This Is How the World Ends According to Science — Transcript

Full transcript

1. 0:00- I'm gonna show you a graph
2. 0:01that the federal government doesn't want you to see.
3. 0:04For decades NOAA tracked the rising cost
4. 0:07of climate disasters in the United States.
5. 0:09Their billion-dollar disasters graph showed
6. 0:11how often extreme weather events caused catastrophic damage.
7. 0:15Then in 2025, funding for those updates was cut
8. 0:20and it wasn't an isolated decision.
9. 0:22The Trump administration has been removing information about
10. 0:26all sorts of inconvenient truths,
11. 0:28but studying severe climate scenarios has actually been
12. 0:31unpopular for a long time.
13. 0:34- Soon as you talk about any kind
14. 0:35of extreme risk in climate change, you are a doomer.
15. 0:37You are an a alarmist.
16. 0:38- And this matters. In recent years,
17. 0:40the most likely warming projections have come down thanks
18. 0:44to the rapid pace of renewable energy adoption.
19. 0:46But future progress is far from guaranteed.
20. 0:49- Most countries don't actually have the tools
21. 0:51to meet their climate targets and pledges.
22. 0:53- We've spent a lot of time on this show looking at
23. 0:55how progress is made,
24. 0:57but given the current reality, we need to understand
25. 0:59what happens at the upper ranges of warming projections.
26. 1:03And it's not the warming alone that puts us at risk.
27. 1:06- A world of three degrees
28. 1:07of warming in which you also have large levels
29. 1:10of inequality, geopolitical strife
30. 1:12and conflict, a lack of trust in public institutions,
31. 1:14and a huge amount of misinformation. That is
32. 1:16a world which may actually result in catastrophe.
33. 1:19- Luke studies what caused past civilizations to collapse,
34. 1:23how climate contributed,
35. 1:24and what we can learn about the risk today.
36. 1:27So in this episode, we're gonna learn
37. 1:28how the world plausibly ends.
38. 1:30According to science,
39. 1:32- 18% isn't exactly a small chance.
40. 1:35You're not gonna walk onto an airplane.
41. 1:36If there's an 18% chance of it crashing.
42. 1:40- You definitely wouldn't step on that plane
43. 1:42because you watch Weathered.
44. 1:44And if you wanna support the show while looking great,
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49. 1:57ask questions, suggest episodes and more.
50. 2:00The link is in the description.
51. 2:02In most high stakes fields.
52. 2:04Studying the worst case scenario is normal.
53. 2:07In medicine, aviation, nuclear engineering,
54. 2:09understanding everything that could go wrong isn't seen
55. 2:13as pessimism, but rather basic risk management.
56. 2:16- Whenever we try to deal with any kind
57. 2:18of risk management problem, we always think
58. 2:20through the worst case scenarios.
59. 2:22You don't engineer a car
60. 2:23and then not test it in a high speed crash.
61. 2:25You always look at the worst case scenario
62. 2:27whenever you're doing good risk management.
63. 2:29That is particularly true in conditions of deep uncertainty,
64. 2:32- But when it comes to the most consequential system
65. 2:35of all, earth's climate, we just don't like to talk about it.
66. 2:39- We've actually done text mining of IPCC reports to look at
67. 2:42how frequently different temperature scenarios are used,
68. 2:45and what we see is across all IPCC reports over the last
69. 2:49couple of decades, high-end warming scenarios are
70. 2:51substantially underrepresented compared
71. 2:53to low degree ones like 1.5 and two degree Celsius.
72. 2:57- So let's talk about it.
73. 2:58What is the worst case scenario and how do we avoid it?
74. 3:03- Under current policies, we are likely
75. 3:05to have a temperature rise somewhere between 2.6
76. 3:09to 2.9 degrees Celsius by the end of the century,
77. 3:12but that's the very likely range.
78. 3:13There's actually a much larger range.
79. 3:16- That around three degrees estimate makes a couple
80. 3:19big assumptions.
81. 3:20First, that the policies
82. 3:22and promises made under the 2016 Paris Climate Agreement are
83. 3:26broadly followed, and that requires strong political will
84. 3:29and global cooperation.
85. 3:31- In the long term, we don't really know
86. 3:33how the world's gonna look geopolitically,
87. 3:35- So we can't rule out a world with worse climate policy,
88. 3:38but there's another source of uncertainty
89. 3:40that's out of our hands.
90. 3:42Climate sensitivity is a measure of
91. 3:44how much the earth warms in response
92. 3:47to an increase in carbon dioxide,
93. 3:49and that alone could tip us into a very different world.
94. 3:53- Climate sensitivity could be far in excess
95. 3:55of three degrees
96. 3:56because the planet basically just doesn't work in the way
97. 3:59that we might've thought it does.
98. 4:01- We know it will be significantly warmer in the future,
99. 4:04but the further we look out, the more difficult it gets
100. 4:07to say exactly how much warmer.
101. 4:10According to current policies, we're on track
102. 4:12to reach approximately 670 parts per million
103. 4:16of carbon dioxide by the end of the century.
104. 4:19- Even if we only have 560, there'd be an 18% chance
105. 4:23that we go above 4.5 degrees Celsius.
106. 4:26- We haven't seen temperatures
107. 4:28that high in about 15 million years when sea levels were
108. 4:33tens of meters higher than today.
109. 4:35And at that level of warming, many
110. 4:37of Earth's major climate systems would either cross their
111. 4:41tipping points or be pushed into severe risk.
112. 4:44So not great.
113. 4:46- 18% isn't exactly a small chance you're not gonna walk
114. 4:50onto an airplane if there's an 18% chance of it crashing.
115. 4:54- It would take the world a long time to reach
116. 4:57that new far hotter state.
117. 4:59But when you take into account the complexities
118. 5:02of human behavior, the timeline can speed up dramatically
119. 5:06because in addition to heating the planet,
120. 5:08climate change destabilizes the systems we most depend on
121. 5:12both the natural systems and the human ones.
122. 5:16And when those systems come under stress at the same time
123. 5:19history shows they can fail very quickly.
124. 5:22Laurie compares this system failure
125. 5:23to a ship navigating a storm.
126. 5:26- When you are a crew on a ship trying your best to sail
127. 5:29around a storm, one of the things at the forefront
128. 5:31of your mind is protecting your crew's ability
129. 5:34to navigate while also handling the
130. 5:37worsting impacts of the storm.
131. 5:38And that can go one of two ways.
132. 5:39You can manage to allocate your resources and your attention
133. 5:43and maintain morale so that you are still able
134. 5:45to navigate while the worst of the storm rains down on you.
135. 5:48We could go the other way where you become so overwhelmed
136. 5:51that you fail to navigate
137. 5:53and then you drift further into the storm
138. 5:55and ultimately you are overwhelmed.
139. 5:56- This what researchers call derailment risk,
140. 6:00and it's one of the fastest ways climate change could push
141. 6:03the world towards collapse.
142. 6:04- Chaos caused by climate extremes
143. 6:06and worsening consequences
144. 6:08of climate change could actually begin to get in the way
145. 6:10of acting on climate change.
146. 6:13- And we've already seen
147. 6:15what climate induced derailment looks like in practice.
148. 6:18- Back in 2010, Russia was hit by heatwave,
149. 6:21which decimated its crops of wheat.
150. 6:23Because of that, Russia introduced a serial export ban.
151. 6:27The price of staples in particular wheat globally went up.
152. 6:30That doubled food bank usage in the UK,
153. 6:32but it also seemed
154. 6:34to cause increased political strife in Egypt.
155. 6:38And interestingly enough, the rise in food prices
156. 6:41and the rise of the price in bread in Egypt corresponds
157. 6:43pretty well with the Arab Spring,
158. 6:46and of course with huge political upheaval.
159. 6:49- Climate stress on its own didn't cause the Arab Spring,
160. 6:53but it acted as an accelerant pushing fragile systems past
161. 6:57their breaking point and causing the collapse
162. 6:59of governments across the region.
163. 7:01We can see similar cascading risks emerging here in the
164. 7:04United States too after extreme rain
165. 7:07and prolonged drought in Los Angeles,
166. 7:09two fires burned 16,000 homes.
167. 7:12- Insurance is the critical thing
168. 7:14that underpins all of capitalism.
169. 7:16Basically, when you're in a situation
170. 7:17where climate extremes are playing out worse than you
171. 7:21thought, then basically the maths start to break down.
172. 7:24- The insurance industry has so far weathered the storm
173. 7:28by raising rates and dropping customers, but its future
174. 7:31and availability in the region are unclear.
175. 7:33- If insurance is no longer available,
176. 7:35then other financial services aren't available, right?
177. 7:37Just think of houses. If you can't insure a house,
178. 7:39you can't get a mortgage on a house.
179. 7:41- We don't know how many more natural
180. 7:42disasters like this our
181. 7:44insurance and economic systems can withstand,
182. 7:47but we can already see the derailment theory at play
183. 7:51where climate disasters make us less able
184. 7:53to take climate action.
185. 7:55- You have almost the biggest wake up call
186. 7:58that America has ever had on climate change.
187. 8:00But then at the same time, you had the then president-elect
188. 8:04of the United States saying that this wasn't
189. 8:06to do with climate change.
190. 8:07They basically said, look, climate change isn't
191. 8:09causing these disasters.
192. 8:10It's climate fanaticism that causes these disasters.
193. 8:13- Laurie believes this derailment risk could easily cause us
194. 8:17to spiral closer
195. 8:18and closer into the storm of climate change.
196. 8:21So all of this made me wonder,
197. 8:23how is this likely to play out?
198. 8:26And clearly our experts have been spending a lot
199. 8:28of time thinking about this, like a lot.
200. 8:32- Imagine it's the early 2030s
201. 8:35and climate change has only got worse
202. 8:37and the world is even less stable than it is today.
203. 8:40And then suddenly extreme cold hits northwestern Europe.
204. 8:45This is because a key bit
205. 8:47of the Atlantic circulations has collapsed something called
206. 8:50the North Atlantic Subpolar Gyre.
207. 8:52- The subpolar gyre is an important part of AMOC,
208. 8:55an enormous circulation system
209. 8:57that carries heat from the tropics to the northern latitudes
210. 9:00and regulates global weather.
211. 9:02- What then happens is that part of the world
212. 9:04then becomes very unstable.
213. 9:05That then leads to a set of big corrections of panics,
214. 9:09basically in financial markets
215. 9:10because they didn't anticipate this wild card happening.
216. 9:13And it leads to a bit
217. 9:15of a financial crisis across the Euro-Atlantic area
218. 9:18that spreads to the rest of the world,
219. 9:19causing lots of destabilization.
220. 9:21- And if the subpolar gyre collapsed,
221. 9:23it would very likely be a warning
222. 9:24sign for the rest of the AMOC.
223. 9:26But by this point,
224. 9:27the world is already derailed politically, economically,
225. 9:31socially, and that makes responding
226. 9:34to a new enormous threat, far harder.
227. 9:37- Fast forward a number of years,
228. 9:39and the full circulation then collapses.
229. 9:41It doesn't just make Europe much colder,
230. 9:42therefore messing up major food growing regions in Europe.
231. 9:45It also disrupts the major monsoons globally,
232. 9:49including over India and Pakistan.
233. 9:52- And increased tensions between India
234. 9:55and Pakistan is something we really don't want.
235. 9:58- These two countries are both nuclear armed.
236. 9:59They have a history of hostility between each other
237. 10:02and they share a water resource, a water resource
238. 10:05that is gonna be drying up due to climate change.
239. 10:10- Any nuclear exchange, even a limited one, could trigger
240. 10:13what scientists call nuclear winter.
241. 10:16This occurs when nuclear explosions cause so many cities
242. 10:19to burn that soot injected into the atmosphere,
243. 10:22blocks sunlight and triggers
244. 10:24widespread crop failure
245. 10:26and mass starvation. Even just a regional nuclear war,
246. 10:30could kill around 2 billion people, mostly through famine
247. 10:34and a larger full scale nuclear war looks pretty much like
248. 10:38the end of the world with over 5 billion deaths,
249. 10:42and that's a conservative estimate.
250. 10:49During the Cold War, we were able
251. 10:51to avoid all out nuclear war once the cascading
252. 10:54impacts it would have
253. 10:55were actually studied and widely understood.
254. 10:58Once we understood that a nuclear war would mean game over.
255. 11:03The idea of nuclear deterrence became a priority.
256. 11:06And in the same way, understanding the worst case scenario
257. 11:09of climate change, which also looks a whole lot like the end
258. 11:13of the world, could be the very thing that saves us
259. 11:17because the more clearly we see the climate end game,
260. 11:21the better our chances of never reaching it.
261. 11:23In our next episode of Weathered,
262. 11:25we will look at the solutions
263. 11:26that can help prevent the worst case scenarios
264. 11:29we've been talking about.
265. 11:30And if you'd like to see extended interviews
266. 11:32with our experts, Luke
267. 11:33and Laurie, check 'em out on our Patreon page.
268. 11:36Let us know what you think about this
269. 11:37episode in the comments.
270. 11:38And as always, we'll see you next time on Weathered.