WEBVTT

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Do you ever think about how important
the oceans are in our daily lives?

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The oceans cover two-thirds of our planet.

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They provide half the oxygen we breathe.

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They moderate our climate.

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And they provide jobs
and medicine and food

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including 20 percent of protein
to feed the entire world population.

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People used to think
that the oceans were so vast

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that they wouldn't be affected
by human activities.

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Well today I'm going to tell you
about a serious reality

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that is changing our oceans
called ocean acidification,

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or the evil twin of climate change.

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Did you know that the oceans have absorbed
25 percent of all of the carbon dioxide

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that we have emitted to the atmosphere?

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Now this is just another great service
provided by the oceans

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since carbon dioxide
is one of the greenhouse gases

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that's causing climate change.

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But as we keep pumping
more and more and more

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carbon dioxide into the atmosphere

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more is dissolving into the oceans.

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And this is what's changing
our ocean chemistry.

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When carbon dioxide dissolves in seawater,

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it undergoes a number
of chemical reactions.

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Now lucky for you,

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I don't have time to get into
the details of the chemistry for today.

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But I'll tell you as more
carbon dioxide enters the ocean,

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the seawater pH goes down.

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And this basically means that there
is an increase in ocean acidity.

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And this whole process
is called ocean acidification.

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And it's happening
alongside climate change.

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Scientists have been monitoring
ocean acidification for over two decades.

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This figure is an important
time series in Hawaii,

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and the top line shows steadily increasing
concentrations of carbon dioxide,

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or CO2 gas, in the atmosphere.

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And this is directly as a result
of human activities.

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The line underneath shows the increasing
concentrations of carbon dioxide

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that is dissolved
in the surface of the ocean

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which you can see is increasing
at the same rate

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as carbon dioxide in the atmosphere
since measurements began.

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The line on the bottom shows
then shows the change in chemistry.

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As more carbon dioxide
has entered the ocean,

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the seawater pH has gone down,

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which basically means there has been
an increase in ocean acidity.

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Now in Ireland, scientists are also
monitoring ocean acidification --

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scientists at the Marine
Institute and NUI Galway.

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And we, too, are seeing
acidification at the same rate

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as these main ocean time-series
sites around the world.

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So it's happening right at our doorstep.

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Now I'd like to give you an example
of just how we collect our data

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to monitor a changing ocean.

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Firstly we collect a lot of our samples
in the middle of winter.

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So as you can imagine,
in the North Atlantic

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we get hit with some seriously
stormy conditions --

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so not for any of you
who get a little motion sickness,

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but we are collecting
some very valuable data.

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So we lower this instrument
over the side of the ship,

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and there are sensors
that are mounted on the bottom

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that can tell us information about
the surrounding water,

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such as temperature
or dissolved oxygen.

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And then we can collect our seawater
samples in these large bottles.

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So we start at the bottom,
which can be over four kilometers deep

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just off our continental shelf,

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and we take samples at regular intervals
right up to the surface.

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We take the seawater back on the deck,

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and then we can either
analyze them on the ship

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or back in the laboratory
for the different chemicals parameters.

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But why should we care?

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How is ocean acidification
going to affect all of us?

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Well, here are the worrying facts.

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There has already been an increase
in ocean acidity of 26 percent

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since pre-industrial times,
which is directly due to human activities.

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Unless we can start slowing down
our carbon dioxide emissions,

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we're expecting an increase
in ocean acidity of 170 percent

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by the end of this century.

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I mean this is within
our children's lifetime.

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This rate of acidification
is 10 times faster

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than any acidification in our oceans
for over 55 million years.

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So our marine life have never,
ever experienced

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such a fast rate of change before.

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So we literally could not know
how they're going to cope.

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Now there was a natural acidification
event millions of years ago,

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which was much slower
than what we're seeing today.

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And this coincided with a mass extinction
of many marine species.

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So is that what we're headed for?

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Well, maybe.

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Studies are showing
some species are actually doing quite well

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but many are showing a negative response.

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One of the big concerns is
as ocean acidity increases,

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the concentration of carbonate
ions in seawater decrease.

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Now these ions are basically
the building blocks

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for many marine species
to make their shells,

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for example crabs or mussels, oysters.

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Another example are corals.

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They also need these carbonate
ions in seawater

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to make their coral structure
in order to build coral reefs.

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As ocean acidity increases

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and the concentration
of carbonate ions decrease,

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these species first find it more difficult
to make their shells.

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And at even even lower levels,
they can actually begin to dissolve.

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This here is a pteropod,
it's called a sea butterfly.

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And it's an important food source
in the ocean for many species,

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from krill to salmon right up to whales.

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The shell of the pteropod
was placed into seawater

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at a pH that we're expecting
by the end of this century.

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After only 45 days
at this very realistic pH,

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you can see the shell
has almost completely dissolved.

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So ocean acidification could affect
right up through the food chain --

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and right onto our dinner plates.

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I mean who here
likes shellfish? Or salmon?

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Or many other fish species

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whose food source
in the ocean could be affected?

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These are cold-water corals.

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And did you know we actually have
cold-water corals in Irish waters,

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just off our continental shelf?

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And they support rich biodiversity,
including some very important fisheries.

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It's projected that
by the end of this century,

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70 percent of all known cold-water corals
in the entire ocean

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will be surrounded by seawater
that is dissolving their coral structure.

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The last example I have
are these healthy tropical corals.

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They were placed in seawater at a pH
we're expecting by the year 2100.

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After six months, the coral
has almost completely dissolved.

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Now coral reefs support

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25 percent of all marine life
in the entire ocean.

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All marine life.

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So you can see: ocean
acidification is a global threat.

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I have an eight-month-old baby boy.

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Unless we start now to slow this down,

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I dread to think what our oceans
will look like when he's a grown man.

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We will see acidification.

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We have already put too much
carbon dioxide into the atmosphere.

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But we can slow this down.

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We can prevent the worst-case scenario.

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The only way of doing that

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is by reducing our
carbon dioxide emissions.

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This is important for both you and I,
for industry, for governments.

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We need to work together,
slow down global warming

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slow down ocean acidification

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and help to maintain a healthy ocean
and a healthy planet

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for our generation
and for generations to come.

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(Applause)