TED2018
Charles C. Mann: How will we survive when the population hits 10 billion?
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By 2050, an estimated 10 billion people will live on earth. How are we going to provide everybody with basic needs while also avoiding the worst impacts of climate change? In a talk packed with wit and wisdom, science journalist Charles C. Mann breaks down the proposed solutions and finds that the answers fall into two camps -- wizards and prophets -- while offering his own take on the best path to survival.
Charles C. Mann - Science journalist
Charles C. Mann calls himself "a fella who tries to find out interesting things and tell others about them." Full bio
Charles C. Mann calls himself "a fella who tries to find out interesting things and tell others about them." Full bio
Double-click the English transcript below to play the video.
00:12
How are we doing?
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No, no, no, by that, I meant,
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how are we, homo sapiens "we" ...
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(Laughter)
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doing as a species?
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(Laughter)
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Now the typical way
to answer that question is this.
to answer that question is this.
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You choose some measure
of human physical well-being:
of human physical well-being:
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average longevity,
average calories per day,
average calories per day,
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average income, overall population,
that sort of thing,
that sort of thing,
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and draw a graph of its value over time.
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In almost every case,
you get the same result.
you get the same result.
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The line skitters along
at a low level for millennia,
at a low level for millennia,
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then rockets up exponentially
in the 19th and 20th century.
in the 19th and 20th century.
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Or choose a measure of consumption:
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consumption of energy,
consumption of fresh water,
consumption of fresh water,
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consumption of the world's photosynthesis,
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and draw a graph of its value over time.
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In the same way, the line skitters along
at a low level for millennia,
at a low level for millennia,
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then rockets up exponentially
in the 19th and 20th century.
in the 19th and 20th century.
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01:02
Biologists have a word for this: outbreak.
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An outbreak is when
a population or species
a population or species
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exceeds the bounds of natural selection.
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Natural selection ordinarily
keeps populations and species
keeps populations and species
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within roughly defined limits.
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Pests, parasites, lack of resources
prevent them from expanding too much.
prevent them from expanding too much.
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But every now and then,
a species escapes its bounds.
a species escapes its bounds.
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Crown-of-thorns starfish
in the Indian Ocean,
in the Indian Ocean,
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zebra mussels in the Great Lakes,
spruce budworm here in Canada.
spruce budworm here in Canada.
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Populations explode,
a hundredfold, a thousandfold,
a hundredfold, a thousandfold,
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a millionfold.
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So here's a fundamental
lesson from biology:
lesson from biology:
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outbreaks in nature don't end well.
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(Laughter)
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Put a couple of protozoa
into a petri dish full of nutrient goo.
into a petri dish full of nutrient goo.
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In their natural habitat, soil or water,
their environment constrains them.
their environment constrains them.
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In the petri dish, they have
an ocean of breakfast
an ocean of breakfast
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and no natural enemies.
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They eat and reproduce, eat and reproduce,
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until bang, they hit
the edge of the petri dish,
the edge of the petri dish,
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at which point they either
drown in their own waste,
drown in their own waste,
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starve from lack of resources, or both.
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The outbreak ends, always, badly.
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Now, from the viewpoint of biology,
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you and I are not fundamentally different
than the protozoa in the petri dish.
than the protozoa in the petri dish.
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We're not special.
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All the things that we, in our vanity,
think make us different --
think make us different --
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art, science, technology, and so forth,
they don't matter.
they don't matter.
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We're an outbreak species,
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we're going to hit the edge
of the petri dish, simple as that.
of the petri dish, simple as that.
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Well, the obvious question:
Is this actually true?
Is this actually true?
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Are we in fact doomed
to hit the edge of the petri dish?
to hit the edge of the petri dish?
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I'd like to set aside
this question for a moment
this question for a moment
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and ask you guys another one.
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If we are going to escape biology,
how are we going to do it?
how are we going to do it?
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In the year 2050,
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there will be almost
10 billion people in the world,
10 billion people in the world,
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and all of those people will want
the things that you and I want:
the things that you and I want:
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nice cars, nice clothes, nice homes,
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the odd chunk of Toblerone.
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I mean, think of it:
Toblerone for 10 billion people.
Toblerone for 10 billion people.
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How are we going to do this?
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How are we going to feed everybody,
get water to everybody,
get water to everybody,
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provide power to everybody,
avoid the worst impacts of climate change?
avoid the worst impacts of climate change?
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I'm a science journalist,
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and I've been asking these questions
to researchers for years,
to researchers for years,
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and in my experience, their answers
fall into two broad categories,
fall into two broad categories,
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which I call "wizards" and "prophets."
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Wizards, techno-whizzes,
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believe that science and technology,
properly applied,
properly applied,
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will let us produce
our way out of our dilemmas.
our way out of our dilemmas.
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"Be smart, make more," they say.
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"That way, everyone can win."
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Prophets believe close to the opposite.
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They see the world as governed
by fundamental ecological processes
by fundamental ecological processes
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with limits that we
transgress to our peril.
transgress to our peril.
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"Use less, conserve," they say.
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"Otherwise, everybody's going to lose."
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Wizards and prophets have been
butting their heads together for decades,
butting their heads together for decades,
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but they both believe that technology
is key to a successful future.
is key to a successful future.
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The trouble is, they envision
different types of technology
different types of technology
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and different types of futures.
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Wizards envision a world of glittering,
hyperefficient megacities
hyperefficient megacities
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surrounded by vast tracts
of untouched nature,
of untouched nature,
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economies that have
transitioned from atoms to bits,
transitioned from atoms to bits,
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dematerialized capitalist societies
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that no longer depend
on exploiting nature.
on exploiting nature.
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Energy, to wizards,
comes from compact nuclear plants;
comes from compact nuclear plants;
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food from low-footprint farms
with ultraproductive,
with ultraproductive,
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genetically modified crops
tended by robots;
tended by robots;
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water from high-throughput
desalination plants,
desalination plants,
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which means we no longer
exploit rivers and aquifers.
exploit rivers and aquifers.
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Wizards envision all 10 billion of us
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packed into ultradense
but walkable megacities,
but walkable megacities,
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an urbanized world
of maximum human aspiration
of maximum human aspiration
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and maximum human liberty.
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Now, prophets object to every bit of this.
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You can't dematerialize
food and water, they point out.
food and water, they point out.
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They say, you can't eat bits,
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and industrial agriculture has already
given us massive soil erosion,
given us massive soil erosion,
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huge coastal dead zones
and ruined soil microbiomes.
and ruined soil microbiomes.
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And you wizards, you want more of this?
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And those giant desalination plants?
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You know they generate
equally giant piles of toxic salt
equally giant piles of toxic salt
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that are basically
impossible to dispose of.
impossible to dispose of.
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And those megacities you like?
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Can you name me
an actually existing megacity
an actually existing megacity
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that really exists in the world today,
except for possibly Tokyo,
except for possibly Tokyo,
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that isn't a cesspool
of corruption and inequality?
of corruption and inequality?
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Instead, prophets pray for a world
of smaller, interconnected communities,
of smaller, interconnected communities,
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closer to the earth,
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a more agrarian world
of maximum human connection
of maximum human connection
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and reduced corporate control.
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More people live
in the countryside in this vision,
in the countryside in this vision,
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with power provided by neighborhood-scale
solar and wind installations
solar and wind installations
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that disappear into the background.
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Prophets don't generate water
from giant desalination plants.
from giant desalination plants.
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They capture it from rainfall,
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and they reuse and recycle it endlessly.
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And the food comes
from small-scale networks of farms
from small-scale networks of farms
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that focus on trees and tubers
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rather than less productive cereals
like wheat and rice.
like wheat and rice.
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Above all, though, prophets envision
people changing their habits.
people changing their habits.
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They don't drive to work,
they take their renewable-powered train.
they take their renewable-powered train.
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They don't take 30-minute
hot showers every morning.
hot showers every morning.
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They eat, you know,
like Michael Pollan says,
like Michael Pollan says,
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real food, mostly plants, not too much.
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Above all, prophets say
submitting to nature's restraints
submitting to nature's restraints
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leads to a freer, more democratic,
healthier way of life.
healthier way of life.
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Now, wizards regard all this as hooey.
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They see it as a recipe for narrowness,
regression, and global poverty.
regression, and global poverty.
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Prophet-style agriculture, they say,
only extends the human footprint
only extends the human footprint
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and shunts more people
into low-wage agricultural labor.
into low-wage agricultural labor.
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Those neighborhood-run solar facilities,
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they sound great,
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but they depend on a technology
that doesn't exist yet.
that doesn't exist yet.
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They're a fantasy.
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And recycling water? It's a brake
on growth and development.
on growth and development.
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Above all, though, wizards object
to the prophets' emphasis
to the prophets' emphasis
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on wide-scale social engineering,
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which they see as deeply anti-democratic.
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If the history of the last two centuries
was one of unbridled growth,
was one of unbridled growth,
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the history of the coming century
may well be the choice we make
may well be the choice we make
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as a species between these two paths.
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These are the arguments that will be
resolved, in one way or another,
resolved, in one way or another,
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by our children's generation,
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the generation that will come
into the world of 10 billion.
into the world of 10 billion.
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Now, but wait, by this point,
biologists should be rolling their eyes
biologists should be rolling their eyes
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so loud you can barely hear me speak.
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They should be saying,
all of this, wizards, prophets,
all of this, wizards, prophets,
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it's a pipe dream.
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It doesn't matter which illusory path
you think you're taking.
you think you're taking.
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Outbreaks in nature don't end well.
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I mean, you think the protozoa
see the edge of the petri dish approaching
see the edge of the petri dish approaching
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and say, "Hey guys,
time to change society"?
time to change society"?
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No. They just let her rip.
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That's what life does,
and we're part of life.
and we're part of life.
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We'll do the same thing. Deal with it.
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Well, if you're a follower of Darwin,
you have to take this into consideration.
you have to take this into consideration.
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I mean, the basic counterargument
boils down to: "We're special."
boils down to: "We're special."
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How lame is that?
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(Laughter)
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I mean, we can accumulate
and share knowledge
and share knowledge
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and use it to guide our future.
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Well, are we actually doing this?
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Is there any evidence that we're actually
using our accumulated, shared knowledge
using our accumulated, shared knowledge
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to guarantee our long-term prosperity?
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It's pretty easy to say no.
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If you're a wizard,
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and you believe that hyperproductive,
genetically engineered crops
genetically engineered crops
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are key to feeding everyone
in tomorrow's world,
in tomorrow's world,
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you have to worry that 20 years
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of scientists demonstrating
that they are safe to consume
that they are safe to consume
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has failed to convince the public
to embrace this technology.
to embrace this technology.
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If you're a prophet
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and you believe that key to solving
today's growing shortage of fresh water
today's growing shortage of fresh water
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is to stop wasting it,
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you have to worry
that cities around the world,
that cities around the world,
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in rich places as well as poor,
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routinely lose a quarter
or more of their water
or more of their water
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to leaky and contaminated pipes.
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I mean, Cape Town, just a little
while ago, almost ran out of water.
while ago, almost ran out of water.
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Cape Town loses a third
of its water to leaky pipes.
of its water to leaky pipes.
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This problem has been
getting worse for decades,
getting worse for decades,
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and remarkably little
has been done about it.
has been done about it.
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If you're a wizard, and you think
that clean, abundant,
that clean, abundant,
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carbon-free nuclear power
is key to fighting climate change,
is key to fighting climate change,
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then you have to worry
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that the public willingness
to build nukes is going down.
to build nukes is going down.
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If you're a prophet, and you think
that the solution to the same problem
that the solution to the same problem
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is these neighborhood-run solar facilities
shuttling power back and forth,
shuttling power back and forth,
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you have to worry that no nation
anywhere in the world
anywhere in the world
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has devoted anything like the resources
necessary to develop this technology
necessary to develop this technology
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and deploy it in the time that we need it.
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And if you're on either side,
wizard or prophet,
wizard or prophet,
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you have to worry that, despite
the massive alarm about climate change,
the massive alarm about climate change,
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the amount of energy generated every year
from fossil fuels has gone up
from fossil fuels has gone up
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by about 30 percent
since the beginning of this century.
since the beginning of this century.
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So, still think we're different
than the protozoa?
than the protozoa?
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Still think we're special?
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Actually, it's even worse than that.
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(Laughter)
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We're not in the streets.
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No seriously, if there's a difference
between us and the protozoa,
between us and the protozoa,
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a difference that matters,
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it's not just our art and science
and technology and so forth --
and technology and so forth --
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it's that we can yell and scream,
we can go out into the streets,
we can go out into the streets,
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and, over time,
change the way society works,
change the way society works,
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but we're not doing it.
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Wizards have been arguing
literally for decades
literally for decades
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that nuclear power is key
to resolving climate change.
to resolving climate change.
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But the first pro-nuke march in history
occurred less than two years ago,
occurred less than two years ago,
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and it was dwarfed by the anti-nuke
marches of the past.
marches of the past.
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Prophets have been arguing,
again literally for decades,
again literally for decades,
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that conservation is key
to keeping freshwater supplies
to keeping freshwater supplies
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without destroying the ecosystems
that generate those freshwater supplies.
that generate those freshwater supplies.
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But in the history of humankind,
there has never been a street
there has never been a street
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full of angry protesters
waving signs about leaky pipes.
waving signs about leaky pipes.
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In fact, most of the political
activity in this sphere
activity in this sphere
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has been wizards and prophets
fighting each other, protesting each other
fighting each other, protesting each other
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rather than recognizing that they are,
fundamentally, on the same side.
fundamentally, on the same side.
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After all, these people are concerned
about the same thing:
about the same thing:
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How are we going to make our way
in the world of 10 billion?
in the world of 10 billion?
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The first step towards generating
that necessary social movement,
that necessary social movement,
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creating that critical mass and getting
that yelling and screaming going
that yelling and screaming going
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seems obvious:
wizards and prophets join together.
wizards and prophets join together.
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But how are you going to do this,
given the decades of hostility?
given the decades of hostility?
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One way might be this:
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Each side agrees to accept
the fundamental premises of the other.
the fundamental premises of the other.
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Accept that nuclear power
is safe and carbon-free,
is safe and carbon-free,
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and that uranium mines
can be hideously dirty
can be hideously dirty
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and that putting large volumes
of toxic waste on rickety trains
of toxic waste on rickety trains
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and shuttling them around
the countryside is a terrible idea.
the countryside is a terrible idea.
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To me, this leads rather quickly
to a vision of small,
to a vision of small,
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neighborhood scale, temporary nukes,
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nuclear power as a bridge technology
while we develop and deploy renewables.
while we develop and deploy renewables.
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Or accept that genetically
modified crops are safe
modified crops are safe
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and that industrial agriculture
has caused huge environmental problems.
has caused huge environmental problems.
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To me, this leads rather quickly
to a vision of plant scientists
to a vision of plant scientists
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12:01
devoting much more of their attention
to tree and tuber crops,
to tree and tuber crops,
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which can be much more
productive than cereals,
productive than cereals,
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use much less water than cereals,
and cause much less erosion than cereals.
and cause much less erosion than cereals.
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These are just ideas
from a random journalist.
from a random journalist.
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I'm sure there's a hundred better ones
right here in this room.
right here in this room.
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The main point is,
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12:18
wizards and prophets working together
have many paths to success.
have many paths to success.
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And success would mean
much more than mere survival,
much more than mere survival,
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important though that is.
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I mean, if humankind somehow
survives its own outbreak,
survives its own outbreak,
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if we get food to everybody,
get water to everybody,
get water to everybody,
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get power to everybody,
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if we avoid the worst effects
of climate change,
of climate change,
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if we somehow safeguard the biome,
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it would be amazing.
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It would say, I think,
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even to a hardened cynic like me,
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maybe we really are special.
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Thank you.
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(Applause)
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ABOUT THE SPEAKER
Charles C. Mann - Science journalistCharles C. Mann calls himself "a fella who tries to find out interesting things and tell others about them."
Why you should listen
Twenty years ago, on the day his daughter was born, Charles C. Mann suddenly realized that by the time she reaches his age, there will be almost ten billion people in the world. How is that going to work? How are we going to feed everybody, get water to everybody, get power to everybody and avoid the worst impacts of climate change? Is there any hope we can do all of this?
As a science journalist, Mann has been asking these questions to researchers for years. His TED2018 talk is his best effort to explain the kind of answers he gets, and what they mean -- all in 12 minutes.
Mann is the author of 1491: New Revelations of the Americas Before Columbus, 1493: Uncovering the New World Columbus Created and his latest, The Wizard and the Prophet: Two Remarkable Scientists and Their Dueling Visions to Shape Tomorrow's World.
Charles C. Mann | Speaker | TED.com