Mission Blue Voyage
Rob Dunbar: Discovering ancient climates in oceans and ice
罗伯邓巴尔：在海洋和冰层中追寻远古气候
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罗伯邓巴尔不断收集一万二千年前的气候数据，在远古海床、珊瑚石和冰层内寻找线索。他的工作对于我们为调整现在的气候而设定基准线——也对追踪日益严重的海洋酸化十分重要。
Rob Dunbar - Oceanographer, biogeochemist
Rob Dunbar looks deeply at ancient corals and sediments to study how the climate and the oceans have shifted over the past 50 to 12,000 years -- and how the Antarctic ecosystem is changing right now. Full bio
Rob Dunbar looks deeply at ancient corals and sediments to study how the climate and the oceans have shifted over the past 50 to 12,000 years -- and how the Antarctic ecosystem is changing right now. Full bio
Double-click the English transcript below to play the video.
00:15
If you really want to understand
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如果你想真正了解
00:18
the problem that we're facing with the oceans,
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我们所面对的海洋问题，
00:21
you have to think about the biology
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你就必须在考虑到物理学的同时
00:23
at the same time you think about the physics.
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也考虑到生物学。
00:26
We can't solve the problems
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我们不可能解决问题，
00:28
unless we start studying the ocean
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除非我们开始用一种
00:30
in a very much more interdisciplinary way.
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跨学科的方式来研究海洋。
00:33
So I'm going to demonstrate that through
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所以我会通过对发生在海洋中的
00:35
discussion of some of the climate change things that are going on in the ocean.
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一些气候变化的讨论来阐释我的观点。
00:38
We'll look at sea level rise.
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我们会看到海平面上升。
00:40
We'll look at ocean warming.
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我们会看到海洋变暖。
00:42
And then the last thing on the list there, ocean acidification --
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那么在这张单子的最下面是，海洋酸化——
00:45
if you were to ask me, you know, "What do you worry about the most?
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如果你要问我，“你最担心发生什么？
00:48
What frightens you?"
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什么最让你害怕？”
00:50
for me, it's ocean acidification.
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对于我来说，那就是海洋酸化。
00:52
And this has come onto the stage pretty recently.
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而且这件事已迫在眉睫。
00:54
So I will spend a little time at the end.
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所以最后我会花一点时间来讲它。
00:57
I was in Copenhagen in December
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12月份我在哥本哈根
00:59
like a number of you in this room.
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就像你们一样，在这样的房间里。
01:01
And I think we all found it, simultaneously,
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然后我想我们大家都发现这是
01:04
an eye-opening
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一次令人大开眼界
01:06
and a very frustrating experience.
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同时也非常令人沮丧的经历。
01:08
I sat in this large negotiation hall,
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我坐在这样大的交流厅里，
01:11
at one point, for three or four hours,
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从某种程度上讲，大概坐了有3到4个小时，
01:13
without hearing the word "oceans" one time.
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却听不到“海洋”这个词。
01:17
It really wasn't on the radar screen.
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它确实不在讨论范围内。
01:20
The nations that brought it up
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当轮到各个国家的领导人发言时，
01:22
when we had the speeches of the national leaders --
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某个国家才把这个话题提出来。
01:24
it tended to be the leaders of the small island states,
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这好像是那些小的岛国
01:27
the low-lying island states.
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也就是那些低海拔岛国的的领导人。
01:29
And by this weird quirk
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这些低海拔的国家，
01:31
of alphabetical order of the nations,
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如基里巴斯和瑙鲁，
01:34
a lot of the low-lying states,
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因为按照字母顺序排列国家的原因，
01:36
like Kiribati and Nauru,
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他们（的领导人）坐在
01:38
they were seated at the very end of these immensely long rows.
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这些长长队伍中非常靠后的位置。
01:41
You know, they were marginalized
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大家知道，在这个交流大厅里
01:43
in the negotiation room.
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他们被边缘化了。
01:45
One of the problems
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问题之一就是
01:47
is coming up with the right target.
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选择正确的目标。
01:49
It's not clear what the target should be.
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我们还不清楚我们的目标是什么。
01:51
And how can you figure out how to fix something
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如果没有清晰的目标，
01:53
if you don't have a clear target?
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我们怎么去搞明白我们应如何解决问题？
01:55
Now, you've heard about "two degrees":
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现在，大家已经听说“2摄氏度”：
01:57
that we should limit temperature rise to no more than two degrees.
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也就是说我们不应该让气温上升超过2摄氏度。
02:00
But there's not a lot of science behind that number.
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但在这个数字的背后并没有很充分的科学道理。
02:03
We've also talked about
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我们也谈到
02:05
concentrations of carbon dioxide in the atmosphere.
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在大气层中二氧化碳的集聚浓度问题。
02:07
Should it be 450? Should it be 400?
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它应该是450ppm？或是400ppm？（注：ppm即百万分之，这里用作浓度计量单位）
02:10
There's not a lot of science behind that one either.
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在那个数字背后也没有很多的科学道理。
02:13
Most of the science that is behind these numbers,
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在这些数字背后的大多数科学道理，
02:15
these potential targets,
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这些潜在的目标，
02:17
is based on studies on land.
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依据的是陆地上的研究。
02:19
And I would say, for the people that work in the ocean
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而且我会说，对那些研究海洋
02:22
and think about what the targets should be,
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并且思索着设定什么样的目标的人来说，
02:24
we would argue that they must be much lower.
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我们会辩驳说，这些数据必须要更低。
02:26
You know, from an oceanic perspective,
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大家知道，从海洋的视角来看，
02:28
450 is way too high.
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450ppm未免太高了。
02:30
Now there's compelling evidence
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现在有非常显著的证据表明，
02:32
that it really needs to be 350.
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这个浓度应该是350ppm。
02:34
We are, right now, at 390 parts per million
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我们当前大气层里二氧化碳的浓度
02:37
of CO2 in the atmosphere.
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是390ppm。
02:39
We're not going to put the brakes on in time to stop at 450,
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我们并不打算及时踩刹车以停在450ppm，
02:42
so we've got to accept we're going to do an overshoot,
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所以我们得接受二氧化碳浓度将冲过头的事实，
02:45
and the discussion as we go forward
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并且正如我们将要进行的讨论
02:47
has to focus on how far the overshoot goes
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必须集中在这个“头”究竟过了多少，
02:50
and what's the pathway back to 350.
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我们如何能够让它降低到350。
02:53
Now, why is this so complicated?
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那么，为什么这个事情如此复杂？
02:55
Why don't we know some of these things a little bit better?
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我们为什么不能对这些事知之更深呢？
02:57
Well, the problem is that
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嗯，问题就在于
02:59
we've got very complicated forces in the climate system.
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在气候系统中存在非常复杂的动力源。
03:01
There's all kinds of natural causes of climate change.
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所有种类的自然力都能导致气候的变化。
03:04
There's air-sea interactions.
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这里有大气--海洋交互作用。
03:06
Here in Galapagos,
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就在加拉帕戈斯群岛，
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we're affected by El Ninos and La Nina.
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我们被厄尔尼诺和拉尼娜现象困扰。
03:10
But the entire planet warms up when there's a big El Nino.
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但是当发生大型厄尔尼诺现象时，整个地球都会变暖。
03:13
Volcanoes eject aerosols into the atmosphere.
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火山将气溶胶喷射进大气层。
03:16
That changes our climate.
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那会改变我们的气候。
03:18
The ocean contains most of the exchangeable heat on the planet.
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海洋包含了这个星球上大部分的可交换热量。
03:21
So anything that influences
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所以，任何事情，
03:23
how ocean surface waters mix with the deep water
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只要它影响了海洋表面水层和深海水层的混合
03:26
changes the ocean of the planet.
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它就会改变海洋。
03:28
And we know the solar output's not constant through time.
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而且我们知道，随着时间的变化，太阳能的输出并不恒定。
03:31
So those are all natural causes of climate change.
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因此这些都是影响气候变化的自然因素。
03:34
And then we have the human-induced causes
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然后，我们又有了人类诱发的
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of climate change as well.
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影响气候变化的因素。
03:38
We're changing the characteristics of the surface of the land,
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我们正在改变地表的某些特征，
03:40
the reflectivity.
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比如反射率。
03:42
We inject our own aerosols into the atmosphere,
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我们把自己制造的气溶胶发射到大气层里，
03:44
and we have trace gases, and not just carbon dioxide --
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我们也排放痕量（即微量）气体，不仅仅是二氧化碳——
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it's methane, ozone,
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包括甲烷，臭氧，
03:49
oxides of sulfur and nitrogen.
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硫和氮氧化物。
03:51
So here's the thing. It sounds like a simple question.
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所以，这就是事实。这听起来是很简单的问题。
03:53
Is CO2 produced by man's activities
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是人类活动制造的二氧化碳
03:56
causing the planet to warm up?
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造成了全球变暖么？
03:58
But to answer that question,
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要回答这个问题，
04:00
to make a clear attribution to carbon dioxide,
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并对二氧化碳进行一个明确的归属，
04:03
you have to know something about
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你还必须了解一些
04:05
all of these other agents of change.
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造成变化的所有这些其它的媒介。
04:07
But the fact is we do know a lot about all of those things.
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不过事实上，就这些而言我们懂得够多了。
04:10
You know, thousands of scientists
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大家知道，数以千计的科学家
04:12
have been working on understanding
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致力于研究
04:14
all of these man-made causes
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所有这些人为因素
04:16
and the natural causes.
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和自然因素。
04:18
And we've got it worked out, and we can say,
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我们也已经搞明白了，并且可以说，
04:21
"Yes, CO2 is causing the planet to warm up now."
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“是的，目前二氧化碳正在导致这个星球变暖。”
04:25
Now, we have many ways to study natural variability.
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目前我们有很多办法来研究自然环境的变化。
04:28
I'll show you a few examples of this now.
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下面我将给大家展示一些案例。
04:30
This is the ship that I spent the last three months on in the Antarctic.
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这是一艘船，我近三个月来都乘着它待在南极地带。
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It's a scientific drilling vessel.
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这是一艘科学钻探船。
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We go out for months at a time and drill into the sea bed
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我们不时地会乘它外出几个月，到海床上
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to recover sediments
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钻探，回收沉积物，
04:41
that tell us stories of climate change, right.
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就是那些能告诉我们气候变化的沉积物，是的。
04:44
Like one of the ways to understand our greenhouse future
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要了解我们的“温室未来”的方法之一
04:47
is to drill down in time
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就是及时钻探到
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to the last period
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二氧化碳浓度是现在两倍
04:51
where we had CO2 double what it is today.
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的最近的那个年代。
04:53
And so that's what we've done with this ship.
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那么，这就是我们用这条船做的事情。
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This was -- this is south of the Antarctic Circle.
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这曾是——这是南极圈的南面。
04:58
It looks downright tropical there.
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它看起来简直就是热带。
05:00
One day where we had calm seas and sun,
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有一天大海很平静，阳光也很温和，
05:03
which was the reason I could get off the ship.
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这也是我为什么能够下船的原因。
05:05
Most of the time it looked like this.
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大多数时间它都像这个样子。
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We had a waves up to 50 ft.
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海浪高达50英尺，
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and winds averaging
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大多数航程
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about 40 knots for most of the voyage
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能达到40海里
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and up to 70 or 80 knots.
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甚至高达70到80海里。
05:16
So that trip just ended,
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所以那趟旅行就结束了，
05:18
and I can't show you too many results from that right now,
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眼下我也不能给大家展示太多结果，
05:20
but we'll go back one more year,
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不过我们会在一年多后回来，
05:22
to another drilling expedition I've been involved in.
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到我参与的另一个钻探旅程中。
05:25
This was led by Ross Powell and Tim Naish.
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这个团队由罗斯鲍威尔和蒂姆奈什领导。
05:28
It's the ANDRILL project.
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这是ANDRILL项目。
05:30
And we made the very first bore hole
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然后我们在世界上最大的浮冰层上
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through the largest floating ice shelf on the planet.
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打出了第一个钻孔。
05:34
This is a crazy thing, this big drill rig wrapped in a blanket
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这是一件疯狂的事情，这个大型钻机裹着一条毯子
05:37
to keep everybody warm,
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用来给所有人保暖，
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drilling at temperatures of minus 40.
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而我们在零下40度进行钻探。
05:41
And we drilled in the Ross Sea.
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我们在罗斯海钻探过。
05:43
That's the Ross Sea Ice Shelf on the right there.
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那就是罗斯海冰架。
05:46
So, this huge floating ice shelf
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所以，这个相当于阿拉斯加大小的
05:48
the size of Alaska
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巨型浮冰层
05:50
comes from West Antarctica.
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来自于西南极洲。
05:52
Now, West Antarctica is the part of the continent
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西南极洲就是南极洲的一部分，
05:55
where the ice is grounded on sea floor
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这部分的冰层着陆在深达2000米
05:57
as much as 2,000 meters deep.
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的海床上面。
06:00
So that ice sheet is partly floating,
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因此这块冰层一部分是浮动的，
06:02
and it's exposed to the ocean, to the ocean heat.
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而且它暴露在海洋中，接受着海洋热能。
06:06
This is the part of Antarctica that we worry about.
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这就是我们所担心的那部分南极洲。
06:08
Because it's partly floating, you can imagine,
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因为它一部分是浮动的，你能够想像，
06:10
is sea level rises a little bit,
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海平面上升一点，
06:12
the ice lifts off the bed, and then it can break off and float north.
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这块冰就脱离海床了，然后它就会碎裂，飘向北方。
06:15
When that ice melts, sea level rises by six meters.
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当这块冰融化，海平面会上升6米。
06:19
So we drill back in time to see how often that's happened,
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因此我们进行“回溯”钻探，看看这种事情多久发生一次，
06:22
and exactly how fast that ice can melt.
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以及冰层融化的有多快。
06:25
Here's the cartoon on the left there.
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左边是动画。
06:28
We drilled through a hundred meters of floating ice shelf
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我们钻入了浮冰层一百米，
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then through 900 meters of water
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然后通过了900米的水层，
06:33
and then 1,300 meters into the sea floor.
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然后到达1300米进入海床。
06:36
So it's the deepest geological bore hole ever drilled.
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因此这是有史以来钻探的最深的地质钻孔。
06:39
It took about 10 years to put this project together.
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营建这个工程花了大约10年左右。
06:42
And here's what we found.
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这就是我们所发现的。
06:44
Now, there's 40 scientists working on this project,
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目前有40位科学家为这个项目忙碌，
06:46
and people are doing all kinds of really complicated
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他们在开展一切真正复杂
06:48
and expensive analyses.
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而且昂贵的分析。
06:51
But it turns out, you know, the thing that told the best story
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不过大家知道，能够把事情解释得最好的
06:54
was this simple visual description.
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往往是这最简单的视觉描述。
06:56
You know, we saw this in the core samples as they came up.
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你要知道，我们在核心样本中自然而然地发现了这些。
06:59
We saw these alternations
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我们在沉积物中看到了
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between sediments that look like this --
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像这样的交替出现的痕迹--
07:03
there's gravel and cobbles in there
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砾石、鹅卵石、
07:05
and a bunch of sand.
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还有一些沙子。
07:07
That's the kind of material in the deep sea.
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这就是在深海中的物质。
07:09
It can only get there if it's carried out by ice.
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这些只能被冰块带到那里。
07:12
So we know there's an ice shelf overhead.
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所以我们知道它上面有冰层。
07:14
And that alternates with a sediment that looks like this.
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然后沉积物就像这样交替出现。
07:17
This is absolutely beautiful stuff.
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这绝对是漂亮的艺术品。
07:19
This sediment is 100 percent made up
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这个沉积物百分之百是由
07:21
of the shells of microscopic plants.
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微型植物的外壳构成的。
07:24
And these plants need sunlight,
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这些植物需要阳光，
07:26
so we know when we find that sediment
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所以当我们发现这沉积物时，
07:28
there's no ice overhead.
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我们知道原来它上面本没有冰。
07:30
And we saw about 35 alternations
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我们在开放水域和冰层覆盖的水域中
07:32
between open water and ice-covered water,
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看到大约35次这些砾石和
07:35
between gravels and these plant sediments.
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植物沉积物的交替变化。
07:38
So what that means is, what it tells us
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因此这就意味着，它告诉我们
07:41
is that the Ross Sea region, this ice shelf,
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罗斯海地区，这块冰盖，
07:44
melted back and formed anew
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融化后再重生了大约
07:46
about 35 times.
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35次。
07:48
And this is in the past four million years.
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这些发生于近400万年。
07:52
This was completely unexpected.
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这完全出人意料。
07:54
Nobody imagined that the West Antarctic Ice Sheet
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没人能想象得到西南极洲冰盖
07:56
was this dynamic.
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曾经如此活跃。
07:58
In fact, the lore for many years has been,
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实际上，我们多年的认知就是，
08:01
"The ice formed many tens of millions of years ago,
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“冰层在百万甚至千万年前就形成了，
08:03
and it's been there ever since."
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它从一开始就在那里。”
08:05
And now we know that in our recent past
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现在我们知道了，在近代
08:07
it melted back and formed again,
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它融化并且重生，
08:09
and sea level went up and down, six meters at a time.
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海平面时起时落，一次落差达6米。
08:12
What caused it?
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什么原因导致其发生？
08:14
Well, we're pretty sure that it's very small changes
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呃，我们非常确信到达南极洲的太阳光量
08:16
in the amount of sunlight reaching Antarctica,
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变化非常小，
08:19
just caused by natural changes in the orbit of the Earth.
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它由地球轨道上的自然环境变化引发。
08:22
But here's the key thing:
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不过关键点是：
08:24
you know, the other thing we found out
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你要知道，我们发现了另外一件事，
08:26
is that the ice sheet passed a threshold,
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那就是这个冰盖曾经越过一道槛，
08:28
that the planet warmed up enough --
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这个星球曾暖到一定程度——
08:30
and the number's about one degree to one and a half degrees Centigrade --
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温度上升了1度到1度半——
08:32
the planet warmed up enough that it became ...
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这星球变暖到它变得。。。
08:35
that ice sheet became very dynamic
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变暖到冰层变得非常活跃
08:37
and was very easily melted.
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非常容易融化。
08:39
And you know what?
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然后你们知道么？
08:41
We've actually changed the temperature in the last century
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我们上个世纪实际的温度变化
08:43
just the right amount.
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正好是那个量。
08:45
So many of us are convinced now
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所以我们中的很多人确信
08:48
that West Antarctica, the West Antarctic Ice Sheet, is starting to melt.
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现在西南极洲，西南极洲冰盖正在开始融化。
08:51
We do expect to see a sea-level rise
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我们相信能够看到海平面上升，
08:54
on the order of one to two meters by the end of this century.
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这个世纪末将上升1到2米。
08:57
And it could be larger than that.
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而且上升幅度有可能更大。
09:00
This is a serious consequence
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对于像基里巴斯这样的国家来说，
09:02
for nations like Kiribati,
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这是非常严重的后果。
09:04
you know, where the average elevation
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你要知道，它的平均海拔
09:06
is about a little over a meter above sea level.
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只是1米多一点点。
09:08
Okay, the second story takes place here in Galapagos.
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好的，第二个故事发生在这里，加拉帕戈斯群岛。
09:11
This is a bleached coral,
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这是一块漂白的珊瑚，
09:13
coral that died during the 1982-'83 El Nino.
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一块死于1982-83年厄尔尼诺现象的珊瑚礁。
09:16
This is from Champion Island.
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这个来自冠军群岛。
09:18
It's about a meter tall Pavona clavus colony.
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这是海拔约1米高的Pavona clavus珊瑚礁。
09:21
And it's covered with algae. That's what happens.
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它已被藻类所覆盖。这就是目前所发生的。
09:24
When these things die,
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当这些生命凋谢，
09:26
immediately, organisms come in
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马上有机体会进入，
09:28
and encrust and live on that dead surface.
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并且覆盖它们，并在其表面生存。
09:31
And so, when a coral colony is killed
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那么，当一块珊瑚礁
09:33
by an El Nino event,
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被一次厄尔尼诺扼杀，
09:35
it leaves this indelible record.
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就留下了不可磨灭的印记。
09:37
You can go then and study corals
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你可以去研究珊瑚，
09:39
and figure out how often do you see this.
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搞明白这样的事情发生的有多频繁。
09:41
So one of the things thought of in the '80s
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上世纪80年代有一次（厄尔尼诺）
09:43
was to go back and take cores
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我们返回加拉帕戈斯群岛
09:45
of coral heads throughout the Galapagos
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并从那里的珊瑚礁顶采集珊瑚的核心，
09:47
and find out how often was there a devastating event.
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以便找出这样破坏性事件发生的有多频繁。
09:50
And just so you know, 1982-'83,
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正如你所知道的，1982到83年
09:53
that El Nino killed 95 percent
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那次厄尔尼诺杀死了加拉帕戈斯群岛
09:55
of all the corals here in Galapagos.
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百分之九十五的珊瑚。
09:58
Then there was similar mortality in '97-'98.
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随后，97到98年（那次厄尔尼诺）的死亡率也跟这次很接近。
10:01
And what we found
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在“回溯”钻探了400年
10:03
after drilling back in time two to 400 years
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后我们发现，
10:05
was that these were unique events.
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这些都是很独特的事件。
10:07
We saw no other mass mortality events.
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我们以前没有见过这么大规模的死亡事件。
10:10
So these events in our recent past really are unique.
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因此近年来这些事件真是非常特别。
10:13
So they're either just truly monster El Ninos,
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因此他们要么不仅仅真的是“怪兽”厄尔尼诺，
10:15
or they're just very strong El Ninos
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要么就是在全球变暖背景下发生的
10:17
that occurred against a backdrop of global warming.
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非常强大的厄尔尼诺。
10:21
Either case, it's bad news
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无论是哪种情况，对于加拉帕戈斯群岛
10:23
for the corals of the Galapagos Islands.
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的珊瑚来说都是个噩耗。
10:27
Here's how we sample the corals.
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这就是我们如何在珊瑚礁取样的。
10:29
This is actually Easter Island. Look at this monster.
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这实际上是东部群岛。看看这个怪物。
10:32
This coral is eight meters tall, right.
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这块珊瑚有8米高。
10:35
And it been growing for about 600 years.
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它已经生长了大约600年。
10:37
Now, Sylvia Earle turned me on to this exact same coral.
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现在，西尔维娅厄尔给我展示的同样是这块珊瑚。
10:40
And she was diving here with John Lauret -- I think it was 1994 --
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她与约翰劳瑞特在这里潜水——我想是1994年——
10:43
and collected a little nugget and sent it to me.
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并且采集了这个块状物并把它寄给了我。
10:45
And we started working on it,
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然后我们开始对它展开研究，
10:47
and we figured out we could tell the temperature of the ancient ocean
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我们明白我们可以通过分析这样一块珊瑚
10:49
from analyzing a coral like this.
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来得知古代海洋的温度。
10:52
So we have a diamond drill.
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我们有一个钻石钻头。
10:54
We're not killing the colony; we're taking a small core sample out of the top.
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我们没有杀死这块珊瑚礁；我们只是从它顶部采集了一个内核样本。
10:57
The core comes up as these cylindrical tubes of limestone.
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珊瑚的内核就像这些石灰石圆柱管。
11:00
And that material then we take back to the lab and analyze it.
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我们把这块材料拿回实验室并对它进行分析。
11:04
You can see some of the coral cores there on the right.
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你们可以在右边看到一些珊瑚内核。
11:07
So we've done that all over the Eastern Pacific.
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所以我们踏遍了东太平洋进行这种研究。
11:09
We're starting to do it in the Western Pacific as well.
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同样我们也正在西太平洋开展研究。
11:12
I'll take you back here to the Galapagos Islands.
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下面我们回到这里，加拉帕戈斯群岛。
11:14
And we've been working at this fascinating uplift here in Urbina Bay.
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我们一直在这个乌尔维纳湾迷人的“高地”工作。
11:17
That the place where,
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这个地方
11:19
during an earthquake in 1954,
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1954年发生过地震，
11:21
this marine terrace was lifted up
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这块海洋中的平台从海中
11:23
out of the ocean very quickly,
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抬升得很快，
11:26
and it was lifted up about six to seven meters.
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目前它已经上升了约6到7米。
11:29
And so now you can walk through a coral reef without getting wet.
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因此现在你可以不湿鞋就可以走遍整块珊瑚礁。
11:32
If you go on the ground there, it looks like this,
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如果你登上那块地面，就像这个，
11:34
and this is the grandaddy coral.
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这是一块祖父辈的珊瑚。
11:36
It's 11 meters in diameter,
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它直径有11米，
11:38
and we know that it started growing
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我们知道它从1584年
11:40
in the year 1584.
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就开始生长。
11:42
Imagine that.
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想象一下。
11:44
And that coral was growing happily in those shallow waters,
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这块珊瑚在浅海中快乐地成长，
11:47
until 1954, when the earthquake happened.
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直到1954年，发生了地震。
11:50
Now the reason we know it's 1584
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我们知道它从1584年开始生长的原因
11:52
is that these corals have growth bands.
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就是这些珊瑚拥有的生长带。
11:54
When you cut them, slice those cores in half and x-ray them,
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当你切开这些珊瑚内核，把半面切片放在X光下，
11:57
you see these light and dark bands.
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你会看到这些明和暗的带子。
11:59
Each one of those is a year.
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每一条都代表一年。
12:01
We know these corals grow about a centimeter and a half a year.
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我们知道这些珊瑚一年大约生长1.5厘米。
12:03
And we just count on down to the bottom.
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于是我们就从上数到下。
12:06
Then their other attribute is
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它们其他的属性还包括
12:08
that they have this great chemistry.
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它们拥有这样神奇的化学构成。
12:10
We can analyze the carbonate
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我们可以分析构成
12:12
that makes up the coral,
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珊瑚礁的碳酸盐，
12:14
and there's a whole bunch of things we can do.
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此外还有其他一堆事情可以做。
12:16
But in this case, we measured the different isotopes of oxygen.
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但在这个案例中，我们测量了不同的氧同位素。
12:19
Their ratio tells us the water temperature.
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它们的比例能告诉我们水温。
12:21
In this example here,
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在这个例子中，
12:23
we had monitored this reef in Galapagos
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我们用温度记录仪监测了加拉帕戈斯群岛
12:25
with temperature recorders,
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这块珊瑚礁。
12:27
so we know the temperature of the water the coral's growing in.
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所以我们就知道了珊瑚生长水域的温度。
12:30
Then after we harvest a coral, we measure this ratio,
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随后我们采集了一块珊瑚，并测量了这个比例，
12:33
and now you can see, those curves match perfectly.
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下面你就能看到，那些曲线完美吻合。
12:36
In this case, at these islands,
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在这个案例中，在这些群岛，
12:38
you know, corals
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你知道，这些珊瑚
12:40
are instrumental-quality recorders of change in the water.
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是水中温度变化的记录仪，如同机器般精准。
12:43
And of course, our thermometers
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当然，我们的温度计
12:45
only take us back 50 years or so here.
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只能让我们回溯50年左右。
12:47
The coral can take us back
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这些珊瑚却可以把我们带回
12:49
hundreds and thousands of years.
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成百上千年以前。
12:51
So, what we do:
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所以，这就是我们所做的：
12:53
we've merged a lot of different data sets.
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我们汇集了很多不同的数据集。
12:56
It's not just my group; there's maybe 30 groups worldwide doing this.
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不仅仅我们这个团队；还有全世界可能30个从事这项工作的团队。
12:59
But we get these instrumental- and near-instrumental-quality records
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我们取得这些仪器般精准或接近仪器般精准的、
13:02
of temperature change that go back hundreds of years,
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回溯了上百年的温度变化记录，
13:04
and we put them together.
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并把它们汇总起来。
13:06
Here's a synthetic diagram.
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这是一张合成图。
13:08
There's a whole family of curves here.
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这里有全套的数据曲线。
13:10
But what's happening: we're looking at the last thousand years
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发生了什么？我们看到的是这个星球近百年以来
13:13
of temperature on the planet.
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的温度变化。
13:15
And there's five or six different compilations there,
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这儿有5到6种不同的破译方式。
13:17
But each one of those compilations reflects input
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每一种方式都反映了从珊瑚上得来的
13:20
from hundreds of these kinds of records from corals.
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数百条记录的输入。
13:23
We do similar things with ice cores.
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我们对冰核也采取这样的做法。
13:26
We work with tree rings.
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我们对树木年轮也采取这样的做法。
13:28
And that's how we discover
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我们就是这样发现
13:30
what is truly natural
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什么才是真正的自然环境
13:32
and how different is the last century, right?
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以及上个世纪又是多么与众不同，对么？
13:35
And I chose this one
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我选择了这个
13:37
because it's complicated and messy looking, right.
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因为它很复杂而且很难理清楚。
13:40
This is as messy as it gets.
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就像它本身一样毫无头绪。
13:42
You can see there's some signals there.
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你可以看到那里有一些信号。
13:45
Some of the records
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某些记录显示
13:47
show lower temperatures than others.
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它们的温度要比其他的低。
13:49
Some of them show greater variability.
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某些显示了更显著的变化。
13:52
But they all tell us
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不过它们都告诉了我们
13:54
what the natural variability is.
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自然环境的变化是什么样的。
13:56
Some of them are from the northern hemisphere;
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某些是从北半球的大气层中来的；
13:58
some are from the entire globe.
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某些是从世界各地来的。
14:00
But here's what we can say:
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我能说的是：
14:02
what's natural in the last thousand years is that the planet was cooling down.
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近千年以来这个星球正在不断变冷，这才是自然的环境。
14:05
It was cooling down
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它从1900年左右就
14:07
until about 1900 or so.
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开始冷却了。
14:09
And there is natural variability
347
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自然环境的变化是由
14:11
caused by the Sun, caused by El Ninos.
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太阳、厄尔尼诺造成的。
14:14
A century-scale, decadal-scale variability,
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一个世纪范围内，几十年范围内的变化，
14:16
and we know the magnitude;
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我们知道这个幅度；
14:18
it's about two-tenths to four-tenths of a degree Centigrade.
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它约为五分之一到五分之二摄氏度。
14:21
But then at the very end is where
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随后，我们就到了记录的最后，
14:23
we have the instrumental record in black.
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那条记录是黑色的。
14:25
And there's the temperature up there in 2009.
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这是2009年的温度。
14:28
You know, we've warmed the globe
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你要知道，上个世纪以来，我们已经
14:30
about a degree Centigrade in the last century,
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让全球上升了约一摄氏度。
14:33
and there's nothing
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在我们的自然环境的记录中
14:35
in the natural part of that record
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从没有过这样一个时代
14:37
that resembles what we've seen in the last century.
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能够与上个世纪相提并论。
14:39
You know, that's the strength of our argument,
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你要知道，这就是我们的论据的力量，
14:41
that we are doing something that's truly different.
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也就是说，我们确实改变了一些事情。
14:45
So I'll close with a short discussion
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所以我就以一个海洋酸化
14:48
of ocean acidification.
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的简短讨论来结束（今天的演讲）。
14:51
I like it as a component of global change to talk about,
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我希望将它作为全球变化的一个组成部分来讨论，
14:54
because, even if you are a hard-bitten global warming skeptic,
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因为，即使你是一个固执的全球变暖怀疑论者，
14:58
and I talk to that community fairly often,
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（我也经常跟那种团体进行沟通）
15:00
you cannot deny
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你也不能否认
15:02
the simple physics
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二氧化碳正在被海洋
15:04
of CO2 dissolving in the ocean.
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吸收这个简单的事实。
15:07
You know, we're pumping out lots of CO2 into the atmosphere,
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你要知道，我们通过化石燃料，通过水泥的生产
15:10
from fossil fuels, from cement production.
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向大气层排放了很多二氧化碳。
15:13
Right now, about a third of that carbon dioxide
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眼下，大约三分之一的二氧化碳
15:15
is dissolving straight into the sea, right?
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直接被海洋所吸收，对么？
15:17
And as it does so,
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结果，
15:19
it makes the ocean more acidic.
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这就让海洋的酸度更强。
15:22
So, you cannot argue with that.
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所以你不必就此展开争论。
15:24
That is what's happening right now,
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那就是现在正在发生的事情，
15:26
and it's a very different issue
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它与全球变暖是非常
15:28
than the global warming issue.
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不同的两件事情。
15:30
It has many consequences.
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它会导致很多后果。
15:32
There's consequences for carbonate organisms.
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对于碳酸盐的有机体来讲有很多不良后果。
15:35
There are many organisms
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许多生物——包括植物和动物
15:37
that build their shells out of calcium carbonate --
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用碳酸钙来构筑
15:39
plants and animals both.
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它们的外壳。
15:42
The main framework material of coral reefs
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珊瑚礁的主要构筑材料
15:44
is calcium carbonate.
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也是碳酸钙。
15:46
That material is more soluble
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这种材料在酸性液体中
15:48
in acidic fluid.
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更容易溶解。
15:51
So one of the things we're seeing
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所以我们将看到的是
15:53
is organisms are having
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生物将花费
15:55
to spend more metabolic energy
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更多的代谢能量
15:57
to build and maintain their shells.
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来构筑并维持他们的外壳。
15:59
At some point, as this transience,
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在某种程度上，此刻，
16:01
as this CO2 uptake in the ocean continues,
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若海洋持续吸收二氧化碳，
16:04
that material's actually going to start to dissolve.
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那么这些物质实际上将开始溶解。
16:06
And on coral reefs,
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在珊瑚礁上面，
16:08
where some of the main framework organisms disappear,
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若那些形成主要构架的生物消失了，
16:11
we will see a major loss
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我们就会痛失
16:13
of marine biodiversity.
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海洋的生态多样性。
16:15
But it's not just the carbonate producers that are affected.
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不过不仅仅是碳酸盐制造者会受到影响。
16:18
There's many physiological processes
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还有许多生理进程
16:21
that are influenced by the acidity of the ocean.
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会受到海洋酸度的影响。
16:24
So many reactions involving enzymes and proteins
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许多酶和蛋白质参与的反应
16:27
are sensitive to the acid content of the ocean.
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对海洋的酸度非常敏感。
16:30
So, all of these things --
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因此，所有这些——
16:32
greater metabolic demands,
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更旺盛的代谢需求，
16:34
reduced reproductive success,
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降低的繁殖成功率，
16:36
changes in respiration and metabolism.
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呼吸作用和代谢过程的变化。
16:39
You know, these are things that we have good physiological reasons
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你要知道，在受到目前片刻的影响后，
16:42
to expect to see stressed
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我们能找到足够充分的生理原因
16:44
caused by this transience.
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来预测到这些变化。
16:46
So we figured out some pretty interesting ways
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因此我们发现了一些非常有趣的方法
16:48
to track CO2 levels in the atmosphere,
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来跟踪数百万年前大气层中
16:51
going back millions of years.
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的二氧化碳水平。
16:53
We used to do it just with ice cores,
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我们过去仅仅使用冰核，
16:55
but in this case, we're going back 20 million years.
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但是在这个案例中，我们要回溯2000万年。
16:58
And we take samples of the sediment,
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于是我们就采集了海底沉积物的样本，
17:00
and it tells us the CO2 level of the ocean,
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它告诉我们海洋中二氧化碳的浓度
17:03
and therefore the CO2 level of the atmosphere.
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从而我们也知道了大气中二氧化碳的浓度。
17:05
And here's the thing:
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接下来的事情就是
17:07
you have to go back about 15 million years
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我们必须回溯大概1500万年
17:09
to find a time when CO2 levels
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去寻找一个二氧化碳浓度跟
17:12
were about what they are today.
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今天相近的年代。
17:14
You have to go back about 30 million years
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我们必须回溯大约3000万年
17:16
to find a time when CO2 levels
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去寻找一个二氧化碳浓度相当于
17:18
were double what they are today.
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今天的两倍的年代。
17:20
Now, what that means is
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现在，这意味着
17:22
that all of the organisms that live in the sea
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所有生活在海洋中的生物都
17:24
have evolved in this chemostatted ocean,
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在这个恒定的海洋中进化，
17:27
with CO2 levels lower than they are today.
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而其中的二氧化碳浓度低于现在的浓度。
17:30
That's the reason that they're not able to respond or adapt
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这也是他们为什么没有能力去应对或适应
17:33
to this rapid acidification
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海洋的快速酸化。
17:36
that's going on right now.
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目前这正在发生。
17:38
So, Charlie Veron
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所以，查理弗隆
17:40
came up with this statement last year:
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去年带着这个课题来到这里。
17:42
"The prospect of ocean acidification
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“海洋酸化的前景
17:44
may well be the most serious
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可能是目前人类活动造成的
17:46
of all of the predicted outcomes
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二氧化碳排放所导致的所有可预见的
17:48
of anthropogenic CO2 release."
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后果中最严重的一种。”
17:51
And I think that may very well be true,
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我认为他说的很靠谱，
17:54
so I'll close with this.
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所以我会一直密切关注它。
17:56
You know, we do need the protected areas, absolutely,
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你要知道，我们绝对需要一些受保护的领域，
17:59
but for the sake of the oceans,
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但是看在海洋的份上，
18:01
we have to cap or limit CO2 emissions
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我们必须马上限制
18:03
as soon as possible.
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二氧化碳的排放。
18:05
Thank you very much.
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非常感谢！
18:07
(Applause)
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（掌声）
ABOUT THE SPEAKER
Rob Dunbar - Oceanographer, biogeochemistRob Dunbar looks deeply at ancient corals and sediments to study how the climate and the oceans have shifted over the past 50 to 12,000 years -- and how the Antarctic ecosystem is changing right now.
Why you should listen
Rob Dunbar's research looks at the earth and ocean as an interconnected system over time. With his group at Stanford, he makes high-resolution studies of climate change over the past 50 to 12,000 years.
Where does 12,000-year-old climate data come from? It's locked in the skeletons of ancient corals from the tropics and the deep sea, and buried in sediments from lakes and other marine environments. His lab measures the chemical and isotopic makeup of these materials, and looks at how they've changed in response to changes in the solar and carbon cycles.
Dunbar's also studying the reverse equation -- how climate change is affecting a modern environment right now. He's working in the Ross Sea of Antarctica with the ANDRILL project to study the ocean's ability to take up carbon, drilling for ice cores to uncover the history of the climate of Antarctica.
Rob Dunbar | Speaker | TED.com