ago sorry when I was a child I was 10
years old living in rural Canada and my
parents put my brother and I into our
family station wagon and we drove the 24
hours down to the coast of Florida when
we arrived and I saw the ocean for the
first time I saw its vastness we opened
the car door and I smelt the salty sea
air and when when we went wading into
the waves
we saw the dolphins playing offshore I
knew that in there that I wanted to look
after all the creatures that lived in
the oceans
a decade later I was an undergraduate
major studying in marine biology and
what I learned is that if I wanted to
look after all those plants and animals
I first had to look after their home the
ocean itself now I’m an oceanographer
and I study the health of our oceans and
what I’m seeing in my research and the
research for my colleagues is not great
the oceans aren’t doing very well and
that’s because of carbon the carbon that
we’re putting in the atmosphere that’s
warming the sea water temperatures and
then some of that carbon is dissolving
into the sea water changing the sea
water pH now the oceans are really old
there are over 4 billion years and
they’ve been evolving for a very long
period of time over the entire time
they’ve been around and if we look at
the things that lived in the ocean a
long time ago they look very different
than what lives in the ocean today but
what’s happening now is the rate of
change that’s happening the warming and
the change in sea water pH is happening
faster then it’s happened over the past
several hundred million years and maybe
faster than it’s ever happened and so
we’re changing what’s going to be able
to live in the oceans and in particular
we’re making it hard for organisms that
have a calcium carbonate skeleton so if
you’re a scuba diver or a snorkeler then
maybe tropical corals are familiar sight
to you or maybe you don’t like going in
the ocean water but you like eating
stuff from the ocean shellfish and
oysters
these have a calcium carbonate skeleton
and it’s harder for them to grow in the
oceans today because of us and then as a
scientist what I study it’s a plant is
this like pink thing that you can see
it’s a plant living in the shallow
waters of the ocean on the sea floor
it’s photosynthesizes and it grows a
hard rock like skeleton and this plant
is amazing
because we can use it as a tool to
understand how the oceans have changed
to explain this I’m going to use a plant
that probably most of you are more
familiar with a tree so some trees in
some locations form growth rings and
these growth rings are formed every year
in the trunk of the tree and if you know
when the trunk was cut down or if you
take a piece of the tree you can
actually identify time in the growth of
the trunk and you can count year after
year after year
that that tree was living now some trees
in some locations they respond to
changes in temperature when it’s warmer
they grow more and that growth ring is
actually a little bit wider and when
it’s cooler outside cooler year they
grow less and that growth ring is a
little bit narrower and you can actually
measure the width of each of these
growth rings of that tree was living and
create a record of how temperature
around that tree has changed over the
lifespan of the tree and I do the same
thing in the oceans with my coral and
algae the top layer across the pink
there’s that with a living tissue layer
when the specimen was collected this is
one of our giant specimens you can see
it was about this big when we collected
it and it formed this hard rock like
skeleton of calcium carbonate and when
we section this algae in half we get
growth layers in the skeleton just like
the growth rings in a tree and grows in
this algae changes but what else changes
in the skeleton is the concentration of
an element magnesium so that when the
sea water around the algae is growing is
when the seawater is higher you get more
magnesium and when the sea water is
colder you get less magnesium so you can
actually measure the amount of magnesium
and each growth layer of the skeleton
over the time the algae was growing and
you have a thermometer of seawater
temperature creating a record of how the
temperatures have changed so if this
algae lived for 10 years we know what
temperature was in the oceans a decade
ago or if the algae lived for a hundred
years then we know what temperature was
in the oceans a century ago whoo it’s
really neat
Algie can grow for more than six times
longer than any of us in this room we
have a specimen that’s 646 years old
from the northern Atlantic Ocean each
year putting down that growth layer and
capturing the seawater temperature in
its skeleton and what we’re finding from
these records of ocean temperature is
that temperature has gone up over the
past century
from the oceans from these coral and
algae from trees on land and other
materials in our planet we know
temperature has gone up about one degree
Celsius and based on our understanding
of what causes temperature changing and
how those variables are changing we know
that temperature is going to go up
another degree Celsius by the end of
this century and that is because of
carbon what we’re doing is we are
burning fossil fuels we’re taking carbon
that’s locked in the fossil fuel
reservoir for example is cool we’re
combusting it for energy and as a
product of that we’re putting carbon
dioxide into the atmosphere through the
greenhouse gas effect that’s warming our
planet and our oceans but the other
thing that’s happening is about a third
of that carbon dioxide in the atmosphere
that we’re putting in the carbon death
into the atmosphere is dissolving into
the ocean and this is causing a change
in the chemistry of the ocean the change
that’s happening is when you put more
carbon dioxide dissolving into seawater
it increases the amount of the hydrogen
ion for increasing hydrogen
concentration in the seawater and if you
remember maybe from high school
chemistry or middle school chemistry
that’s pH pH is a measure of the
hydrogen ion we have decreased the pH of
our global oceans by 0.1 pH units over
the past several decades now 0.1 doesn’t
seem like very much but that’s actually
a logarithmic scale and we’ve increased
the relative acidity of the oceans by 25
percent now it happens when you decrease
the water pH when you increase the
amount of the hydrogen ion is more
chemical reactions that decreases the
amount of the carbonate ion and it’s the
hot carbonate ion that the tropical
corals the shellfish and my coral and
algae you
to grow their carbonate skeleton their
calcium carbonate skeleton needs that
carbonate ion and we’re taking away that
carbonate ion from the seawater in our
oceans so my research project right now
as a scientist is to try and understand
what will our oceans look like in the
future one way we can understand that is
to go to areas where this is happening
faster this is a map of the amount of
the carbonate ion in our oceans and what
you can see where the red colors are
there’s less carbonate ion in the higher
latitudes
around the southern ocean around
Antarctica and in the Arctic there’s
less carbonate here because the water is
colder and it’s dissolving more carbon
dioxide so we can use it as a canary in
the gold mine a testing bed to see what
the future oh she’s are going to look
like I was fortunate a couple of years
ago to go up to northern Canada above
the Arctic Circle to do some research in
a very small community we went up there
it was
about a week after the longest day of
the year but it was still winter and
Here I am standing on top of several
hundred meters of ocean I’m standing on
about a metre of sea ice it was starting
to melt and if I had come back a couple
weeks later then I probably would have
been swimming in the ocean at that point
we went during the day searching for the
algae we had identified ahead of time
based on the geology of the area
locations where we thought we would find
the algae underneath the water now it’s
cold I’m a scuba diver but I’m a bit of
a wuss so we worked with experienced ice
diver we actually had to cut a hole in
the ice for him to go underwater with
the idea to go find the algae so that we
can bring it back to the lab to study
the skeleton of the algae when he went
down because sunlight can penetrate
through sea ice this was the visibility
he had you can see the rocky seafloor
and some of the fleshy green algae and
there for the first time at this site on
the large rocks we found my algae now
this was early July and there was still
sea ice so this plant that can grow for
650 years can do so under sea ice ten
months of the year so from this
collection we brought it back to the lab
and now we’re analyzing the skeleton to
see how has temperature changed in the
past at this
location in the Arctic how has seawater
pH changed and how is the properties of
the skeleton how is this algae doing is
the skeleton more fragile is it more
robust how is it doing how is the health
of this environment for these organisms
that live there I don’t have the answers
yet this is still a project that we’re
working on but I do know what’s
happening is that we’re changing our
environment because of our carbon
dioxide emissions we are causing a
warming and we are causing sea water pH
to decline now the good news to the
story if there is good news is that we
know what the problem is its carbon but
that also means we can do something
about it we can decide to shape the
future of our oceans and other planet to
make sure that they’re a healthy home
for everything that lives in it like my
coral and algae and all the things that
depend on it like us so even though it’s
a vast problem much faster than the
ocean is itself I know that by reducing
my own carbon dioxide emissions I can
make a difference so every time I ride
my bike instead of taking my car or
instead of flying far away but stay
close to home for a staycation or even
instead of just following meatless
Monday but also having more beans and
lentils on Tuesday Wednesday Thursday
Friday as well I reduce my carbon
dioxide emissions the other thing I can
do is that when I exercise my right to
vote I take into account the health of
our oceans and our planet when I make
that decision because if we all do this
the small things and the big things we
can change what our future planet is
going to look like we can reduce our
carbon dioxide emissions and by the end
of this century instead of warming three
four five degrees Celsius we will only
warm one degree and instead of
decreasing the sea water pH by about
half a pH unit we can only decrease it a
little bit more than it already has gone
down and this means that our ocean that
supports all these things both that live
in it and that depend on it things like
my algae that have been around for 650
years well maybe it’ll be around for 650 more thank you