TEDSummit 2019
Tim Flannery: Can seaweed help curb global warming?
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It's time for planetary-scale interventions to combat climate change -- and environmentalist Tim Flannery thinks seaweed can help. In a bold talk, he shares the epic carbon-capturing potential of seaweed, explaining how oceangoing seaweed farms created on a massive scale could trap all the carbon we emit into the atmosphere. Learn more about this potentially planet-saving solution -- and the work that's still needed to get there.
Tim Flannery - Environmentalist
Explorer and professor Tim Flannery seeks to grasp the big picture of planetary evolution and how humans can affect it -- for better or for worse. Full bio
Explorer and professor Tim Flannery seeks to grasp the big picture of planetary evolution and how humans can affect it -- for better or for worse. Full bio
Double-click the English transcript below to play the video.
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Oh, there's a lot of it.
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This is seaweed.
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It's pretty humble stuff.
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But it does have
some remarkable qualities.
some remarkable qualities.
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For one, it grows really fast.
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So the carbon that is part
of that seaweed,
of that seaweed,
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just a few weeks ago,
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was floating in the atmosphere
as atmospheric CO2,
as atmospheric CO2,
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driving all the adverse consequences
of climate change.
of climate change.
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For the moment, it's locked
safely away in the seaweed,
safely away in the seaweed,
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but when that seaweed rots --
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and by the smell of it,
it's not far away --
it's not far away --
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when it rots, that CO2 will be released
back to the atmosphere.
back to the atmosphere.
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Wouldn't it be fantastic
if we could find a way
if we could find a way
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of keeping that CO2 locked up long-term,
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and thereby significantly contributing
to solving the climate problem?
to solving the climate problem?
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What I'm talking about here is drawdown.
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It's now become the other half
of the climate challenge.
of the climate challenge.
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And that's because
we have delayed so long,
we have delayed so long,
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in terms of addressing climate change,
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that we now have to do two very big
and very difficult things at once.
and very difficult things at once.
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We have to cut our emissions
and clean our energy supply
and clean our energy supply
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at the same time that we draw
significant volumes
significant volumes
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of carbon dioxide out of the atmosphere.
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If we don't do that, about 25 percent
of the CO2 we put in the air
of the CO2 we put in the air
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will remain there,
by human standards, forever.
by human standards, forever.
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So we have to act.
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This is really a new phase
in addressing the climate crisis
in addressing the climate crisis
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and it demands new thinking.
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So, ideas like carbon offsets
really don't make sense
really don't make sense
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in the modern era.
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You know, when you offset something,
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you say, "I'll permit myself to put
some greenhouse gas into the atmosphere,
some greenhouse gas into the atmosphere,
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but then I'll offset it
by drawing it down."
by drawing it down."
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When you've got to both cut your emissions
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and draw down CO2,
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that thinking doesn't make sense anymore.
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And when we're talking about drawdown,
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we're talking about putting large volumes
of greenhouses gases, particularly CO2,
of greenhouses gases, particularly CO2,
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out of circulation.
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And to do that, we need a carbon price.
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We need a significant price
that we'll pay for that service
that we'll pay for that service
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that we'll all benefit from.
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We've made almost no progress so far
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with the second half
of the climate challenge.
of the climate challenge.
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It's not on most people's radar.
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And, you know, I must say,
at times, I hear people saying,
at times, I hear people saying,
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"I've lost hope that we can do anything
about the climate crisis."
about the climate crisis."
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And look, I've had my sleepless
nights too, I can tell you.
nights too, I can tell you.
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But I'm here today as an ambassador
for this humble weed, seaweed.
for this humble weed, seaweed.
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I think it has the potential
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to be a big part of addressing
the challenge of climate change
the challenge of climate change
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and a big part of our future.
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Now, what the scientists are telling us
we need to do over the next 80-odd years
we need to do over the next 80-odd years
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to the end of this century,
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is to cut our greenhouse gas emissions
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by three percent every year,
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and draw three gigatons of CO2
out of the atmosphere every year.
out of the atmosphere every year.
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Those numbers are so large
that they baffle us.
that they baffle us.
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But that's what the scientists
tell us we need to do.
tell us we need to do.
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I really hate showing this graph,
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but I'm sorry, I have to do it.
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It is very eloquent
in terms of telling the story
in terms of telling the story
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of my personal failure
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in terms of all the advocacy I've done
in climate change work
in climate change work
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and in fact, our collective failure
to address climate change.
to address climate change.
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You can see our trajectory there
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in terms of warming
and greenhouse gas concentrations.
and greenhouse gas concentrations.
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You can see all of the great
scientific announcements that we've made,
scientific announcements that we've made,
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saying how much danger
we face with climate change.
we face with climate change.
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You can see the political meetings.
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None of it has changed the trajectory.
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And this is why we need new thinking,
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we need a new approach.
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So how might we go about drawing down
greenhouse gases at a large scale?
greenhouse gases at a large scale?
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There's really only two ways of doing it,
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and I've done a very deep dive
into drawdown.
into drawdown.
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And I'll preempt my --
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And I would say this stuff comes up
smelling like roses at the end of the day.
smelling like roses at the end of the day.
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It does, it's one of the best options,
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but there are many, many possibilities.
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There are chemical pathways
and biological pathways.
and biological pathways.
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So two ways, really,
of getting the job done.
of getting the job done.
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The biological pathways are fantastic
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because the energy source
that's needed to drive them, the sun,
that's needed to drive them, the sun,
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is effectively free.
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We use the sun to drive
photosynthesis in plants,
photosynthesis in plants,
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break apart that CO2
and capture the carbon.
and capture the carbon.
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There are also chemical pathways.
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They sound ominous, but actually,
they're not bad at all.
they're not bad at all.
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The difficulty they face is
that we have to actually pay
that we have to actually pay
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for the energy
that's required to do the job
that's required to do the job
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or pay to facilitate that energy.
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Direct air capture is a great example
of a chemical pathway,
of a chemical pathway,
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and people are using that right now
to take CO2 out of the atmosphere
to take CO2 out of the atmosphere
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and manufacture biofuels
or manufacture plastics.
or manufacture plastics.
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Great progress is being made,
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but it will be many decades
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before those chemical pathways
are drawing down a gigaton of CO2 a year.
are drawing down a gigaton of CO2 a year.
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The biological pathways offer us
a lot more hope, I think,
a lot more hope, I think,
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in the short term.
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You've probably heard
about reforestation, planting trees,
about reforestation, planting trees,
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as a solution to the climate problem.
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You know, it's a fair question:
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Can we plant our way out
of this problem by using trees?
of this problem by using trees?
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I'm skeptical about that
for a number of reasons.
for a number of reasons.
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One is just the scale of the problem.
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All trees start as seeds,
little tiny things,
little tiny things,
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and it's many decades
before they've reached
before they've reached
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their full carbon-capture potential.
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And secondly,
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if you look at the land surface,
you see that it's so heavily utilized.
you see that it's so heavily utilized.
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We get our food from it,
we get our forestry products from it,
we get our forestry products from it,
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biodiversity protection
and water and everything else.
and water and everything else.
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To expect that we'll find enough space
to deal with this problem,
to deal with this problem,
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I think is going to be quite problematic.
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But if we look offshore,
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wee see a solution where there's already
an existing industry,
an existing industry,
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and where there's a clearer way forward.
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The oceans cover
about 70 percent of our planet.
about 70 percent of our planet.
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They play a really big role
in regulating our climate,
in regulating our climate,
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and if we can enhance
the growth of seaweed in them,
the growth of seaweed in them,
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we can use them, I think,
to develop a climate-altering crop.
to develop a climate-altering crop.
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There are so many
different kinds of seaweed,
different kinds of seaweed,
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there's unbelievable
genetic diversity in seaweed,
genetic diversity in seaweed,
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and they're very ancient;
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they were some of the first
multicellular organisms ever to evolve.
multicellular organisms ever to evolve.
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People are using special
kinds of seaweed now
kinds of seaweed now
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for particular purposes,
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like developing very high-quality
pharmaceutical products.
pharmaceutical products.
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But you can also use seaweed
to take a seaweed bath,
to take a seaweed bath,
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it's supposed to be good for your skin;
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I can't testify to that,
but you can do it.
but you can do it.
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The scalability is the big thing
about seaweed farming.
about seaweed farming.
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You know, if we could cover
nine percent of the world's ocean
nine percent of the world's ocean
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in seaweed farms,
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we could draw down the equivalent
of all of the greenhouse gases
of all of the greenhouse gases
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we put up in any one year,
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more than 50 gigatons.
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Now, I thought that was fantastic
when I first read it,
when I first read it,
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but I thought I'd better calculate how big
nine percent of the world's oceans is.
nine percent of the world's oceans is.
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It turns out, it's about
four and a half Australias,
four and a half Australias,
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the place I live in.
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And how close are we
to that at the moment?
to that at the moment?
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How many ocean-going seaweed farms
do we actually have out there?
do we actually have out there?
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Zero.
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But we do have some prototypes,
and therein lies some hope.
and therein lies some hope.
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This little drawing here of a seaweed farm
that's currently under construction
that's currently under construction
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tells you some very interesting
things about seaweed.
things about seaweed.
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You can see the seaweed
growing on that rack,
growing on that rack,
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25 meters down in the ocean there.
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It's really different
from anything you see on land.
from anything you see on land.
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And the reason being that, you know,
seaweed is not like trees,
seaweed is not like trees,
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it doesn't have nonproductive parts
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like roots and trunks
and branches and bark.
and branches and bark.
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The whole of the plant
is pretty much photosynthetic,
is pretty much photosynthetic,
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so it grows fast.
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Seaweed can grow a meter a day.
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And how do we sequester the carbon?
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Again, it's very different from on land.
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All you need to do
is cut that seaweed off --
is cut that seaweed off --
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drifts into the ocean abyss,
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Once it's down a kilometer,
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the carbon in that seaweed is effectively
out of the atmospheric system
out of the atmospheric system
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for centuries or millennia.
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Whereas if you plant a forest,
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you've got to worry
about forest fires, bugs, etc.,
about forest fires, bugs, etc.,
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releasing that carbon.
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The key to this farm, though,
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is that little pipe
going down into the depths.
going down into the depths.
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You know, the mid-ocean is basically
a vast biological desert.
a vast biological desert.
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There's no nutrients there
that were used up long ago.
that were used up long ago.
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But just 500 meters down,
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there is cool, very nutrient-rich water.
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And with just a little bit
of clean, renewable energy,
of clean, renewable energy,
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you can pump that water up
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and use the nutrients in it
to irrigate your seaweed crop.
to irrigate your seaweed crop.
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So I think this really has
so many benefits.
so many benefits.
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It's changing a biological desert,
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the mid-ocean,
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into a productive, maybe even
planet-saving solution.
planet-saving solution.
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So what could go wrong?
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Well, anything we're talking
about at this scale
about at this scale
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involves a planetary-scale intervention.
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And we have to be very careful.
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I think that piles of stinking seaweed
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are probably going to be
the least of our problems.
the least of our problems.
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There's other unforeseen things
that will happen.
that will happen.
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One of the things that really worries me,
when I talk about this,
when I talk about this,
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is the fate of biodiversity
in the deep ocean.
in the deep ocean.
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If we are putting gigatons of seaweed
into the deep ocean,
into the deep ocean,
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we're affecting life down there.
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The good news is that we know
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that a lot of seaweed
already reaches the deep ocean,
already reaches the deep ocean,
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after storms or through submarine canyons.
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So we're not talking
about a novel process here;
about a novel process here;
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we are talking about
enhancing a natural process.
enhancing a natural process.
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And we'll learn as we go.
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I mean, it may be that these ocean-going
seaweed farms will need to be mobile,
seaweed farms will need to be mobile,
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to distribute the seaweed
across vast areas of the ocean,
across vast areas of the ocean,
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rather than creating
a big stinking pile in one place.
a big stinking pile in one place.
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It may be that we'll need
to char the seaweed --
to char the seaweed --
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so create a sort of an inert,
mineral biochar
mineral biochar
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before we dispatch it into the deep.
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We won't know until we start the process,
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and we will learn effectively by doing.
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I just want to take you
to contemporary seaweed farming.
to contemporary seaweed farming.
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It's a big business --
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it's a six-billion-dollar-a-year business.
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These seaweed farms off South Korea --
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you can see them from space,
they are huge.
they are huge.
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And they're increasingly
not just seaweed farms.
not just seaweed farms.
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What people are doing in places like this
is something called ocean permaculture.
is something called ocean permaculture.
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And in ocean permaculture,
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you grow fish, shellfish
and seaweed all together.
and seaweed all together.
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And the reason it works so well
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is that the seaweed
makes the seawater less acid.
makes the seawater less acid.
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It provides an ideal environment
for growing marine protein.
for growing marine protein.
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If we covered nine percent
of the world's oceans
of the world's oceans
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in ocean permaculture,
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we would be producing enough protein
in the form of fish and shellfish
in the form of fish and shellfish
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to give every person
in a population of 10 billion
in a population of 10 billion
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200 kilograms of high-quality
protein per year.
protein per year.
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So, we've got a multipotent solution here.
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We can address climate change,
we can feed the world,
we can feed the world,
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we can deacidify the oceans.
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The economics of all of this
is going to be challenging.
is going to be challenging.
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We'll be investing many,
many billions of dollars
many billions of dollars
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into these solutions,
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and they will take decades
to get to the gigaton scale.
to get to the gigaton scale.
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The reason that I'm convinced
that this is going to happen
that this is going to happen
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is that unless we get the gas
out of the air,
out of the air,
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it is going to keep driving
adverse consequences.
adverse consequences.
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It will flood our cities,
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it will deprive us of food,
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it will cause all sorts of civil unrest.
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So anyone who's got a solution
to dealing with this problem
to dealing with this problem
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has a valuable asset.
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And already, as I've explained,
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ocean permaculture is well on the road
to being economically sustainable.
to being economically sustainable.
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You know, in the next 30 years,
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we have to go from being
a carbon-emitting economy
a carbon-emitting economy
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to a carbon-absorbing economy.
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And that doesn't seem like very long.
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But half of the greenhouse gases
that we've put into the atmosphere,
that we've put into the atmosphere,
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we've put there in the last 30 years.
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My argument is,
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if we can put the gas in in 30 years,
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we can pull it out in 30 years.
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And if you doubt how much
can be done over 30 years,
can be done over 30 years,
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just cast your mind back
a century, to 1919,
a century, to 1919,
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compare it with 1950.
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Now, in 1919, here in Edinburgh,
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you might have seen
a canvas and wood biplane.
a canvas and wood biplane.
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Thirty years later,
you'd be seeing jet aircraft.
you'd be seeing jet aircraft.
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Transport in the street
were horses in 1919.
were horses in 1919.
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By 1950, they're motor vehicles.
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1919, we had gun powder;
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1950, we had nuclear power.
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We can do a lot in a short period of time.
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But it all depends upon us believing
that we can find a solution.
that we can find a solution.
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Now what I would love to do
is bring together all of the people
is bring together all of the people
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with knowledge in this space.
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The engineers who know
how to build structures offshore,
how to build structures offshore,
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the seaweed farmers, the financiers,
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the government regulators,
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the people who understand
how things are done.
how things are done.
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And chart a way forward,
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say: How do we go from the existing
six-billion-dollar-a-year,
six-billion-dollar-a-year,
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inshore seaweed industry,
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to this new form of industry,
which has got so much potential,
which has got so much potential,
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but will require large
amounts of investment?
amounts of investment?
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I'm not a betting man, you know.
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But if I were,
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I'll tell you, my money
would be on that stuff,
would be on that stuff,
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it would be on seaweed.
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It's my hero.
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Thank you.
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(Applause)
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ABOUT THE SPEAKER
Tim Flannery - EnvironmentalistExplorer and professor Tim Flannery seeks to grasp the big picture of planetary evolution and how humans can affect it -- for better or for worse.
Why you should listen
A noted explorer who has published more than 140 peer-reviewed papers and named 25 living and 50 fossil mammal species, Tim Flannery has conducted research for more than 20 years in New Guinea and surrounding countries. He has served on the board of WWF International, the Australian Wildlife Conservancy, and as an advisor to the National Geographic Society. His books include The Future Eaters: An Ecological History of the Australasian Lands and People (which has been made into a three-part documentary series) and The Weather Makers: How Man Is Changing the Climate and What It Means for Life on Earth, which has been translated into more than 20 languages.
Flannery is the cofounder of the Australian Climate Council, which provides authoritative information, advice and solutions about climate change for ordinary citizens, and chair of the Ocean Forests Foundation. In 2007 he established and chaired the Copenhagen Climate Council, and in 2011 he was appointed Australia's first Climate Commissioner.
Tim Flannery | Speaker | TED.com