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Lucy Buxton: Good morning Chifley and good morning Hambledon.
My name is Lucy and I'm a marine biologist and I study climate change.
So I'm really excited to be with you all here today and hopefully you guys will learn something a little bit more about climate change
and why the oceans are very, very important in stabilising climate and how we need to protect them.
Okay?
So let's get started. Alright. Okay, so what do marine biologists do?
Does anyone know what marine biologists do?
Yeah.
Student: They study sea creatures and all of those kind of stuff.
Lucy: Yeah that's right we study all the plants and animals and the water itself.
So everything to do with the oceans.
But the oceans aren't like land. They're not two dimensional, they're three dimensional.
So you can also go up and down and left and right and that means that the light changes a lot with depth.
And also temperature changes a lot with depth so there are all sorts of different organisms that are very well adapted for living in all of
these different environments and you may have seen this same thing happen on land.
So you got forests and deserts and mountains and marshlands and all of those sorts of things and the same is true for underneath the water.
So there are warm tropical systems like the Great Barrier Reef and there are cold systems like Antarctica where penguins and things like that may live or fur seals.
And unlike the land where you can just drive up and have a look at a tree and measure how tall it is and take samples of the leaves and things like that,
we can't breathe underneath water so it makes it very difficult for us to do our work and we need special types of equipment.
So some of the equipment you guys may have seen before when you go snorkelling. Do you use things like these?
Yeah, those certainly help and we are not very good swimmers in comparison to fish so we need to use things like these, fins, and if you
want to stay underneath the water for a long time you probably need to use scuba equipment, have you seen that before? Yeah?
However, if you're a scientist and you need to study right at the bottom of the ocean, you can't go down there because its really,
really difficult and cold and the pressure is huge so we use remote vehicles like robots and things like that, that can go all the way
down to the bottom of the ocean and take samples.
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Lucy Buxton: Okay, so what do I do? Well, I work at the University of Technology in Sydney and what we do there is we mainly study the
plants that live in the ocean and do you guys know about photosynthesis?
Yeah? Sort of?
Okay well photosynthesis the plants absorb carbon dioxide and they use light to turn that carbon dioxide into sugar which is their food
and then they breathe out oxygen which is what we breathe so it's the opposite of respiration.
So plants are really, really important both on land and in the ocean but what I look at is a very, very small plant, these tiny, tiny little
ones which are probably about the width of the human hair so you can't see them usually with your naked eye but they are everywhere in the ocean.
There are tonnes and tonnes of different types of species, this is just one this is a photograph of one taken under a microscope and if
you've been swimming and have swallowed a mouthful of sea water I can guarantee you that you would've swallowed a bunch of these guys.
But don't worry, they're not dangerous. They won't do anything to you but they are all swimming out through the ocean. But other people
in my laboratory study much bigger organisms like corals and coral reefs.
This was a picture taken up on the Great Barrier Reef and this is a magnification of what a coral polyp looks like.
So those are all the little animals that live inside the hard coral structures.
And more pictures of coral reefs. And then some people study fish as well. This is a manta ray, and that's me and we were swimming out
there and we were very lucky that they came swimming up beneath us.
And then other people go right down to the bottom of the world, down to Antarctica, to the ice. And they study all the plants that live
swimming around in these huge ocean currents in the cold, cold water.
So it's quite a varied job and when you get to the bottom of the ice you get to see lovely things like penguins.
And this is my colleague Ross and he was taking ice cores from these ice sheets to look at the plants that live inside the ice. And quite
often these penguins waddle around like the types you see in the movies perhaps.
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Lucy Buxton: Okay, so climate change.
Climate change is caused in part by carbon dioxide and we refer to that sometimes as CO2 and do you know where carbon dioxide comes from?
Yeah?
Student: After we breathe it out.
Lucy: Yeah, absolutely. That's one source.
Another major source of it is from burning fossil fuels.
You may have heard fossil fuels those are things like coal and oil and also wood.
So when you burn things like that which is needed to produce electricity, you release lots and lots of carbon dioxide and that is contributing to global warming.
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Lucy Buxton: Okay, so next we are going to learn how carbon dioxide creates climate change.
So as you already pointed out carbon dioxide we breathe it out when we respire.
So there is naturally occurring amounts of carbon dioxide in the atmosphere and that's really, really important because in small
amounts carbon dioxide helps to regulate the earth's climate.
And the way it does this is that sun comes in through our atmosphere and bounces off the earth and then some of it bounces straight
back out again into the universe or into space and that heat or that energy is then lost.
However, if there are carbon dioxide molecules in the atmosphere and if the sun's ray bounces off the ground, off the earth, and then hits a
carbon dioxide molecule it doesn't escape into space, it gets trapped inside the atmosphere and its heat gets trapped inside the
atmosphere too, and that's why the conditions that we enjoy today like most warm days about 23 to 25 degrees, that's how that happens.
However, if more and more carbon dioxide gets into the atmosphere then more and more of those sun's rays keep on getting trapped and
that's what's causing the earth to heat up.