:00
So that ice sheet is partly floating,
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因此那塊冰層有一部分是浮起來的,
06:02
and it's exposed to the ocean, to the ocean heat.
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它暴露在海洋中,在海洋的熱氣中。
06:06
This is the part of Antarctica that we worry about.
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這是南極令我們擔心的其中一件事。
06:08
Because it's partly floating, you can imagine,
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由於它有部份是浮起來的,你可以想像,
06:10
is sea level rises a little bit,
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只要海平面上升一點點,
06:12
the ice lifts off the bed, and then it can break off and float north.
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冰層會從海底浮上來,然後會裂開,並朝向北邊漂移。
06:15
When that ice melts, sea level rises by six meters.
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一旦冰層溶化,海平面就會上升6公尺。
06:19
So we drill back in time to see how often that's happened,
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所以我們利用鑚探方式來研究這種事發生的頻率,
06:22
and exactly how fast that ice can melt.
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以及冰層實際溶化的速度有多快。
06:25
Here's the cartoon on the left there.
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左邊這裡有一個插畫。
06:28
We drilled through a hundred meters of floating ice shelf
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我們鑽過厚達一百公尺的浮冰層,
06:31
then through 900 meters of water
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然後穿過900公尺深的海水,
06:33
and then 1,300 meters into the sea floor.
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然後再往下進入海底1300公尺深。
06:36
So it's the deepest geological bore hole ever drilled.
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這是有史以來最深的地質鑚探。
06:39
It took about 10 years to put this project together.
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這個項目大概花了10年的籌備工作。
06:42
And here's what we found.
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這是我們所發現的東西。
06:44
Now, there's 40 scientists working on this project,
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現在,有40位科學家正在進行這個項目,
06:46
and people are doing all kinds of really complicated
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還有許多人在進行各種既複雜
06:48
and expensive analyses.
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又昂貴的分析作業。
06:51
But it turns out, you know, the thing that told the best story
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但結果呢,最能說明一切的
06:54
was this simple visual description.
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就是這個簡單的視覺描述。
06:56
You know, we saw this in the core samples as they came up.
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當樣品被採集出來時,我們在核心樣品中發現這個。
06:59
We saw these alternations
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我們在沉積物裡面發現
07:01
between sediments that look like this --
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這些交替層,看起來就像這樣 --
07:03
there's gravel and cobbles in there
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裡面有碎石和圓石,
07:05
and a bunch of sand.
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還有大量的沙子。
07:07
That's the kind of material in the deep sea.
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這就是深海裡面的物質。
07:09
It can only get there if it's carried out by ice.
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它是被冰層所帶過去的。
07:12
So we know there's an ice shelf overhead.
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我們知道冰層就在它的上面。
07:14
And that alternates with a sediment that looks like this.
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而這個含有沉積物的交替層看起來就像這樣。
07:17
This is absolutely beautiful stuff.
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這絕對是很美的東西。
07:19
This sediment is 100 percent made up
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這些沉積物是百分之百
07:21
of the shells of microscopic plants.
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由微小植物的外皮所形成的。
07:24
And these plants need sunlight,
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而這些植物需要陽光,
07:26
so we know when we find that sediment
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所以當我們找到那些沉積物時便知道,
07:28
there's no ice overhead.
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它的上面沒有冰層。
07:30
And we saw about 35 alternations
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在開放水域和冰層覆蓋的水域中
07:32
between open water and ice-covered water,
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我們發現了大概35個交替層,
07:35
between gravels and these plant sediments.
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位於碎石和這些植物沉積物之間。
07:38
So what that means is, what it tells us
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所以意思是說,它能告訴我們,
07:41
is that the Ross Sea region, this ice shelf,
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在羅斯海域的這塊冰層,
07:44
melted back and formed anew
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曾經溶化又再次形成冰層
07:46
about 35 times.
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重複大約35次。
07:48
And this is in the past four million years.
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而這是在過去400萬年發生的事。
07:52
This was completely unexpected.
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這是完全出乎意料的。
07:54
Nobody imagined that the West Antarctic Ice Sheet
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沒有人能夠想像西南極洲冰原
07:56
was this dynamic.
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是如此多變的。
07:58
In fact, the lore for many years has been,
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事實上,多年來的認知一直以為,
08:01
"The ice formed many tens of millions of years ago,
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"這些冰層是在幾千萬年前形成的,
08:03
and it's been there ever since."
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並且從未改變過。"
08:05
And now we know that in our recent past
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現在我們知道在接近現今的過去,
08:07
it melted back and formed again,
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它曾經溶化又再次形成冰層,
08:09
and sea level went up and down, six meters at a time.
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每次海平面上升和下降幅度大約6公尺。
08:12
What caused it?
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這是什麼造成的呢?
08:14
Well, we're pretty sure that it's very small changes
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嗯, 我們非常確定在南極洲
08:16
in the amount of sunlight reaching Antarctica,
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太陽光的照射量並沒有什麼改變,
08:19
just caused by natural changes in the orbit of the Earth.
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只有因為地球軌道造成的少許自然變異。
08:22
But here's the key thing:
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但是,接下來的才是關鍵:
08:24
you know, the other thing we found out
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你知道嗎, 我們發現另一件事情,
08:26
is that the ice sheet passed a threshold,
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就是冰層已經超過了一個臨界點,
08:28
that the planet warmed up enough --
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地球暖化的程度已經高到足以 --
08:30
and the number's about one degree to one and a half degrees Centigrade --
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大概在 1 到 1.5 攝氏度 --
08:32
the planet warmed up enough that it became ...
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地球暖化的程度已經高到足以讓 ...
08:35
that ice sheet became very dynamic
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冰層變得非常的不穩定,
08:37
and was very easily melted.
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變得很容易溶化。
08:39
And you know what?
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你能想像嗎?
08:41
We've actually changed the temperature in the last century
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我們在上一個世紀,
08:43
just the right amount.
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讓溫度上升的幅度就是這個數字。
08:45
So many of us are convinced now
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因此我們大多都相信,
08:48
that West Antarctica, the West Antarctic Ice Sheet, is starting to melt.
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西南極,西南極洲冰原已經開始溶化了。
08:51
We do expect to see a sea-level rise
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我們已經可以預期在這個世紀末,
08:54
on the order of one to two meters by the end of this century.
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海平面將會上升一到兩公尺高。
08:57
And it could be larger than that.
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而且還可能會更高。
09:00
This is a serious consequence
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這對吉里巴斯這類的國家,
09:02
for nations like Kiribati,
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會是一個很嚴重的結果,
09:04
you know, where the average elevation
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你知道的,他們地表的平均高度
09:06
is about a little over a meter above sea level.
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只比海平面高出一公尺左右。
09:08
Okay, the second story takes place here in Galapagos.
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第二個問題發生在加拉巴哥群島。
09:11
This is a bleached coral,
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這兒發生了珊瑚的白化現象,
09:13
coral that died during the 1982-'83 El Nino.
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珊瑚因為1982-83年的聖嬰現象而死亡。
09:16
This is from Champion Island.
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這件事發生在冠軍島上。
09:18
It's about a meter tall Pavona clavus colony.
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那是長達1公尺的柱形雀屏珊瑚群。
09:21
And it's covered with algae. That's what happens.
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最後它被海藻所覆蓋。事情就這樣發生了。
09:24
When these things die,
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當這些珊瑚死亡後,
09:26
immediately, organisms come in
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立刻有一些有機生物了進來,
09:28
and encrust and live on that dead surface.
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包覆並寄居在這死掉的珊瑚表面上。
09:31
And so, when a coral colony is killed
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所以,當珊瑚群
09:33
by an El Nino event,
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因為聖嬰現象而死亡後,
09:35
it leaves this indelible record.
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便會留下這個無法消去的紀錄。
09:37
You can go then and study corals
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你可以到那兒,然後研究這些珊瑚,
09:39
and figure out how often do you see this.
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看看你有多常遇到這種事情。
09:41
So one of the things thought of in the '80s
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所以在80年代有一個概念,
09:43
was to go back and take cores
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就是到那兒去,
09:45
of coral heads throughout the Galapagos
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將散落於加拉巴哥群島的珊瑚頭部核心取出,
09:47
and find out how often was there a devastating event.
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研究這種毀滅性事件發生的頻率。
09:50
And just so you know, 1982-'83,
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如你所知的,在1982-83年間,
09:53
that El Nino killed 95 percent
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聖嬰現象導致加拉巴哥群島
09:55
of all the corals here in Galapagos.
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95%的珊瑚死去。
09:58
Then there was similar mortality in '97-'98.
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而在1997-98年間有著類似的死亡率。
10:01
And what we found
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而我們因為挖掘而發現
10:03
after drilling back in time two to 400 years
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追朔過去2年到400年間,
10:05
was that these were unique events.
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這是很罕見的現象。
10:07
We saw no other mass mortality events.
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我們沒有發現其他大量死亡的事件。
10:10
So these events in our recent past really are unique.
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所以這些事件在最近幾百年中是相當罕見的。
10:13
So they're either just truly monster El Ninos,
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所以這些聖嬰現象要不就是一個大怪獸,
10:15
or they're just very strong El Ninos
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又或者只是很強烈聖嬰現象
10:17
that occurred against a backdrop of global warming.
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恰巧遇上了全球暖化。
10:21
Either case, it's bad news
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不論是哪一種狀況,
10:23
for the corals of the Galapagos Islands.
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對於加拉巴哥群島的珊瑚來說都是壞消息。
10:27
Here's how we sample the corals.
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接下來是我們採集珊瑚樣本的方式。
10:29
This is actually Easter Island. Look at this monster.
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這兒是復活節島。看看這個怪物。
10:32
This coral is eight meters tall, right.
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這珊瑚長達八公尺。
10:35
And it been growing for about 600 years.
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它已經生長了大約六百年的時間。
10:37
Now, Sylvia Earle turned me on to this exact same coral.
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Sylvia Earle 曾經用同樣的珊瑚引起我的興趣。
10:40
And she was diving here with John Lauret -- I think it was 1994 --
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她曾經和 John Lauret 在這兒潛水 -- 我想那是 1994 年的事 --
10:43
and collected a little nugget and sent it to me.
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並且收集了一些碎片寄給我。
10:45
And we started working on it,
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然後我們開始進行研究,
10:47
and we figured out we could tell the temperature of the ancient ocean
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於是我們發現我們藉由分析這類珊瑚
10:49
from analyzing a coral like this.
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來得知古代海洋的溫度。
10:52
So we have a diamond drill.
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所以我們準備了鑽石鑽頭。
10:54
We're not killing the colony; we're taking a small core sample out of the top.
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我們不會毀掉整個珊瑚群,我們只是拿取核心頂端的一小塊樣本。
10:57
The core comes up as these cylindrical tubes of limestone.
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當石灰岩柱被推到上方時,這些核心就會跑上來。
11:00
And that material then we take back to the lab and analyze it.
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之後我們會將這些物質帶回實驗室進行分析。
11:04
You can see some of the coral cores there on the right.
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你可以在右邊看見一些珊瑚的核心。
11:07
So we've done that all over the Eastern Pacific.
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我們已經針對整個東太平洋進行了這個分析。
11:09
We're starting to do it in the Western Pacific as well.
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我們也開始針對西太平洋進行研究。
11:12
I'll take you back here to the Galapagos Islands.
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接下來我們在繼續談加拉巴哥群島。
11:14
And we've been working at this fascinating uplift here in Urbina Bay.
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我們在爾比納海岸針對這令人感興趣的地層隆起進行研究。
11:17
That the place where,
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這個地方,
11:19
during an earthquake in 1954,
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在1954年的地震當中,
11:21
this marine terrace was lifted up
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這個海階相當迅速地
11:23
out of the ocean very quickly,
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從海裡被推出海平面,
11:26
and it was lifted up about six to seven meters.
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它被提升了大約六到七公尺高。
11:29
And so now you can walk through a coral reef without getting wet.
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所以現在你可以走過珊瑚礁都不會碰到水。
11:32
If you go on the ground there, it looks like this,
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如果你在這兒晃的話,看起來就像這樣,
11:34
and this is the grandaddy coral.
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這是一株老祖父級的珊瑚。
11:36
It's 11 meters in diameter,
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它的直徑有十一公尺寬,
11:38
and we know that it started growing
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我們知道它從1584年
11:40
in the year 1584.
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就開始生長到現在。
11:42
Imagine that.
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想像一下。
11:44
And that coral was growing happily in those shallow waters,
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這珊瑚本來開心的在淺水灘裡生長著,
11:47
until 1954, when the earthquake happened.
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直到1954年地震發生。
11:50
Now the reason we know it's 1584
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我們之所以知道它生長於1584年,
11:52
is that these corals have growth bands.
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是因為珊瑚有這些年輪。
11:54
When you cut them, slice those cores in half and x-ray them,
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當你將它們切開,將核心切成一半然後用X光分析,
11:57
you see these light and dark bands.
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你會看見這些黑白相間的環。
11:59
Each one of those is a year.
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每一圈代表一年。
12:01
We know these corals grow about a centimeter and a half a year.
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我們知道這些珊瑚每年大約生長1.5公分左右。
12:03
And we just count on down to the bottom.
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我們由下面計算到底部。
12:06
Then their other attribute is
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它們另一個性質是,
12:08
that they have this great chemistry.
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它們有著很棒的化學成份。
12:10
We can analyze the carbonate
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我們可以針對碳酸鹽
12:12
that makes up the coral,
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珊瑚的主成份進行分析,
12:14
and there's a whole bunch of things we can do.
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還有許多分析我們可以作。
12:16
But in this case, we measured the different isotopes of oxygen.
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在這個例子裡,我們量測了不同氧的同位素。
12:19
Their ratio tells us the water temperature.
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它們的比例可以讓我們知道海水的溫度。
12:21
In this example here,
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在這個例子裡,
12:23
we had monitored this reef in Galapagos
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我們藉由這個溫度紀錄器
12:25
with temperature recorders,
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來監測加拉巴哥群島的珊瑚礁。
12:27
so we know the temperature of the water the coral's growing in.
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於是我們可以得知珊瑚生長環境的海水溫度。
12:30
Then after we harvest a coral, we measure this ratio,
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當我們採收珊瑚之後,我們量測這個同位素的比例,
12:33
and now you can see, those curves match perfectly.
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然後你可以發現,這些曲線的結果相當吻合。
12:36
In this case, at these islands,
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在這個例子中,在這些島嶼裡,
12:38
you know, corals
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如你所見,珊瑚在水裡
12:40
are instrumental-quality recorders of change in the water.
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可以當作測溫度變化的高品質記錄器。
12:43
And of course, our thermometers
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當然,我們的溫度計
12:45
only take us back 50 years or so here.
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只能讓我們知道近50年左右的溫度。
12:47
The coral can take us back
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而這些珊瑚
12:49
hundreds and thousands of years.
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可以讓我們知道近百年甚至千年的溫度。
12:51
So, what we do:
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所以我們做了什麼呢?
12:53
we've merged a lot of different data sets.
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我們整合了許多不同的數據組。
12:56
It's not just my group; there's maybe 30 groups worldwide doing this.
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並不只有我的團隊,世界上還有將近30組的團隊在進行這件事。
12:59
But we get these instrumental- and near-instrumental-quality records
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但是,我們使用這種高品質記錄器
13:02
of temperature change that go back hundreds of years,
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得出幾百年來的溫度變化紀錄,
13:04
and we put them together.
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然後我們將這些數據整合在一起。
13:06
Here's a synthetic diagram.
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這是一個綜合的圖表。
13:08
There's a whole family of curves here.
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有許多的曲線組在這裡。
13:10
But what's happening: we're looking at the last thousand years
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這代表什麼呢? 我們正在看的,
13:13
of temperature on the planet.
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是這個星球幾百年來的溫度紀錄。
13:15
And there's five or six different compilations there,
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這裡有5~6種不同的版本,
13:17
But each one of those compilations reflects input
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但每一種版本所對應的是
13:20
from hundreds of these kinds of records from corals.
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由幾百種珊瑚所取得的溫度紀錄。
13:23
We do similar things with ice cores.
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我們也對冰核作同樣的分析研究。
13:26
We work with tree rings.
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我們研究這些冰輪。
13:28
And that's how we discover
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這是我們用來發掘
13:30
what is truly natural
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真正的自然現象
13:32
and how different is the last century, right?
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以及上一個世紀有什麼不同的方式,對吧。
13:35
And I chose this one
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因為它的複雜且紊亂的外表,
13:37
because it's complicated and messy looking, right.
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所以我選了這個。
13:40
This is as messy as it gets.
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這和剛取得時一樣紊亂。
13:42
You can see there's some signals there.
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你可以看見這兒傳遞出一些訊息。
13:45
Some of the records
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某些紀錄
13:47
show lower temperatures than others.
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顯示著溫度比其它還來得低。
13:49
Some of them show greater variability.
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某些顯示著很大的變異性。
13:52
But they all tell us
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但這也正告訴我們,
13:54
what the natural variability is.
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自然有多麼的多變。
13:56
Some of them are from the northern hemisphere;
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有一部分是來自於北半球。
13:58
some are from the entire globe.
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某些是來自世界各地。
14:00
But here's what we can say:
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不過我們可以這樣說,
14:02
what's natural in the last thousand years is that the planet was cooling down.
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在過去千年的時間中,這個星球溫度一直在下降。
14:05
It was cooling down
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它不停的降溫,
14:07
until about 1900 or so.
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直到1900年左右。
14:09
And there is natural variability
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然而,有一些自然的變數,
14:11
caused by the Sun, caused by El Ninos.
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例如太陽的影響,例如聖嬰現象的影響。
14:14
A century-scale, decadal-scale variability,
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累計數十年到數百年的變化,
14:16
and we know the magnitude;
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我們知道他的影響性,
14:18
it's about two-tenths to four-tenths of a degree Centigrade.
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大概是在0.2到0.4攝氏度左右。
14:21
But then at the very end is where
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但是在最後,
14:23
we have the instrumental record in black.
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我們發現了隱藏的紀錄。
14:25
And there's the temperature up there in 2009.
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在2009年的溫度是一個高點。
14:28
You know, we've warmed the globe
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你知道我們在上一個世紀,
14:30
about a degree Centigrade in the last century,
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讓地球上升了一攝氏度,
14:33
and there's nothing
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而在自然界的紀錄中,
14:35
in the natural part of that record
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從未曾有過任何跡象顯示,
14:37
that resembles what we've seen in the last century.
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過去這個世紀的問題曾經發生過。
14:39
You know, that's the strength of our argument,
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這就是我們論點的說服力所在,
14:41
that we are doing something that's truly different.
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我們所做的是完全不一樣的事情。
14:45
So I'll close with a short discussion
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所以我將再談一小段海洋酸化問題
14:48
of ocean acidification.
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來作為今天的結論。
14:51
I like it as a component of global change to talk about,
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我想將它視為地球暖化問題的一部分來談,
14:54
because, even if you are a hard-bitten global warming skeptic,
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因為,即使你不相信地球暖化問題,
14:58
and I talk to that community fairly often,
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我常和這種人談話,
15:00
you cannot deny
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但你不能夠否認
15:02
the simple physics
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二氧化碳會溶入海水
15:04
of CO2 dissolving in the ocean.
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這種簡單的物理現象。
15:07
You know, we're pumping out lots of CO2 into the atmosphere,
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你知道我們正在排放大量的二氧化碳到大氣層中,
15:10
from fossil fuels, from cement production.
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不論是從石化原料或是水泥製品。
15:13
Right now, about a third of that carbon dioxide
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現在, 大概有1/3的二氧化碳
15:15
is dissolving straight into the sea, right?
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會直接溶入海水中,對吧?
15:17
And as it does so,
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而當它發生的時候,
15:19
it makes the ocean more acidic.
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它就會讓海水變得更酸一點。
15:22
So, you cannot argue with that.
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所以你無法去爭論這件事。
15:24
That is what's happening right now,
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這就是正在發生的事情,
15:26
and it's a very different issue
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而這個和地球暖化
15:28
than the global warming issue.
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是完全不同的事情。
15:30
It has many consequences.
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這會造成許多後果。
15:32
There's consequences for carbonate organisms.
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對於碳酸鹽類的有機生物會產生影響。
15:35
There are many organisms
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有許多有機生物
15:37
that build their shells out of calcium carbonate --
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居住在碳酸鈣作成的甲殼之中 --
15:39
plants and animals both.
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不論是植物或動物。
15:42
The main framework material of coral reefs
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像是珊瑚礁的主要骨架原料
15:44
is calcium carbonate.
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就是碳酸鈣。
15:46
That material is more soluble
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這種原料在酸性的液體中
15:48
in acidic fluid.
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會比較容易溶解的。
15:51
So one of the things we're seeing
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所以我們會發現
15:53
is organisms are having
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這些有機生物必須
15:55
to spend more metabolic energy
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付出更多的新陳代謝能量
15:57
to build and maintain their shells.
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來製造或是維持它們的甲殼完整。
15:59
At some point, as this transience,
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就在這個現象發生的同時,
16:01
as this CO2 uptake in the ocean continues,
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當二氧化碳持續溶入海水中,
16:04
that material's actually going to start to dissolve.
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這些物質將會開始溶解。
16:06
And on coral reefs,
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於是那些居住在珊瑚礁
16:08
where some of the main framework organisms disappear,
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主骨架上的那些有機生物逐漸消失,
16:11
we will see a major loss
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我們將會發現海洋生物的多元性
16:13
of marine biodiversity.
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正在逐漸的減少。
16:15
But it's not just the carbonate producers that are affected.
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但並不只是碳酸鹽產物會受到影響。
16:18
There's many physiological processes
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許多的生理現象也會
16:21
that are influenced by the acidity of the ocean.
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因為海洋的酸化而受到影響。
16:24
So many reactions involving enzymes and proteins
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許多跟酵素和蛋白質相關的反應
16:27
are sensitive to the acid content of the ocean.
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對於海洋的酸度都很敏感。
16:30
So, all of these things --
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所以,所有這類的事情 --
16:32
greater metabolic demands,
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造成更大的新陳代謝需求,
16:34
reduced reproductive success,
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改變了呼吸系統與新陳代謝系統,
16:36
changes in respiration and metabolism.
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同時降低了受孕的成功率。
16:39
You know, these are things that we have good physiological reasons
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我們可以找出許多完整的生理學解釋,
16:42
to expect to see stressed
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讓我們知道這個現象
16:44
caused by this transience.
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會導致這些可預期的問題。
16:46
So we figured out some pretty interesting ways
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於是我們發現了一些有意思的方式
16:48
to track CO2 levels in the atmosphere,
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來追蹤過去幾百年中
16:51
going back millions of years.
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二氧化碳跑進大氣中的數量。
16:53
We used to do it just with ice cores,
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我們原本只是把它用在冰核之中,
16:55
but in this case, we're going back 20 million years.
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但是在這裡,我們將可以追朔到兩千萬年前。
16:58
And we take samples of the sediment,
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我們取了一些沉積物的樣品,
17:00
and it tells us the CO2 level of the ocean,
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它可以讓我們知道海洋中的二氧化碳含量,
17:03
and therefore the CO2 level of the atmosphere.
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於是可以知道大氣中二氧化碳的含量。
17:05
And here's the thing:
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這就是怎麼作到的:
17:07
you have to go back about 15 million years
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你必須先回到一千五百萬年前,
17:09
to find a time when CO2 levels
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找到二氧化碳含量
17:12
were about what they are today.
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和今日差不多的時代。
17:14
You have to go back about 30 million years
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你必須到三千萬年前,
17:16
to find a time when CO2 levels
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找到二氧化氮含量
17:18
were double what they are today.
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是今日兩倍的時代。
17:20
Now, what that means is
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意思是說,
17:22
that all of the organisms that live in the sea
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居住在海中的生物
17:24
have evolved in this chemostatted ocean,
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在這個穩定的海洋之中演化,
17:27
with CO2 levels lower than they are today.
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從海中的二氧化碳含量比現今更低的時候開始。
17:30
That's the reason that they're not able to respond or adapt
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因為它們無法承受或適應
17:33
to this rapid acidification
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現在正在逐漸
17:36
that's going on right now.
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不停的變酸的海水。
17:38
So, Charlie Veron
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所以 Charlie Veron
17:40
came up with this statement last year:
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去年說了這段話:
17:42
"The prospect of ocean acidification
436
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"海洋酸化現象將會是
17:44
may well be the most serious
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所有人為二氧化碳排放
17:46
of all of the predicted outcomes
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所導致的可預期問題中
17:48
of anthropogenic CO2 release."
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最嚴重的一個。"
17:51
And I think that may very well be true,
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而我想這將會成真,
17:54
so I'll close with this.
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所以我用這個來做為結論。
17:56
You know, we do need the protected areas, absolutely,
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我們絕對需要去規劃出保護區,
17:59
but for the sake of the oceans,
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但是為了海洋的未來,
18:01
we have to cap or limit CO2 emissions
444
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我們需要的是去遮蔽或限制二氧化碳的排放量,
18:03
as soon as possible.
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而且是越快越好。
18:05
Thank you very much.
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謝謝大家。
18:07
(Applause)
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(掌聲)
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