ABOUT THE SPEAKER
Charles C. Mann - Science journalist
Charles 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 Columbus1493: 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.

More profile about the speaker
Charles C. Mann | Speaker | TED.com
TED2018

Charles C. Mann: How will we survive when the population hits 10 billion?

Filmed:
2,753,413 views

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.
- Science journalist
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?
0
698
1150
00:14
No, no, no, by that, I meant,
1
2650
1565
00:16
how are we, homo sapiens "we" ...
2
4239
1681
00:17
(Laughter)
3
5944
1008
00:18
doing as a species?
4
6976
1151
00:20
(Laughter)
5
8151
1010
00:21
Now the typical way
to answer that question is this.
6
9185
2451
00:23
You choose some measure
of human physical well-being:
7
11660
3125
00:26
average longevity,
average calories per day,
8
14809
2698
00:29
average income, overall population,
that sort of thing,
9
17531
2642
00:32
and draw a graph of its value over time.
10
20197
2910
00:35
In almost every case,
you get the same result.
11
23131
2466
00:37
The line skitters along
at a low level for millennia,
12
25621
2691
00:40
then rockets up exponentially
in the 19th and 20th century.
13
28336
3436
00:44
Or choose a measure of consumption:
14
32535
2621
00:47
consumption of energy,
consumption of fresh water,
15
35180
2349
00:49
consumption of the world's photosynthesis,
16
37553
2071
00:51
and draw a graph of its value over time.
17
39648
2222
00:53
In the same way, the line skitters along
at a low level for millennia,
18
41894
4072
00:57
then rockets up exponentially
in the 19th and 20th century.
19
45990
4008
01:02
Biologists have a word for this: outbreak.
20
50731
2346
01:05
An outbreak is when
a population or species
21
53894
2613
01:08
exceeds the bounds of natural selection.
22
56531
2055
01:10
Natural selection ordinarily
keeps populations and species
23
58610
3016
01:13
within roughly defined limits.
24
61650
1682
01:16
Pests, parasites, lack of resources
prevent them from expanding too much.
25
64130
4211
01:20
But every now and then,
a species escapes its bounds.
26
68365
3439
01:24
Crown-of-thorns starfish
in the Indian Ocean,
27
72116
2392
01:26
zebra mussels in the Great Lakes,
spruce budworm here in Canada.
28
74532
3580
01:30
Populations explode,
a hundredfold, a thousandfold,
29
78136
3143
01:33
a millionfold.
30
81303
1206
01:35
So here's a fundamental
lesson from biology:
31
83023
2542
01:37
outbreaks in nature don't end well.
32
85589
2188
01:40
(Laughter)
33
88126
1150
01:41
Put a couple of protozoa
into a petri dish full of nutrient goo.
34
89660
3920
01:46
In their natural habitat, soil or water,
their environment constrains them.
35
94276
3872
01:50
In the petri dish, they have
an ocean of breakfast
36
98896
2375
01:53
and no natural enemies.
37
101295
1366
01:54
They eat and reproduce, eat and reproduce,
38
102685
2508
01:57
until bang, they hit
the edge of the petri dish,
39
105217
2259
01:59
at which point they either
drown in their own waste,
40
107500
2435
02:01
starve from lack of resources, or both.
41
109959
1905
02:03
The outbreak ends, always, badly.
42
111888
2708
02:06
Now, from the viewpoint of biology,
43
114953
2433
02:09
you and I are not fundamentally different
than the protozoa in the petri dish.
44
117410
3942
02:13
We're not special.
45
121884
1587
02:17
All the things that we, in our vanity,
think make us different --
46
125598
3136
02:20
art, science, technology, and so forth,
they don't matter.
47
128758
2766
02:23
We're an outbreak species,
48
131548
1269
02:24
we're going to hit the edge
of the petri dish, simple as that.
49
132841
3455
02:28
Well, the obvious question:
Is this actually true?
50
136320
2857
02:31
Are we in fact doomed
to hit the edge of the petri dish?
51
139766
2667
02:34
I'd like to set aside
this question for a moment
52
142457
2269
02:36
and ask you guys another one.
53
144750
1524
02:38
If we are going to escape biology,
how are we going to do it?
54
146298
3071
02:42
In the year 2050,
55
150242
1588
02:43
there will be almost
10 billion people in the world,
56
151854
2495
02:46
and all of those people will want
the things that you and I want:
57
154373
3139
02:49
nice cars, nice clothes, nice homes,
58
157536
3277
02:52
the odd chunk of Toblerone.
59
160837
1523
02:55
I mean, think of it:
Toblerone for 10 billion people.
60
163064
2491
02:57
How are we going to do this?
61
165579
1573
02:59
How are we going to feed everybody,
get water to everybody,
62
167176
2840
03:02
provide power to everybody,
avoid the worst impacts of climate change?
63
170040
3389
03:05
I'm a science journalist,
64
173453
1777
03:07
and I've been asking these questions
to researchers for years,
65
175254
3339
03:10
and in my experience, their answers
fall into two broad categories,
66
178617
3977
03:14
which I call "wizards" and "prophets."
67
182618
1959
03:16
Wizards, techno-whizzes,
68
184994
1814
03:18
believe that science and technology,
properly applied,
69
186832
2808
03:21
will let us produce
our way out of our dilemmas.
70
189664
2624
03:24
"Be smart, make more," they say.
71
192312
1677
03:26
"That way, everyone can win."
72
194013
1651
03:28
Prophets believe close to the opposite.
73
196537
2182
03:31
They see the world as governed
by fundamental ecological processes
74
199790
4091
03:35
with limits that we
transgress to our peril.
75
203905
2758
03:39
"Use less, conserve," they say.
76
207206
2016
03:41
"Otherwise, everybody's going to lose."
77
209246
2071
03:44
Wizards and prophets have been
butting their heads together for decades,
78
212261
3428
03:47
but they both believe that technology
is key to a successful future.
79
215713
3683
03:51
The trouble is, they envision
different types of technology
80
219420
3047
03:54
and different types of futures.
81
222491
1778
03:56
Wizards envision a world of glittering,
hyperefficient megacities
82
224995
5133
04:02
surrounded by vast tracts
of untouched nature,
83
230152
2962
04:05
economies that have
transitioned from atoms to bits,
84
233138
2620
04:07
dematerialized capitalist societies
85
235782
2041
04:09
that no longer depend
on exploiting nature.
86
237847
2229
04:12
Energy, to wizards,
comes from compact nuclear plants;
87
240755
2642
04:15
food from low-footprint farms
with ultraproductive,
88
243421
2842
04:18
genetically modified crops
tended by robots;
89
246287
2808
04:21
water from high-throughput
desalination plants,
90
249119
2516
04:23
which means we no longer
exploit rivers and aquifers.
91
251659
3126
04:27
Wizards envision all 10 billion of us
92
255208
1834
04:29
packed into ultradense
but walkable megacities,
93
257066
2643
04:31
an urbanized world
of maximum human aspiration
94
259733
2674
04:34
and maximum human liberty.
95
262431
1428
04:36
Now, prophets object to every bit of this.
96
264557
3508
04:40
You can't dematerialize
food and water, they point out.
97
268089
3155
04:43
They say, you can't eat bits,
98
271557
2136
04:45
and industrial agriculture has already
given us massive soil erosion,
99
273717
3524
04:49
huge coastal dead zones
and ruined soil microbiomes.
100
277265
2921
04:52
And you wizards, you want more of this?
101
280210
1947
04:54
And those giant desalination plants?
102
282181
2418
04:56
You know they generate
equally giant piles of toxic salt
103
284623
2969
04:59
that are basically
impossible to dispose of.
104
287616
2268
05:02
And those megacities you like?
105
290424
2184
05:04
Can you name me
an actually existing megacity
106
292632
3065
05:07
that really exists in the world today,
except for possibly Tokyo,
107
295721
3224
05:10
that isn't a cesspool
of corruption and inequality?
108
298969
3079
05:15
Instead, prophets pray for a world
of smaller, interconnected communities,
109
303055
6636
05:21
closer to the earth,
110
309715
2166
05:23
a more agrarian world
of maximum human connection
111
311905
3017
05:26
and reduced corporate control.
112
314946
1903
05:30
More people live
in the countryside in this vision,
113
318142
2731
05:32
with power provided by neighborhood-scale
solar and wind installations
114
320897
3341
05:36
that disappear into the background.
115
324262
1809
05:38
Prophets don't generate water
from giant desalination plants.
116
326698
3706
05:44
They capture it from rainfall,
117
332044
2508
05:46
and they reuse and recycle it endlessly.
118
334576
2469
05:49
And the food comes
from small-scale networks of farms
119
337069
4420
05:53
that focus on trees and tubers
120
341513
1906
05:55
rather than less productive cereals
like wheat and rice.
121
343443
3738
06:01
Above all, though, prophets envision
people changing their habits.
122
349286
3699
06:05
They don't drive to work,
they take their renewable-powered train.
123
353009
3110
06:08
They don't take 30-minute
hot showers every morning.
124
356143
2507
06:10
They eat, you know,
like Michael Pollan says,
125
358674
2461
06:13
real food, mostly plants, not too much.
126
361159
3895
06:17
Above all, prophets say
submitting to nature's restraints
127
365825
3508
06:21
leads to a freer, more democratic,
healthier way of life.
128
369357
4848
06:26
Now, wizards regard all this as hooey.
129
374967
2490
06:29
They see it as a recipe for narrowness,
regression, and global poverty.
130
377481
3468
06:34
Prophet-style agriculture, they say,
only extends the human footprint
131
382314
3318
06:37
and shunts more people
into low-wage agricultural labor.
132
385656
3048
06:40
Those neighborhood-run solar facilities,
133
388728
1931
06:42
they sound great,
134
390683
1764
06:44
but they depend on a technology
that doesn't exist yet.
135
392471
2705
06:47
They're a fantasy.
136
395200
1354
06:49
And recycling water? It's a brake
on growth and development.
137
397012
2826
06:51
Above all, though, wizards object
to the prophets' emphasis
138
399862
3483
06:55
on wide-scale social engineering,
139
403369
2038
06:57
which they see as deeply anti-democratic.
140
405431
2438
07:01
If the history of the last two centuries
was one of unbridled growth,
141
409105
3904
07:05
the history of the coming century
may well be the choice we make
142
413033
3185
07:08
as a species between these two paths.
143
416242
2215
07:11
These are the arguments that will be
resolved, in one way or another,
144
419021
3897
07:14
by our children's generation,
145
422942
1464
07:16
the generation that will come
into the world of 10 billion.
146
424430
2816
07:19
Now, but wait, by this point,
biologists should be rolling their eyes
147
427270
3262
07:22
so loud you can barely hear me speak.
148
430556
1886
07:24
They should be saying,
all of this, wizards, prophets,
149
432466
3697
07:28
it's a pipe dream.
150
436187
1352
07:29
It doesn't matter which illusory path
you think you're taking.
151
437563
4168
07:34
Outbreaks in nature don't end well.
152
442736
2436
07:37
I mean, you think the protozoa
see the edge of the petri dish approaching
153
445196
3476
07:40
and say, "Hey guys,
time to change society"?
154
448696
2095
07:42
No. They just let her rip.
155
450815
2158
07:44
That's what life does,
and we're part of life.
156
452997
2531
07:47
We'll do the same thing. Deal with it.
157
455552
2119
07:50
Well, if you're a follower of Darwin,
you have to take this into consideration.
158
458242
5647
07:56
I mean, the basic counterargument
boils down to: "We're special."
159
464500
3723
08:00
How lame is that?
160
468762
1259
08:02
(Laughter)
161
470045
1491
08:03
I mean, we can accumulate
and share knowledge
162
471560
2120
08:05
and use it to guide our future.
163
473704
1824
08:07
Well, are we actually doing this?
164
475552
1724
08:09
Is there any evidence that we're actually
using our accumulated, shared knowledge
165
477300
4777
08:15
to guarantee our long-term prosperity?
166
483514
2008
08:18
It's pretty easy to say no.
167
486093
1667
08:20
If you're a wizard,
168
488398
907
08:21
and you believe that hyperproductive,
genetically engineered crops
169
489321
3438
08:24
are key to feeding everyone
in tomorrow's world,
170
492783
2363
08:27
you have to worry that 20 years
171
495170
2785
08:29
of scientists demonstrating
that they are safe to consume
172
497979
2722
08:32
has failed to convince the public
to embrace this technology.
173
500725
2906
08:35
If you're a prophet
174
503655
1314
08:36
and you believe that key to solving
today's growing shortage of fresh water
175
504993
4477
08:41
is to stop wasting it,
176
509494
1951
08:43
you have to worry
that cities around the world,
177
511469
2897
08:46
in rich places as well as poor,
178
514390
1800
08:48
routinely lose a quarter
or more of their water
179
516214
2587
08:50
to leaky and contaminated pipes.
180
518825
2135
08:53
I mean, Cape Town, just a little
while ago, almost ran out of water.
181
521515
3529
08:57
Cape Town loses a third
of its water to leaky pipes.
182
525068
2567
08:59
This problem has been
getting worse for decades,
183
527659
2317
09:02
and remarkably little
has been done about it.
184
530000
2595
09:04
If you're a wizard, and you think
that clean, abundant,
185
532619
3249
09:07
carbon-free nuclear power
is key to fighting climate change,
186
535892
2869
09:10
then you have to worry
187
538785
1241
09:12
that the public willingness
to build nukes is going down.
188
540050
2770
09:15
If you're a prophet, and you think
that the solution to the same problem
189
543455
3436
09:18
is these neighborhood-run solar facilities
shuttling power back and forth,
190
546915
3578
09:22
you have to worry that no nation
anywhere in the world
191
550517
2754
09:25
has devoted anything like the resources
necessary to develop this technology
192
553295
3969
09:29
and deploy it in the time that we need it.
193
557288
2503
09:31
And if you're on either side,
wizard or prophet,
194
559815
2338
09:34
you have to worry that, despite
the massive alarm about climate change,
195
562177
4548
09:38
the amount of energy generated every year
from fossil fuels has gone up
196
566749
3953
09:42
by about 30 percent
since the beginning of this century.
197
570726
3331
09:46
So, still think we're different
than the protozoa?
198
574443
3317
09:50
Still think we're special?
199
578498
2270
09:54
Actually, it's even worse than that.
200
582392
2563
09:56
(Laughter)
201
584979
2588
09:59
We're not in the streets.
202
587591
1251
10:00
No seriously, if there's a difference
between us and the protozoa,
203
588866
3175
10:04
a difference that matters,
204
592065
1542
10:05
it's not just our art and science
and technology and so forth --
205
593631
3077
10:08
it's that we can yell and scream,
we can go out into the streets,
206
596732
3231
10:11
and, over time,
change the way society works,
207
599987
2118
10:14
but we're not doing it.
208
602129
1254
10:15
Wizards have been arguing
literally for decades
209
603407
2424
10:17
that nuclear power is key
to resolving climate change.
210
605855
4976
10:24
But the first pro-nuke march in history
occurred less than two years ago,
211
612174
4229
10:28
and it was dwarfed by the anti-nuke
marches of the past.
212
616427
3262
10:31
Prophets have been arguing,
again literally for decades,
213
619713
3126
10:34
that conservation is key
to keeping freshwater supplies
214
622863
3763
10:38
without destroying the ecosystems
that generate those freshwater supplies.
215
626650
3835
10:42
But in the history of humankind,
there has never been a street
216
630509
2911
10:45
full of angry protesters
waving signs about leaky pipes.
217
633444
2917
10:48
In fact, most of the political
activity in this sphere
218
636985
3598
10:52
has been wizards and prophets
fighting each other, protesting each other
219
640607
3491
10:56
rather than recognizing that they are,
fundamentally, on the same side.
220
644122
3738
10:59
After all, these people are concerned
about the same thing:
221
647884
3407
11:03
How are we going to make our way
in the world of 10 billion?
222
651315
3597
11:06
The first step towards generating
that necessary social movement,
223
654936
3134
11:10
creating that critical mass and getting
that yelling and screaming going
224
658094
3444
11:13
seems obvious:
wizards and prophets join together.
225
661562
2361
11:15
But how are you going to do this,
given the decades of hostility?
226
663947
3150
11:19
One way might be this:
227
667121
1174
11:20
Each side agrees to accept
the fundamental premises of the other.
228
668319
4349
11:25
Accept that nuclear power
is safe and carbon-free,
229
673837
3397
11:29
and that uranium mines
can be hideously dirty
230
677258
2547
11:31
and that putting large volumes
of toxic waste on rickety trains
231
679829
4325
11:36
and shuttling them around
the countryside is a terrible idea.
232
684178
3007
11:40
To me, this leads rather quickly
to a vision of small,
233
688122
3533
11:43
neighborhood scale, temporary nukes,
234
691679
2668
11:46
nuclear power as a bridge technology
while we develop and deploy renewables.
235
694371
3620
11:50
Or accept that genetically
modified crops are safe
236
698015
3701
11:53
and that industrial agriculture
has caused huge environmental problems.
237
701740
3691
11:57
To me, this leads rather quickly
to a vision of plant scientists
238
705455
4250
12:01
devoting much more of their attention
to tree and tuber crops,
239
709729
3147
12:04
which can be much more
productive than cereals,
240
712900
3008
12:07
use much less water than cereals,
and cause much less erosion than cereals.
241
715932
3761
12:11
These are just ideas
from a random journalist.
242
719717
2187
12:13
I'm sure there's a hundred better ones
right here in this room.
243
721928
3054
12:17
The main point is,
244
725006
1151
12:18
wizards and prophets working together
have many paths to success.
245
726181
3999
12:22
And success would mean
much more than mere survival,
246
730204
2672
12:24
important though that is.
247
732900
1251
12:26
I mean, if humankind somehow
survives its own outbreak,
248
734175
2985
12:29
if we get food to everybody,
get water to everybody,
249
737184
2442
12:31
get power to everybody,
250
739650
1157
12:32
if we avoid the worst effects
of climate change,
251
740831
4097
12:36
if we somehow safeguard the biome,
252
744952
2059
12:39
it would be amazing.
253
747035
1230
12:41
It would say, I think,
254
749405
1781
12:43
even to a hardened cynic like me,
255
751210
2159
12:45
maybe we really are special.
256
753393
1451
12:47
Thank you.
257
755615
1151
12:48
(Applause)
258
756790
7000

▲Back to top

ABOUT THE SPEAKER
Charles C. Mann - Science journalist
Charles 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 Columbus1493: 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.

More profile about the speaker
Charles C. Mann | Speaker | TED.com