What If the Human Population Kept Growing and Couldn't Stop? — Transcript

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1. 0:00What if the human population kept
2. 0:02growing and couldn't stop?
3. 0:08Right now, there are about 8 billion of
4. 0:11us.
5. 0:13Now, imagine a perfect world. Every
6. 0:16year, there are 1%more of us forever.
7. 0:20How far can that go? And where would we
8. 0:23all live?
9. 0:25At that rate, there are twice as many of
10. 0:27us every 70 years.
11. 0:32So, cities do what they've always done.
12. 0:35They grow up. Each new tower holds as
13. 0:38many people as a small town.
14. 0:44Around 2070, the first flying cars take
15. 0:47to the air.
16. 0:51With this many people working on new
17. 0:53ideas, inventions come faster than ever.
18. 0:58By the end of the century, 16 billion
19. 1:01people. And there's still room.
20. 1:11[music] By now, there are towns on the
21. 1:13moon and the first cities on Mars.
22. 1:17Rockets leave every few minutes. Each
23. 1:19one carrying about 100 people.
24. 1:25[music] But Earth adds more than 150
25. 1:27million people every year.
26. 1:30Even a launch every minute all year
27. 1:33would only move about 50 million.
28. 1:39So, space gets its cities, but almost
29. 1:42everyone stays on Earth.
30. 1:49By 2200, there isn't enough farmland
31. 1:52left to feed everyone.
32. 1:54So, all of our food is grown inside in
33. 1:56towers. And cities spread onto land
34. 1:59nobody wanted.
35. 2:01[music]
36. 2:08[music]
37. 2:08The Sahara is almost as big as the
38. 2:11United States. Within one lifetime, it's
39. 2:14a single city.
40. 2:19More people live here now than lived on
41. 2:21all of Earth in 2026.
42. 2:25Every desert on Earth goes the same way.
43. 2:31The last empty continent is Antarctica.
44. 2:34It's colder than a freezer, so its
45. 2:36cities go under glass.
46. 2:45Inside, it's a warm spring day all year
47. 2:48round.
48. 2:51By 2280, 100 billion people. That's 12
49. 2:55times everyone alive today.
50. 3:02When there's no more land to spread
51. 3:03onto, buildings stop being buildings.
52. 3:07Each of these towers is a city, more
53. 3:10than a mile tall.
54. 3:12You could live your whole life in one
55. 3:14and never go outside.
56. 3:23Soon, every bit of land on Earth is as
57. 3:26packed as the middle of a big city.
58. 3:31That thin line in the distance is an
59. 3:33elevator to space. Riding it up costs
60. 3:36far less than a rocket.
61. 3:42Over a trillion of us now, [music] so we
62. 3:44build on the sea.
63. 3:47Oceans cover more than twice as much of
64. 3:49Earth as land does. Building on them
65. 3:51triples the room.
66. 3:57Now, a new problem, and it isn't room.
67. 4:00It's heat.
68. 4:02Every machine and every light gives off
69. 4:04heat. So does every person.
70. 4:07Even with perfectly clean power,
71. 4:10trillions of us warm the whole planet.
72. 4:14By 2640, the planet is 9° warmer and
73. 4:19still climbing.
74. 4:21So, we turn down the sun.
75. 4:25[music]
76. 4:30Daylight stays dim from now on and the
77. 4:33city lights never go off again.
78. 4:37The towers even grow fins to push their
79. 4:40heat out into the sky.
80. 4:46Land and sea are both covered, so the
81. 4:49city builds on top of itself.
82. 4:52Every new layer covers the whole planet.
83. 4:55[music] It's like adding another Earth.
84. 5:00The lower layers get parks under glowing
85. 5:03ceilings, painted like a sky, so nobody
86. 5:06feels buried.
87. 5:14Down here, the ground hasn't seen the
88. 5:16sky in centuries.
89. 5:25It's clean and everything still works.
90. 5:28There's simply no room left.
91. 5:32Even with the sun fully [music] shaded,
92. 5:34Earth can't get rid of any more heat.
93. 5:37The planet is full.
94. 5:42Rockets were always too slow. No fleet
95. 5:46could ever move trillions of people.
96. 5:49So, people ride the elevator instead.
97. 5:51The trip to the top takes about a week
98. 5:54at highway speed.
99. 6:04Every city on Earth grown into one.
100. 6:10Around the middle, a ring of cities is
101. 6:12built in orbit.
102. 6:21Mars has had cities since the 2100s, but
103. 6:24a full Mars holds only about 3 years of
104. 6:27growth.
105. 6:30So, planets alone will never be enough.
106. 6:36The Moon and Mars end up as crowded as
107. 6:39Earth.
108. 6:46Even Jupiter's moons only buy a few more
109. 6:48years.
110. 6:56So, we build our own worlds.
111. 6:59Spinning cities, each one made out of an
112. 7:02asteroid.
113. 7:09By the year 3750, the asteroid belt is
114. 7:13gone. All of it became homes.
115. 7:20Then, we run out of things to build
116. 7:22with.
117. 7:23So, we take a whole planet apart.
118. 7:32Mercury is rebuilt piece by piece into
119. 7:35homes circling the Sun.
120. 7:40By the year 4250, there are more people
121. 7:43than grains of sand on every beach on
122. 7:46Earth.
123. 7:54Around the year 5100, the Sun is wrapped
124. 7:57in homes. Its light is all being used by
125. 8:01people.
126. 8:04By now, all of the people together weigh
127. 8:07more than the Earth.
128. 8:11And we're still growing.
129. 8:15So, where do we go next? If you want
130. 8:17part two, subscribe so you don't miss
131. 8:20it. And let me know in the comments if
132. 8:21you'd like to see that.