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This is something some
of you may have seen.

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The data here in
from the '50s is

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from the Mauna Loa measurements,
the top of a volcano.

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And this is CO2 concentration,
parts per million

5
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in the atmosphere.

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But if you dig into the ice--

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we're going to be
doing a lot of that

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here in Boston over
the next three months.

9
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But if you dig deeper into
the ice, in the cores,

10
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you go back in time, and
it's a beautiful thing.

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The ice as you go down
is ancient atmosphere.

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That's cool-- because
there's little bubbles.

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Remember, we talked
about the half life

14
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of carbon-14 that's trapped from
a living thing breathing it in.

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Well, you can trap
directly the little bubbles

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of atmosphere in the ice,
and that's what happens.

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And that's why we know what
CO2 levels-- we're going back

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almost a million years here.

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It's 800,000 years of data.

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And this is a graph that I
think many of you have seen.

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It's going up, a lot.

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And here it is.

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Now, this is just
zooming in on the last 50

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or so-- this is just the
data, the Mauna Loa data.

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And The reason is
because here we also

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have another kind of data.

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So there's a lot of
attention paid on CO2,

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and there should be.

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There is a lot less
attention paid to what

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that is doing to our oceans.

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And this is a reaction that
we will talk about more when

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we talk about acidification.

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So when we talk about
acids and bases,

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which is coming up later--

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later being Wednesday
and next week--

36
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we'll talk more about this.

37
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But I just want to
tell you that when

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you have CO2 in the
atmosphere going up,

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then you also have CO2
in the ocean going up.

40
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So the CO2 in the ocean--

41
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the CO2 in the atmosphere is
getting absorbed by the ocean.

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So what?

43
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No, it's a lot of what,
because what happens

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is the CO2 in the ocean--

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the more CO2 in the ocean--

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is making the ocean more acidic.

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So if you just write
this number down--

48
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because it's so astonishing.

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Past 200 years, the ocean
has become 30% more acidic.

50
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Now that is the fastest-known
change in the ocean chemistry

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in 50 million years.

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That's a big and
very sudden change.

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So the ocean is absorbing about
22 million tons per day of CO2.

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And that number is going up.

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Why does that matter?

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Maybe it will do
to the oceans what

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it's doing to the atmosphere and
making things a little warmer.

58
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No, it's doing more,
because when it acidifies,

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then it has a direct
impact on things

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like this, which is a pteropod.

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You look at the food
chain of the ocean-- there

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are three things at the bottom.

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That's one of them.

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I mean, there's plants.

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There's photosynthesis.

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And then there's the
bottom of the food chain.

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Now you know what's
going to happen

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when the bottom of the
food chain disappears.

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This is one of the
main kinds of animals

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that lives at the
bottom of ocean

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because they've got these very
small calcium carbonate shells.

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If you make the
ocean just a little

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more acidic, like we're doing,
those shells don't survive,

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and those animals don't survive.

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So that's what
happens to a pteropod.

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At the rate we're going--

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like decades of time from
now-- that's what happens.

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So what you have
in your goodie bag

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is a way to see this a
little bit more accelerated.

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So here's your goodie bag.

81
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So I wanted you to--

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I wanted you to see what's
happening in the ocean,

83
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and you have now the
tools to do that.

84
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So in your goodie bag,
you've got citric powder.

85
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Imagine you take a lot of
limes, and you squeeze them,

86
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and then you dry it all out.

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And that's what you got--

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citric acid.

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Now you're going to mix that
with water to change the ph.

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And you're going to
dissolve this powder.

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That's the topic of today's
lecture-- dissolution

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and equilibrium.

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So you're going to
mix that into water,

94
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and you've got a scale
from a previous goodie bag.

95
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So my hope is that you've been
using that on a daily basis.

96
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You take it with you places,
and you can use that again here.

97
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And you'll need that,
because I want you to see

98
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how these shells dissolve.

99
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And if you lower
the acidity more--

100
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we don't want to wait 40--

101
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well, you can wait
45 days, but I

102
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want you to be able to do
these experiments in minutes.

103
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So we're going to go a little
lower in acidity, in ph,

104
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but you're going to
get the same result.

105
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You're going to
dissolve these shells.