1 00:00:01,266 --> 00:00:03,566 -Very frightening moments unfolding in eastern Japan 2 00:00:03,600 --> 00:00:06,333 along the Kinugawa River. 3 00:00:06,366 --> 00:00:08,200 -Japan has been pounded with heavy rain 4 00:00:08,233 --> 00:00:09,933 for two days in a row. 5 00:00:09,966 --> 00:00:13,866 This is the 18th typhoon to hit Japan this year. 6 00:00:13,900 --> 00:00:16,300 -September 2015. 7 00:00:16,333 --> 00:00:19,366 20 inches of rain pelts down on Joso City 8 00:00:19,400 --> 00:00:22,133 just outside Tokyo, Japan. 9 00:00:22,166 --> 00:00:23,766 The river that flows through the city 10 00:00:23,800 --> 00:00:27,100 can't contain this unprecedented rainfall. 11 00:00:27,133 --> 00:00:30,166 The river floods, and 65,000 people 12 00:00:30,200 --> 00:00:32,900 find themselves trapped in a watery nightmare. 13 00:00:32,933 --> 00:00:37,100 ♪♪ 14 00:00:37,133 --> 00:00:40,866 This, despite the fact that Tokyo has the most advanced 15 00:00:40,900 --> 00:00:42,766 flood prevention system in the world. 16 00:00:42,800 --> 00:00:46,000 -Japan is prone to so many different types 17 00:00:46,033 --> 00:00:47,366 of natural disasters, 18 00:00:47,400 --> 00:00:49,966 including the flooding and potential for mud slides 19 00:00:50,000 --> 00:00:51,933 that we are seeing right now. 20 00:00:51,966 --> 00:00:53,800 -But that system did not anticipate 21 00:00:53,833 --> 00:00:55,933 the changes this century brings -- 22 00:00:55,966 --> 00:00:57,766 rising sea levels and stronger, 23 00:00:57,800 --> 00:01:01,333 more frequent rainstorms than have ever been recorded. 24 00:01:03,600 --> 00:01:05,000 -[ Speaking Japanese ] 25 00:01:05,033 --> 00:01:07,766 -Tokyo's defense line is constructed to endure 26 00:01:07,800 --> 00:01:11,400 a certain amount of rain. 27 00:01:11,433 --> 00:01:13,333 The reality is the embankment 28 00:01:13,366 --> 00:01:16,366 is not strong enough to withstand such force. 29 00:01:19,233 --> 00:01:20,966 -[ Screams ] [ Helicopter blades whirring ] 30 00:01:21,000 --> 00:01:24,100 -The world's great cities face threats 31 00:01:24,133 --> 00:01:26,666 they have never before encountered. 32 00:01:26,700 --> 00:01:27,733 New York. 33 00:01:27,766 --> 00:01:29,233 Tokyo. 34 00:01:29,266 --> 00:01:30,533 London. 35 00:01:30,566 --> 00:01:32,133 Miami. 36 00:01:32,166 --> 00:01:35,300 The threats come from the sea... 37 00:01:35,333 --> 00:01:36,633 from above... 38 00:01:36,666 --> 00:01:38,300 and from below. 39 00:01:38,333 --> 00:01:41,733 These are the problems and their solutions... 40 00:01:41,766 --> 00:01:47,700 ♪♪ 41 00:01:47,733 --> 00:01:49,933 ...for when the water comes. 42 00:01:49,966 --> 00:01:50,966 ♪♪ 43 00:02:01,000 --> 00:02:05,066 -More than 170,000 people received evacuation orders, 44 00:02:05,100 --> 00:02:09,666 and we know dozens of them were stranded in their homes, 45 00:02:09,699 --> 00:02:11,700 even a man holding onto a light pole 46 00:02:11,733 --> 00:02:13,866 waving for the Japanese military helicopters 47 00:02:13,900 --> 00:02:16,400 to come and rescue him. 48 00:02:16,433 --> 00:02:18,833 -From June to October, 49 00:02:18,866 --> 00:02:22,566 an average of 20 typhoons approach Japan each year. 50 00:02:24,433 --> 00:02:28,866 But the typhoon that hit Joso City in September 2015 51 00:02:28,900 --> 00:02:30,133 was different. 52 00:02:30,166 --> 00:02:32,200 The area had seen stronger typhoons, 53 00:02:32,233 --> 00:02:35,800 but never before had the rain fallen so hard. 54 00:02:35,833 --> 00:02:37,966 [ Birds chirping ] 55 00:02:41,400 --> 00:02:42,533 [ Door closes ] 56 00:02:42,566 --> 00:02:44,833 -[ Speaking Japanese ] 57 00:02:51,433 --> 00:02:54,533 ♪♪ 58 00:02:54,566 --> 00:02:56,566 [ Speaking Japanese ] 59 00:02:56,600 --> 00:02:59,066 -This is the Kinu River. 60 00:02:59,100 --> 00:03:02,300 In Chinese letters, the name is spelled as angry demon. 61 00:03:04,400 --> 00:03:07,166 -[ Speaking Japanese ] 62 00:03:07,200 --> 00:03:09,966 -My father-in-law was also here. 63 00:03:10,000 --> 00:03:12,833 He came with me because he was worried. 64 00:03:12,866 --> 00:03:14,833 And as soon as he said, "Watch out!" 65 00:03:14,866 --> 00:03:17,200 the water came rushing in. 66 00:03:17,233 --> 00:03:20,666 -[ Speaking Japanese ] 67 00:03:20,700 --> 00:03:23,566 -Hiromi Shinozaki and her father-in-law 68 00:03:23,600 --> 00:03:27,166 were among the people swept away in the sudden deluge. 69 00:03:27,200 --> 00:03:31,933 They clung to a floating piece of timber to avoid drowning. 70 00:03:31,966 --> 00:03:34,100 Torrential waters washed everything away 71 00:03:34,133 --> 00:03:37,133 in residential neighborhoods. 72 00:03:37,166 --> 00:03:39,800 Hiromi was one of dozens of stranded residents 73 00:03:39,833 --> 00:03:44,633 rescued by helicopters that day, as these people were. 74 00:03:46,066 --> 00:03:48,800 -[ Speaking Japanese ] 75 00:03:48,833 --> 00:03:51,766 -Holding onto the timber, we hoped that as long 76 00:03:51,800 --> 00:03:54,500 as our faces were above the surface of the water, 77 00:03:54,533 --> 00:03:56,200 we would be okay. 78 00:03:56,233 --> 00:03:58,500 We held on as best we could. 79 00:03:58,533 --> 00:04:01,033 But we weren't able to keep a hold on it, 80 00:04:01,066 --> 00:04:03,266 so we had to swim for our lives. 81 00:04:06,200 --> 00:04:09,533 -They finally made it to shore where they were still trapped. 82 00:04:09,566 --> 00:04:17,133 ♪♪ 83 00:04:17,166 --> 00:04:20,733 [ Announcement in Japanese over P.A. system ] 84 00:04:20,766 --> 00:04:22,400 [ Siren wails ] 85 00:04:22,433 --> 00:04:23,700 -[ Speaking Japanese ] 86 00:04:23,733 --> 00:04:27,233 -People were stuck and needed help everywhere. 87 00:04:27,266 --> 00:04:30,533 They were waving to helicopters, calling for help. 88 00:04:30,566 --> 00:04:35,133 -[ Speaking Japanese ] 89 00:04:35,166 --> 00:04:38,800 [ 90 00:04:35,166 --> 00:04:38,800 Helicopter blades whirring 91 00:04:35,166 --> 00:04:38,800 ] 92 00:04:40,333 --> 00:04:42,700 -[ Speaking Japanese ] 93 00:04:42,733 --> 00:04:44,533 -They were hovering above us. 94 00:04:44,566 --> 00:04:50,066 One rescuer came down, but because of the fierce current, 95 00:04:50,100 --> 00:04:52,366 he got washed away. 96 00:04:52,400 --> 00:04:54,900 -[ Speaking Japanese ] 97 00:04:54,933 --> 00:04:57,733 -I tried to hold on in spite of the strong wind. 98 00:04:57,766 --> 00:05:01,266 It was really hard, but they finally pulled me up to safety. 99 00:05:03,233 --> 00:05:06,133 -Her father in law was also rescued. 100 00:05:06,166 --> 00:05:10,100 In fact, only two people died. 101 00:05:10,133 --> 00:05:13,100 7,000 homes and buildings in Joso City 102 00:05:13,133 --> 00:05:17,033 were damaged or destroyed in that flood. 103 00:05:17,066 --> 00:05:21,566 Joso City was hit with 20 inches of rain in 24 hours. 104 00:05:21,600 --> 00:05:25,400 If that much rain had fallen on Tokyo, just 30 miles away, 105 00:05:25,433 --> 00:05:28,633 the results would have been even more catastrophic. 106 00:05:28,666 --> 00:05:31,166 ♪♪ 107 00:05:31,200 --> 00:05:33,433 Tokyo is the largest city in the world 108 00:05:33,466 --> 00:05:38,033 with 38 million people in the Greater Tokyo Area. 109 00:05:38,066 --> 00:05:41,700 Without this vital city, Japan's economy would collapse, 110 00:05:41,733 --> 00:05:45,900 which is why protecting this city matters. 111 00:05:45,933 --> 00:05:49,666 -Tokyo is like the Rolls-Royce of city and engineering. 112 00:05:49,700 --> 00:05:52,366 It has most of the high tech system 113 00:05:52,400 --> 00:05:54,233 that you can find in the world. 114 00:05:54,266 --> 00:05:57,233 -Dr. Christopher Gomez of Kobe University studies 115 00:05:57,266 --> 00:06:01,200 the threat Tokyo faces from the rising sea. 116 00:06:01,233 --> 00:06:04,766 -Tokyo is the economic engine of Japan, 117 00:06:04,800 --> 00:06:08,700 and Japan is one of the major engine of the world economy. 118 00:06:08,733 --> 00:06:10,866 So all of this is interconnected. 119 00:06:10,900 --> 00:06:14,033 If you start to have a major flood on Tokyo, 120 00:06:14,066 --> 00:06:17,766 we're all going to pay it, and very directly, actually. 121 00:06:17,800 --> 00:06:19,966 [ Birds crying ] 122 00:06:20,000 --> 00:06:24,833 -[ Speaking Japanese ] 123 00:06:24,866 --> 00:06:27,400 -Many insurance companies around the world, 124 00:06:27,433 --> 00:06:29,400 such as Lloyd's or Swiss Re, 125 00:06:29,433 --> 00:06:30,700 have assessed Tokyo 126 00:06:30,733 --> 00:06:33,700 as the most dangerous city in the world. 127 00:06:33,733 --> 00:06:35,300 And in their assessment, 128 00:06:35,333 --> 00:06:38,966 they say Tokyo's preparation for flooding is not enough. 129 00:06:39,000 --> 00:06:48,433 ♪♪ 130 00:06:48,466 --> 00:06:51,633 -[ Speaking Japanese ] 131 00:06:51,666 --> 00:06:54,700 -So the true risk to Tokyo lies in people believing 132 00:06:54,733 --> 00:06:57,766 that they are protected and safe 133 00:06:57,800 --> 00:07:00,200 when they are not at all. 134 00:07:00,233 --> 00:07:03,566 ♪♪ 135 00:07:03,600 --> 00:07:05,833 -Understanding Tokyo begins with a picture 136 00:07:05,866 --> 00:07:09,200 of the city's relationship with the sea. 137 00:07:09,233 --> 00:07:11,533 It sits on the shore of Tokyo Bay, 138 00:07:11,566 --> 00:07:14,900 which connects to the Pacific Ocean. 139 00:07:14,933 --> 00:07:17,433 To the city's East is the Edo River, 140 00:07:17,466 --> 00:07:21,200 and its western border runs along the Tama River. 141 00:07:21,233 --> 00:07:24,633 In all, 107 rivers run through the city. 142 00:07:27,500 --> 00:07:30,566 Water is the heart and veins of Tokyo. 143 00:07:30,600 --> 00:07:35,000 ♪♪ 144 00:07:35,033 --> 00:07:37,800 Though some areas are below sea level, 145 00:07:37,833 --> 00:07:41,733 the city sits 130 feet above it on average, 146 00:07:41,766 --> 00:07:44,700 compared with New York at just over 30 feet 147 00:07:44,733 --> 00:07:47,733 or Miami at 6 feet, 148 00:07:47,766 --> 00:07:51,133 Tokyo's higher ground suggests relative safety 149 00:07:51,166 --> 00:07:55,300 as oceans rise around the world. 150 00:07:55,333 --> 00:07:56,900 But the difference with Tokyo 151 00:07:56,933 --> 00:07:59,366 is the wide range of threats it faces -- 152 00:07:59,400 --> 00:08:01,533 more than any other city on the planet. 153 00:08:01,566 --> 00:08:03,833 [ People scream ] 154 00:08:03,866 --> 00:08:06,066 Earthquakes. 155 00:08:06,100 --> 00:08:09,233 Tsunamis. 156 00:08:09,266 --> 00:08:13,233 A unique quicksand phenomenon called liquefaction. 157 00:08:13,266 --> 00:08:15,366 And, above all... [ Thunder rumbles ] 158 00:08:15,400 --> 00:08:19,133 ...powerful rainstorms that come with typhoons. 159 00:08:19,166 --> 00:08:24,066 Typhoons pound Tokyo with rain from June to October every year. 160 00:08:24,100 --> 00:08:27,233 The city gets 60 inches of rain per year, 161 00:08:27,266 --> 00:08:30,900 three times the legendary rainfall of London. 162 00:08:30,933 --> 00:08:32,633 But this isn't new. 163 00:08:32,666 --> 00:08:37,400 ♪♪ 164 00:08:37,433 --> 00:08:41,299 -32 inches of rain deluges heavily populated Kyushu, 165 00:08:41,333 --> 00:08:43,933 Japan's southernmost major island. 166 00:08:43,966 --> 00:08:46,000 Low-lying areas where cities and towns 167 00:08:46,033 --> 00:08:48,333 are concentrated were hardest hit. 168 00:08:48,366 --> 00:08:49,666 The record torrents brought 169 00:08:49,700 --> 00:08:51,900 the island's streams and rivers to overflow, 170 00:08:51,933 --> 00:08:54,033 a surging tide of destruction 171 00:08:54,066 --> 00:08:56,233 swept through the area near Nagasaki, 172 00:08:56,266 --> 00:08:59,633 leaving in its wake a sea of mud, debris, and death. 173 00:09:02,866 --> 00:09:06,500 -In the half century since that 1954 deluge, 174 00:09:06,533 --> 00:09:08,566 the heavy precipitation from these storms 175 00:09:08,600 --> 00:09:10,866 has become 30 percent greater 176 00:09:10,900 --> 00:09:13,033 and more intense than ever before 177 00:09:13,066 --> 00:09:15,833 in the city's recorded history. 178 00:09:15,866 --> 00:09:20,200 In 2018, typhoon Maria strikes Japan's southwest, 179 00:09:20,233 --> 00:09:23,066 bringing the country's worst flooding and mudslides 180 00:09:23,100 --> 00:09:25,033 in 35 years. 181 00:09:25,066 --> 00:09:27,533 Millions of people are displaced from their homes, 182 00:09:27,566 --> 00:09:30,766 throwing Japan into a state of emergency. 183 00:09:30,800 --> 00:09:32,733 Over 200 people are dead, 184 00:09:32,766 --> 00:09:36,100 and the damage is estimated in the billions of dollars 185 00:09:36,133 --> 00:09:40,233 with roads, bridges, and railways destroyed. 186 00:09:40,266 --> 00:09:43,066 The people of Japan reel from the disaster, 187 00:09:43,100 --> 00:09:45,333 but fear worse is still to come 188 00:09:45,366 --> 00:09:47,700 from even more powerful typhoons. 189 00:09:49,833 --> 00:09:51,233 -[ Speaking Japanese ] 190 00:09:51,266 --> 00:09:55,366 -The behavior of the typhoons around Japan in recent years 191 00:09:55,400 --> 00:09:57,300 shows that they are clearly different 192 00:09:57,333 --> 00:09:58,966 from the ones in the past. 193 00:09:59,000 --> 00:10:03,000 -Dr. Tomoya Shibayama has been studying typhoons 194 00:10:03,033 --> 00:10:06,166 and their rainfall for nearly 40 years. 195 00:10:06,200 --> 00:10:08,433 -[ Speaking Japanese ] 196 00:10:08,466 --> 00:10:11,366 -Until recently, it was common for a typhoon 197 00:10:11,400 --> 00:10:15,133 to lose its intensity as it got closer to Japan 198 00:10:15,166 --> 00:10:19,400 because the sea surface temperature was colder. 199 00:10:19,433 --> 00:10:21,966 One of the recent changes is that typhoons 200 00:10:22,000 --> 00:10:24,566 continue to grow as they approach Japan 201 00:10:24,600 --> 00:10:27,833 because the sea surface temperature is warmer, 202 00:10:27,866 --> 00:10:30,866 so the typhoon does not lose its power. 203 00:10:34,166 --> 00:10:36,866 -Sea surface temperatures around Japan are expected 204 00:10:36,900 --> 00:10:42,300 to rise by almost 4 degrees Fahrenheit by 2100. 205 00:10:42,333 --> 00:10:44,800 This means storms will increase in intensity 206 00:10:44,833 --> 00:10:47,400 as they approach the island nation. 207 00:10:50,200 --> 00:10:52,200 -[ Speaking Japanese ] 208 00:10:52,233 --> 00:10:56,433 -Until now, we have been referring to the Ise Bay Typhoon 209 00:10:56,466 --> 00:10:58,633 as our benchmark. 210 00:11:00,066 --> 00:11:04,266 -The Ise Bay Typhoon is also known as Typhoon Vera. 211 00:11:04,300 --> 00:11:08,000 In 1959, it hit Japan with 20 inches of rain 212 00:11:08,033 --> 00:11:10,933 and a 13-foot storm surge. 213 00:11:10,966 --> 00:11:13,666 Some 5,000 people died, and Vera did 214 00:11:13,700 --> 00:11:16,066 over $2 billion of damage -- 215 00:11:16,100 --> 00:11:19,866 Japan's deadliest and costliest typhoon. 216 00:11:19,900 --> 00:11:21,700 -[ Speaking Japanese ] 217 00:11:21,733 --> 00:11:24,600 -But in the future, I think we need to be prepared 218 00:11:24,633 --> 00:11:27,066 for even bigger storm surges. 219 00:11:28,666 --> 00:11:31,166 ♪♪ 220 00:11:31,200 --> 00:11:33,266 -Flooding is a problem Tokyo has endured 221 00:11:33,300 --> 00:11:35,066 for four centuries. 222 00:11:35,100 --> 00:11:37,800 In the 20th Century after Typhoon Vera, 223 00:11:37,833 --> 00:11:41,400 the city found solutions through elaborate engineering. 224 00:11:41,433 --> 00:11:42,966 Water is diverted to rivers 225 00:11:43,000 --> 00:11:45,133 through a series of canals and pipes, 226 00:11:45,166 --> 00:11:48,700 which all flow back into the sea. 227 00:11:48,733 --> 00:11:51,466 And the city's main rivers are contained by levees, 228 00:11:51,500 --> 00:11:52,866 which have been built up over decades 229 00:11:52,900 --> 00:11:57,100 to prevent flooding in low-lying areas. 230 00:11:57,133 --> 00:11:58,866 -[ Speaking Japanese ] 231 00:11:58,900 --> 00:12:01,800 -The limit of the Arakawa River's defense 232 00:12:01,833 --> 00:12:06,600 is rainfall of 20 inches in 3 days. 233 00:12:06,633 --> 00:12:09,100 The levees are built based on such a plan. 234 00:12:11,166 --> 00:12:14,000 [ Helicopter blades whirring ] 235 00:12:14,033 --> 00:12:17,333 So if the same kind of rain that fell on the Kinu River 236 00:12:17,366 --> 00:12:19,666 would fall on Tokyo, 237 00:12:19,700 --> 00:12:22,166 I have to say that the reality is, 238 00:12:22,200 --> 00:12:26,466 the embankment is not strong enough to endure such force. 239 00:12:26,500 --> 00:12:28,433 -[ Speaking Japanese ] 240 00:12:28,466 --> 00:12:32,000 -Tokyo is defenseless against such rainfall. 241 00:12:34,600 --> 00:12:36,066 -[ Speaking Japanese ] 242 00:12:36,100 --> 00:12:38,166 -The moment the embankment breaks, 243 00:12:38,200 --> 00:12:43,000 a high wave, like a tsunami, would hit residential areas. 244 00:12:44,733 --> 00:12:47,933 ♪♪ 245 00:12:47,966 --> 00:12:52,300 -Stronger, wetter typhoons are just one of Tokyo's problems. 246 00:12:52,333 --> 00:12:55,533 Another is tsunamis, triggered by earthquakes. 247 00:12:57,766 --> 00:13:00,800 Japan is situated on the Pacific Ring of Fire, 248 00:13:00,833 --> 00:13:02,800 a tectonic plate that is responsible 249 00:13:02,833 --> 00:13:05,700 for 90 percent of the world's earthquakes. 250 00:13:05,733 --> 00:13:07,833 Japan records more of them every year 251 00:13:07,866 --> 00:13:12,366 than any other country on earth -- 1,500 earthquakes. 252 00:13:12,400 --> 00:13:13,866 With sea levels rising, 253 00:13:13,900 --> 00:13:17,466 the aftershocks of tsunamis are deadlier than ever. 254 00:13:19,500 --> 00:13:22,800 In 2011, an earthquake triggered a tsunami, 255 00:13:22,833 --> 00:13:24,000 leading to meltdown 256 00:13:24,033 --> 00:13:27,033 at the Fukushima Nuclear Power Plant. 257 00:13:27,066 --> 00:13:28,866 The tsunami set off the worst 258 00:13:28,900 --> 00:13:31,466 nuclear disaster since Chernobyl, 259 00:13:31,500 --> 00:13:34,733 and it woke the world up to the constant danger Japan faces 260 00:13:34,766 --> 00:13:36,233 from the sea. 261 00:13:36,266 --> 00:13:40,033 -[ Speaking Japanese ] 262 00:13:40,066 --> 00:13:42,666 -People realized that they had to recognize 263 00:13:42,700 --> 00:13:45,133 the destructive power of the water. 264 00:13:45,166 --> 00:13:47,866 If the river embankment in Tokyo breaks, 265 00:13:47,900 --> 00:13:50,266 residential areas would be hit by waves 266 00:13:50,300 --> 00:13:53,866 as large as the tsunami which destroyed Fukushima. 267 00:13:53,900 --> 00:13:55,500 [ Helicopter blades whirring ] 268 00:13:55,533 --> 00:13:57,533 ♪♪ 269 00:13:57,566 --> 00:14:04,366 -The 2011 earthquake did impact Tokyo 150 miles away. 270 00:14:04,400 --> 00:14:09,233 Yoshitaka Udagawa owns an exotic fish shop in Urayasu, 271 00:14:09,266 --> 00:14:12,066 a city on Tokyo's outskirts. 272 00:14:12,100 --> 00:14:13,566 -[ Speaking Japanese ] 273 00:14:13,600 --> 00:14:17,500 -I felt a massive jolt with a giant thud. 274 00:14:17,533 --> 00:14:19,633 We have many earthquakes in Japan, 275 00:14:19,666 --> 00:14:22,800 so I thought, "It's an earthquake again." 276 00:14:22,833 --> 00:14:26,500 But I had never experienced such an intense earthquake. 277 00:14:26,533 --> 00:14:29,733 It continued, "Boom! Boom! Boom!" 278 00:14:29,766 --> 00:14:32,800 -Udagawa fled his store, 279 00:14:32,833 --> 00:14:35,733 into the street and the earthquake's fury. 280 00:14:35,766 --> 00:14:38,633 ♪♪ 281 00:14:38,666 --> 00:14:40,233 -[ Speaking Japanese ] 282 00:14:40,266 --> 00:14:42,600 -It was difficult to walk. 283 00:14:42,633 --> 00:14:47,633 The poles were really swaying in all directions. 284 00:14:47,666 --> 00:14:50,000 The ground was shaking. 285 00:14:50,033 --> 00:14:53,000 -[ Speaking Japanese ] 286 00:14:53,033 --> 00:14:55,966 -I continued walking 287 00:14:56,000 --> 00:14:58,766 and heard a noise when I got to this point. 288 00:15:02,566 --> 00:15:04,766 You see that dark part over there? 289 00:15:06,800 --> 00:15:10,933 There was something shooting out of it like oil blowing out. 290 00:15:10,966 --> 00:15:13,533 -[ Speaking Japanese ] 291 00:15:13,566 --> 00:15:20,033 ♪♪ 292 00:15:20,066 --> 00:15:23,566 -The water's gushing out everywhere. 293 00:15:23,600 --> 00:15:26,600 The ocean seems to be coming up. 294 00:15:26,633 --> 00:15:29,700 -The dark liquid gushing from the ground was not oil, 295 00:15:29,733 --> 00:15:31,600 but water and mud. 296 00:15:31,633 --> 00:15:34,833 A process called liquefaction was causing the groundwater 297 00:15:34,866 --> 00:15:37,200 to push up to the surface. 298 00:15:37,233 --> 00:15:40,500 About 10 percent of Tokyo is built on low-lying sediment 299 00:15:40,533 --> 00:15:42,366 along the city's coast. 300 00:15:42,400 --> 00:15:44,033 The shaking effect from the earthquakes 301 00:15:44,066 --> 00:15:47,566 creates a form of liquid earth, like quicksand. 302 00:15:47,600 --> 00:15:49,800 Liquefaction is now a regular side effect 303 00:15:49,833 --> 00:15:51,800 of earthquakes in Tokyo. 304 00:15:51,833 --> 00:15:56,133 -Under your feet, you have up to 125 meters of soft sediment 305 00:15:56,166 --> 00:15:57,700 mixed with water. 306 00:15:57,733 --> 00:15:59,333 The problem with it is 307 00:15:59,366 --> 00:16:02,233 that mixture between water and sediment, 308 00:16:02,266 --> 00:16:03,733 each time you have a shake, 309 00:16:03,766 --> 00:16:06,500 the water get expelled from the ground, 310 00:16:06,533 --> 00:16:09,200 so it leaves hole in the ground in some ways, 311 00:16:09,233 --> 00:16:11,500 and then the ground goes down. 312 00:16:11,533 --> 00:16:21,066 ♪♪ 313 00:16:21,100 --> 00:16:24,633 -Shinji Sassa of the Port and Airport Research Institute 314 00:16:24,666 --> 00:16:26,500 created a shake table to demonstrate 315 00:16:26,533 --> 00:16:30,100 the process of liquefaction in the laboratory. 316 00:16:30,133 --> 00:16:32,933 ♪♪ 317 00:17:01,200 --> 00:17:04,133 -3, 2, 1... 318 00:17:04,166 --> 00:17:06,366 Okay. 319 00:17:06,400 --> 00:17:08,733 [ Table whirring ] 320 00:17:12,800 --> 00:17:14,200 -So when you look at the map right here, 321 00:17:14,233 --> 00:17:16,733 you can see that all the blue areas here, 322 00:17:16,766 --> 00:17:18,666 this is already below sea level. 323 00:17:18,700 --> 00:17:19,866 We are minus one, 324 00:17:19,900 --> 00:17:22,233 minus two meters below sea level. 325 00:17:22,266 --> 00:17:24,800 And Tokyo is not any other city. 326 00:17:24,833 --> 00:17:26,900 You have a major quake waiting for you, 327 00:17:26,933 --> 00:17:30,900 so all of that can actually go down by an extra meter. 328 00:17:30,933 --> 00:17:32,300 What you have to remember 329 00:17:32,333 --> 00:17:34,733 is that all the sediments below the city, 330 00:17:34,766 --> 00:17:38,600 a lot of them are a mixture of water and sand, 331 00:17:38,633 --> 00:17:41,833 and once all this gets excited, you get liquefaction. 332 00:17:41,866 --> 00:17:43,333 The water comes out, 333 00:17:43,366 --> 00:17:46,366 and what remains is the land going down. 334 00:17:46,400 --> 00:17:49,433 -Liquefaction is a new phenomenon in Tokyo. 335 00:17:49,466 --> 00:17:52,900 It, too, is linked to the rising sea levels. 336 00:17:52,933 --> 00:17:55,366 -The groundwater of Tokyo is connected to the sea level, 337 00:17:55,400 --> 00:17:57,333 so if the sea level goes up, 338 00:17:57,366 --> 00:18:00,166 then the groundwater will also go up. 339 00:18:00,200 --> 00:18:03,233 It's like a pie chart -- we have been dividing that pie. 340 00:18:03,266 --> 00:18:06,666 So those slices can be the river floods. 341 00:18:06,700 --> 00:18:08,200 Another one can be 342 00:18:08,233 --> 00:18:10,000 the liquefaction during an earthquake 343 00:18:10,033 --> 00:18:11,533 that brings the land down. 344 00:18:11,566 --> 00:18:14,866 Another one can be the storm surge. 345 00:18:14,900 --> 00:18:17,966 Another one will be, again, the sea level rise. 346 00:18:18,000 --> 00:18:22,433 And all of those elements that are looked on separately 347 00:18:22,466 --> 00:18:25,066 will, at some point, happen together. 348 00:18:25,100 --> 00:18:30,133 ♪♪ 349 00:18:30,166 --> 00:18:33,366 -Tokyo has one last unique problem. 350 00:18:33,400 --> 00:18:37,600 Entire neighborhoods are slowly sinking below sea level. 351 00:18:37,633 --> 00:18:40,566 Decades of pumping ground water for domestic use 352 00:18:40,600 --> 00:18:44,033 has left massive cavities below the city's foundations, 353 00:18:44,066 --> 00:18:47,666 and some areas are now sinking. 354 00:18:47,700 --> 00:18:50,666 -100 years ago, Tokyo was just a village, 355 00:18:50,700 --> 00:18:53,433 just a few people, called Edo, actually. 356 00:18:53,466 --> 00:18:58,500 And during the 19th Century, this village became the capital. 357 00:18:58,533 --> 00:19:01,066 So on top of the marshlands, 358 00:19:01,100 --> 00:19:05,000 on top of silty sediment mixed with water, 359 00:19:05,033 --> 00:19:08,833 they started to drain this land and build this huge capital. 360 00:19:08,866 --> 00:19:11,533 But it means that underneath the ground, 361 00:19:11,566 --> 00:19:13,533 you still have the mud flats. 362 00:19:13,566 --> 00:19:17,933 What you have below your feet is a mixture of water and sediment. 363 00:19:17,966 --> 00:19:19,633 Until the 1960s, 364 00:19:19,666 --> 00:19:22,966 people used to drink water from the ground water, 365 00:19:23,000 --> 00:19:26,200 meaning that they pumped the water out of the ground. 366 00:19:26,233 --> 00:19:30,333 So where the water was, then just a void remains. 367 00:19:30,366 --> 00:19:34,400 So the land sinks slowly. 368 00:19:34,433 --> 00:19:36,466 -30 percent of Tokyo's population 369 00:19:36,500 --> 00:19:38,066 now lives below sea level, 370 00:19:38,100 --> 00:19:41,800 and some homes have sunk as much as 15 feet due to subsidence, 371 00:19:41,833 --> 00:19:43,866 the caving in of land. 372 00:19:43,900 --> 00:19:45,166 As sea levels rise, 373 00:19:45,200 --> 00:19:47,500 the gap between these low-lying neighborhoods 374 00:19:47,533 --> 00:19:51,733 and the waters above them becomes ever more dangerous. 375 00:19:51,766 --> 00:19:56,400 -[ Speaking Japanese ] 376 00:19:56,433 --> 00:19:59,633 -The sea level rise is now producing the same effect 377 00:19:59,666 --> 00:20:01,666 as the ground subsidence. 378 00:20:01,700 --> 00:20:03,866 -[ Speaking Japanese ] 379 00:20:03,900 --> 00:20:06,800 -The danger is getting greater and greater. 380 00:20:06,833 --> 00:20:11,966 -[ Speaking Japanese ] 381 00:20:12,000 --> 00:20:15,566 -You have a city which is just at the zero level, 382 00:20:15,600 --> 00:20:19,366 so any increase in sea level is already a problem. 383 00:20:19,400 --> 00:20:21,633 So this map here is the map of Tokyo. 384 00:20:21,666 --> 00:20:23,633 So what you can see in the white here 385 00:20:23,666 --> 00:20:25,700 is the bay where the water is, 386 00:20:25,733 --> 00:20:28,600 and everything else is supposed to be land. 387 00:20:28,633 --> 00:20:29,866 But if you look at it, 388 00:20:29,900 --> 00:20:32,066 you can see that all the blue areas here -- 389 00:20:32,100 --> 00:20:33,600 and they are blue for a good reason. 390 00:20:33,633 --> 00:20:36,766 It's because it's already below the sea level. 391 00:20:36,800 --> 00:20:42,066 If you add 50 centimeters of sea level, 392 00:20:42,100 --> 00:20:44,066 you can see that a large part of the city 393 00:20:44,100 --> 00:20:48,666 already, in red here, is under water. 394 00:20:48,700 --> 00:20:53,366 And then if you add 75 centimeters and one meter, 395 00:20:53,400 --> 00:20:56,700 you almost have 100 square kilometers of water 396 00:20:56,733 --> 00:20:58,066 covering your land. 397 00:20:58,100 --> 00:21:00,333 -If the sea rises by 3 feet, 398 00:21:00,366 --> 00:21:04,200 60 square miles of Tokyo will be submerged. 399 00:21:04,233 --> 00:21:08,366 Japan's problems are compounded by an economic challenge. 400 00:21:08,400 --> 00:21:11,200 Its population is expected to shrink by a third 401 00:21:11,233 --> 00:21:13,500 in the next half-century. 402 00:21:13,533 --> 00:21:16,833 In the past, a growing population and a booming economy 403 00:21:16,866 --> 00:21:18,466 helped pay for megaprojects 404 00:21:18,500 --> 00:21:21,500 to prevent and combat natural disasters. 405 00:21:21,533 --> 00:21:24,800 Those days are ending. 406 00:21:24,833 --> 00:21:26,833 40 percent of Japan's population 407 00:21:26,866 --> 00:21:30,900 is projected to be over age 64 by 2050. 408 00:21:30,933 --> 00:21:32,966 The country's birthrate is plummeting, 409 00:21:33,000 --> 00:21:35,666 and it isn't expected to rebound to present levels 410 00:21:35,700 --> 00:21:37,866 for another 45 years. 411 00:21:37,900 --> 00:21:41,700 -So, Japan has been very good at facing its issue so far. 412 00:21:41,733 --> 00:21:43,400 They've been working very hard on all of this. 413 00:21:43,433 --> 00:21:47,166 You have a lot of engineering systems that are top notch. 414 00:21:47,200 --> 00:21:50,600 But in a country where the population 415 00:21:50,633 --> 00:21:53,700 is increasingly aging 416 00:21:53,733 --> 00:21:57,266 and where money's going to be scarcer and scarcer, 417 00:21:57,300 --> 00:21:59,333 how do you maintain all the system? 418 00:21:59,366 --> 00:22:04,133 The population, which is aging, plus the climate change 419 00:22:04,166 --> 00:22:06,966 is a real ticking bomb for Tokyo. 420 00:22:07,000 --> 00:22:09,100 How do you build new dikes and new levees 421 00:22:09,133 --> 00:22:11,000 when you don't have the fund for it? 422 00:22:13,300 --> 00:22:15,133 So it's a real challenge. 423 00:22:17,500 --> 00:22:21,366 -Kamaishi is 350 miles up the coast from Tokyo. 424 00:22:21,400 --> 00:22:25,333 It's an extreme example of Japan's plummeting population. 425 00:22:25,366 --> 00:22:27,766 Less than 40,000 people live here, 426 00:22:27,800 --> 00:22:30,933 25,000 fewer than in 1980. 427 00:22:30,966 --> 00:22:34,700 The city is home to the largest seawall in the world. 428 00:22:35,800 --> 00:22:37,533 -[ Speaking Japanese ] 429 00:22:37,566 --> 00:22:40,333 -The north wall was 3,200 feet. 430 00:22:40,366 --> 00:22:42,966 The southern wall was 2,200 feet, 431 00:22:43,000 --> 00:22:47,066 and the part where the ships go through was 1,000 feet long, 432 00:22:47,100 --> 00:22:48,366 so as a whole, 433 00:22:48,400 --> 00:22:52,000 it was 6,500 feet -- over a mile long. 434 00:22:52,033 --> 00:22:54,200 -[ Speaking Japanese ] 435 00:22:54,233 --> 00:22:56,633 -Kamaishi's breakwater is constructed 436 00:22:56,666 --> 00:22:59,733 at a depth of 200 feet below the surface. 437 00:22:59,766 --> 00:23:03,433 It's in the Guinness Book of World Records. 438 00:23:03,466 --> 00:23:06,866 -The breakwater cost $1.6 billion 439 00:23:06,900 --> 00:23:09,666 and took three decades to complete. 440 00:23:09,700 --> 00:23:13,100 In 2009, the job was finally done. 441 00:23:13,133 --> 00:23:15,333 [ Sirens wail ] 442 00:23:15,366 --> 00:23:16,666 Just two years later... 443 00:23:16,700 --> 00:23:18,633 -[ Shouts in Japanese ] 444 00:23:18,666 --> 00:23:21,033 [ People scream ] 445 00:23:21,066 --> 00:23:25,366 -...Japan's tsunami crushed this marvel of engineering like a toy 446 00:23:25,400 --> 00:23:28,033 and swept through the town. 447 00:23:28,066 --> 00:23:31,666 The bodies of about 1,000 people were never found. 448 00:23:31,700 --> 00:23:33,433 [ Birds chirping ] 449 00:23:33,466 --> 00:23:38,466 Akiko Iwasaki runs a hotel outside Kamaishi. 450 00:23:38,500 --> 00:23:41,966 She witnessed the horrific 32-foot-high tidal flood 451 00:23:42,000 --> 00:23:44,633 that destroyed her city. 452 00:23:44,666 --> 00:23:47,766 She was also personally struck by tragedy. 453 00:23:47,800 --> 00:23:50,300 One of her relatives was among those killed. 454 00:23:50,333 --> 00:23:51,933 -[ Speaking Japanese ] 455 00:23:51,966 --> 00:23:54,533 -One of my family members tied herself to a pillar 456 00:23:54,566 --> 00:23:57,900 at the entrance of her house with a rope. 457 00:23:57,933 --> 00:24:00,300 She was a senior, and when the firefighters 458 00:24:00,333 --> 00:24:03,166 urged residents to evacuate, she probably didn't think 459 00:24:03,200 --> 00:24:07,033 the tsunami would come up that high. 460 00:24:07,066 --> 00:24:09,266 She didn't run away. 461 00:24:09,300 --> 00:24:11,700 When she was found, her son said that, 462 00:24:11,733 --> 00:24:14,433 in the time she took to tie herself to the pillar, 463 00:24:14,466 --> 00:24:17,333 she could have run to safety. 464 00:24:17,366 --> 00:24:19,666 ♪♪ 465 00:24:19,700 --> 00:24:21,566 -[ Screams in Japanese ] 466 00:24:21,600 --> 00:24:25,266 -Sadness turned to outrage. 467 00:24:25,300 --> 00:24:27,466 How could this expensive megaproject 468 00:24:27,500 --> 00:24:29,300 that was built to protect the city 469 00:24:29,333 --> 00:24:32,333 fail so catastrophically? 470 00:24:36,866 --> 00:24:39,533 The seawall is now being rebuilt. 471 00:24:39,566 --> 00:24:41,933 And how to make it certain not to fail again 472 00:24:41,966 --> 00:24:44,300 is Yussai Itoh's job. 473 00:24:44,333 --> 00:24:45,366 -[ Speaking Japanese ] 474 00:24:45,400 --> 00:24:47,633 -Since we're in the midst of construction, 475 00:24:47,666 --> 00:24:49,166 we see some different heights. 476 00:24:49,200 --> 00:24:51,766 However, they will be covered with concrete, 477 00:24:51,800 --> 00:24:53,566 and they will all be level. 478 00:24:56,300 --> 00:24:58,233 The tsunami came from offshore, 479 00:24:58,266 --> 00:25:00,733 crossed the mouth of the bay breakwater, 480 00:25:00,766 --> 00:25:02,766 and moved into the city. 481 00:25:05,100 --> 00:25:07,433 It was about 33 feet high. 482 00:25:07,466 --> 00:25:10,566 -[ Speaking Japanese ] 483 00:25:12,266 --> 00:25:14,233 -The seawall had been designed to withstand 484 00:25:14,266 --> 00:25:16,300 a wave of that height. 485 00:25:16,333 --> 00:25:18,300 The engineers who designed the seawall 486 00:25:18,333 --> 00:25:21,633 were determined to figure out why and how it failed 487 00:25:21,666 --> 00:25:23,633 with such loss of life. 488 00:25:23,666 --> 00:25:26,033 -[ Speaking Japanese ] 489 00:25:26,066 --> 00:25:29,300 -Before the tsunami in Northeastern Japan, 490 00:25:29,333 --> 00:25:33,800 we didn't understand exactly how barriers were destroyed. 491 00:25:33,833 --> 00:25:38,600 ♪♪ 492 00:25:38,633 --> 00:25:41,500 -In his hydraulics lab at Waseda University, 493 00:25:41,533 --> 00:25:45,533 Dr. Tomoya Shibayama is trying to solve the mystery. 494 00:25:45,566 --> 00:25:47,033 -[ Speaking Japanese ] 495 00:25:47,066 --> 00:25:49,200 -This is the simulator for the waves 496 00:25:49,233 --> 00:25:53,700 caused by the tsunami or the storm charge. 497 00:25:53,733 --> 00:25:59,200 From the back of this waterway, the storm charge comes this way. 498 00:25:59,233 --> 00:26:03,766 This structure here simulates the breakwaters. 499 00:26:03,800 --> 00:26:06,166 The waves go beyond the breakwater 500 00:26:06,200 --> 00:26:09,900 and reach the towns near Tokyo. 501 00:26:09,933 --> 00:26:12,866 We observe how the water behaves in this area 502 00:26:12,900 --> 00:26:15,400 using this hydraulic simulator. 503 00:26:15,433 --> 00:26:18,133 ♪♪ 504 00:26:18,166 --> 00:26:21,400 -Using the simulator to recreate a storm surge, 505 00:26:21,433 --> 00:26:23,533 Shibayama and his research assistants 506 00:26:23,566 --> 00:26:26,533 record it on a high-speed camera. 507 00:26:26,566 --> 00:26:31,266 A colored dye allows them to see the water's behavior in detail. 508 00:26:31,300 --> 00:26:34,033 -3, 2, 1, go. 509 00:26:36,700 --> 00:26:38,433 -Once the experiment is complete, 510 00:26:38,466 --> 00:26:42,200 Shibayama can look at the data collected by cameras and sensors 511 00:26:42,233 --> 00:26:45,533 to determine the water's motion after it hits the barrier. 512 00:26:48,233 --> 00:26:51,333 He concludes that the storm surge washed over the wall, 513 00:26:51,366 --> 00:26:53,033 putting weight on the top, 514 00:26:53,066 --> 00:26:55,000 and then dealt a vicious backwards blow 515 00:26:55,033 --> 00:26:58,466 to the support structures underneath. 516 00:26:58,500 --> 00:27:00,500 -It gets really fast here. 517 00:27:00,533 --> 00:27:02,066 We must check the velocity field 518 00:27:02,100 --> 00:27:03,433 and pressure field. 519 00:27:03,466 --> 00:27:04,933 [ Metal clacks ] 520 00:27:04,966 --> 00:27:07,166 -Once it gets past the breakwater, 521 00:27:07,200 --> 00:27:09,233 powerful vortices push and pull 522 00:27:09,266 --> 00:27:12,333 at the concrete in all directions 523 00:27:12,366 --> 00:27:17,633 with a force the wall's designers did not anticipate. 524 00:27:17,666 --> 00:27:19,333 Still, some experts believe 525 00:27:19,366 --> 00:27:22,066 that even Japan's most advanced engineering 526 00:27:22,100 --> 00:27:26,400 is no match for the increasing power of the sea. 527 00:27:26,433 --> 00:27:28,633 -The hard solutions that people talk about -- 528 00:27:28,666 --> 00:27:32,300 various gates, levies, walls, and so forth, 529 00:27:32,333 --> 00:27:33,600 I'm not sure it's practical 530 00:27:33,633 --> 00:27:35,466 because sometimes, it's just not clear to me 531 00:27:35,500 --> 00:27:37,000 that the science is there that says 532 00:27:37,033 --> 00:27:39,333 it's really gonna do the job it's meant to do. 533 00:27:39,366 --> 00:27:41,800 -Vishaan Chakrabarti is a New York architect 534 00:27:41,833 --> 00:27:44,466 specializing in storm resilience. 535 00:27:44,500 --> 00:27:46,166 -It's a basic Albert Einstein thing. 536 00:27:46,200 --> 00:27:47,733 Matter doesn't just disappear. 537 00:27:47,766 --> 00:27:51,000 The water just doesn't magically go away when you build a wall. 538 00:27:51,033 --> 00:27:54,166 It gets redirected to someone else's doorstep, 539 00:27:54,200 --> 00:27:56,800 and I think that's a fundamental issue that, 540 00:27:56,833 --> 00:27:59,133 again, I can't solve as an architect. 541 00:27:59,166 --> 00:28:03,166 I think most people who deal with this can't really solve. 542 00:28:03,200 --> 00:28:05,300 -No wall is fail-safe. 543 00:28:05,333 --> 00:28:07,933 So I think it does tend to encourage people 544 00:28:07,966 --> 00:28:11,866 to live behind the wall in a way that's not resourceful, 545 00:28:11,900 --> 00:28:15,833 in a way that trusts the wall to never fail. 546 00:28:15,866 --> 00:28:18,300 And, uh, that's not good. 547 00:28:18,333 --> 00:28:20,733 -Urban designer Kristina Hill warns against 548 00:28:20,766 --> 00:28:24,266 what in her specialty are called "hard solutions." 549 00:28:24,300 --> 00:28:26,233 The water always wins. 550 00:28:26,266 --> 00:28:28,266 -When you build a wall, you size the foundation 551 00:28:28,300 --> 00:28:30,066 for the height of the wall. 552 00:28:30,100 --> 00:28:32,266 If you -- you can't just add more bricks to the top 553 00:28:32,300 --> 00:28:34,866 and have it be structurally sound. 554 00:28:34,900 --> 00:28:36,666 So future generations, 555 00:28:36,700 --> 00:28:40,233 if that's not big enough, have to actually replace it. 556 00:28:40,266 --> 00:28:43,966 -Dr. Shibayama also knows no seawall is invincible. 557 00:28:44,000 --> 00:28:47,633 The revised plan is not to build higher or even stronger. 558 00:28:47,666 --> 00:28:50,033 Rather than try to deflect the storm surge, 559 00:28:50,066 --> 00:28:52,866 the new breakwater is designed to absorb its energy 560 00:28:52,900 --> 00:28:55,966 and in extreme cases allow water to flow over top 561 00:28:56,000 --> 00:28:57,966 without ripping it apart. 562 00:28:58,000 --> 00:29:00,533 -[ Speaking Japanese ] 563 00:29:00,566 --> 00:29:03,300 -The role of such hard structures as breakwaters 564 00:29:03,333 --> 00:29:08,033 and tsunami storm surge walls isn't a complete defense, 565 00:29:08,066 --> 00:29:11,566 rather, as with the case of Kamaishi, 566 00:29:11,600 --> 00:29:15,566 they delay the storm's impact by reducing its energy. 567 00:29:15,600 --> 00:29:19,633 -[ Speaking Japanese ] 568 00:29:19,666 --> 00:29:21,600 -What we need to change moving forward 569 00:29:21,633 --> 00:29:25,266 is that we are in the era in which each one of us 570 00:29:25,300 --> 00:29:28,066 must think about how we are going to survive 571 00:29:28,100 --> 00:29:30,933 and how we are going to protect our families 572 00:29:30,966 --> 00:29:34,500 even if water goes over hard structures. 573 00:29:34,533 --> 00:29:37,233 ♪♪ 574 00:29:37,266 --> 00:29:45,000 -Typhoons, tsunamis, earthquakes, 575 00:29:45,033 --> 00:29:50,200 rising seas, liquefaction, sinking neighborhoods. 576 00:29:50,233 --> 00:29:53,000 Tokyo, the world's most populous city, 577 00:29:53,033 --> 00:29:55,566 has the world's largest set of problems. 578 00:29:55,600 --> 00:29:58,400 -So when you pile up all of those elements together -- 579 00:29:58,433 --> 00:30:03,433 so the sea level will rise one meter, plus the quake, 580 00:30:03,466 --> 00:30:04,933 that's two meter. 581 00:30:04,966 --> 00:30:10,033 Plus, eventually, a typhoon that can bring the water level 582 00:30:10,066 --> 00:30:12,433 a meter higher, so that's three meters. 583 00:30:12,466 --> 00:30:14,833 And if you are unlucky at that time 584 00:30:14,866 --> 00:30:16,566 that you have flood from the rivers 585 00:30:16,600 --> 00:30:17,866 or you have a small tsunami 586 00:30:17,900 --> 00:30:21,300 that are predicted to be between 1 and 1.5 meter, 587 00:30:21,333 --> 00:30:23,900 all piling those elements together, 588 00:30:23,933 --> 00:30:25,833 well, you're in deep trouble. 589 00:30:25,866 --> 00:30:27,966 It's not a question of is it going to happen. 590 00:30:28,000 --> 00:30:31,366 It's a question of wh 591 00:30:28,000 --> 00:30:31,366 en 592 00:30:28,000 --> 00:30:31,366 it is going to happen. 593 00:30:31,400 --> 00:30:36,033 ♪♪ 594 00:30:36,066 --> 00:30:38,000 -Nonetheless, Tokyo may be one 595 00:30:38,033 --> 00:30:39,800 of the very few cities in the world 596 00:30:39,833 --> 00:30:43,433 seriously grappling with the challenge of climate change. 597 00:30:43,466 --> 00:30:46,333 It's figured out engineering solutions before, 598 00:30:46,366 --> 00:30:51,400 and with sea levels rising, Japan now needs to do it again. 599 00:30:51,433 --> 00:30:55,633 In 1993, before climate change was much discussed, 600 00:30:55,666 --> 00:30:58,766 Tokyo decided to tackle its existing flood problem 601 00:30:58,800 --> 00:31:01,033 with a megaproject that many believe 602 00:31:01,066 --> 00:31:03,733 was decades ahead of its time. 603 00:31:03,766 --> 00:31:08,633 ♪♪ 604 00:31:08,666 --> 00:31:13,500 ♪♪ 605 00:31:13,533 --> 00:31:17,333 Japan built a futuristic cavern to protect itself against water 606 00:31:17,366 --> 00:31:21,866 from above, below, or from the surrounding sea. 607 00:31:21,900 --> 00:31:25,633 -[ Speaking Japanese ] -We are in the surge tank. 608 00:31:25,666 --> 00:31:29,600 We have come down to 65 feet the ground. 609 00:31:29,633 --> 00:31:33,333 On the left hand side is Shaft #1. 610 00:31:33,366 --> 00:31:37,633 Further down the tunnel, we also have Shaft #2, 3, 611 00:31:37,666 --> 00:31:39,533 4, and 5. 612 00:31:39,566 --> 00:31:42,400 The overflow from flooding 613 00:31:42,433 --> 00:31:44,600 is collected through these shafts 614 00:31:44,633 --> 00:31:46,233 and goes through the tunnel 615 00:31:46,266 --> 00:31:50,466 to come up through Shaft #1 gradually. 616 00:31:50,500 --> 00:31:51,566 -[ Speaking Japanese ] 617 00:31:51,600 --> 00:31:53,066 -The water then flows 618 00:31:53,100 --> 00:31:55,600 into the Showa Drainage Pump Station 619 00:31:55,633 --> 00:31:57,700 through this surge tank. 620 00:31:57,733 --> 00:32:00,633 -[ Speaking Japanese ] 621 00:32:02,000 --> 00:32:06,566 -When water floods Tokyo, this is where it all goes. 622 00:32:06,600 --> 00:32:09,033 -[ Speaking Japanese ] 623 00:32:09,066 --> 00:32:12,866 -The accumulated water will rise, 624 00:32:12,900 --> 00:32:17,500 and eventually, it will reach a certain level. 625 00:32:17,533 --> 00:32:19,666 Then, it gets forced through the four pumps 626 00:32:19,700 --> 00:32:22,100 of the Showa Drainage Pump system 627 00:32:22,133 --> 00:32:24,733 to be drained out to the Edo River. 628 00:32:24,766 --> 00:32:27,866 -[ Speaking Japanese ] 629 00:32:31,300 --> 00:32:33,633 -We have the water flowing into our facility 630 00:32:33,666 --> 00:32:36,933 about seven times a year on average. 631 00:32:36,966 --> 00:32:38,766 Out of those 7 times, 632 00:32:38,800 --> 00:32:41,066 for about 60 percent of the time, 633 00:32:41,100 --> 00:32:42,700 the water flows into here 634 00:32:42,733 --> 00:32:45,333 and is forced out to the Edo River. 635 00:32:45,366 --> 00:32:47,866 For the remaining 40 percent of the time, 636 00:32:47,900 --> 00:32:49,300 we store the water here 637 00:32:49,333 --> 00:32:53,066 as it can hold up to 670,000 tons, 638 00:32:53,100 --> 00:32:57,233 and then the water gets returned to the river it came from. 639 00:32:57,266 --> 00:33:01,166 -The system can hold up to 65 million gallons of water 640 00:33:01,200 --> 00:33:04,566 and can pump it out as quickly as it comes in. 641 00:33:04,600 --> 00:33:07,100 Lewis Makana is a UK-based engineer 642 00:33:07,133 --> 00:33:10,366 focused on the problem of storm water management. 643 00:33:10,400 --> 00:33:12,200 -For the mind's eye to capture the scale 644 00:33:12,233 --> 00:33:14,033 and size of these silos, 645 00:33:14,066 --> 00:33:15,900 you can take the Statue of Liberty 646 00:33:15,933 --> 00:33:17,466 and place it inside one of those silos. 647 00:33:17,500 --> 00:33:19,666 That's how big it is. 648 00:33:19,700 --> 00:33:21,333 It's quite impressive. 649 00:33:21,366 --> 00:33:23,500 Flooding in Tokyo is a big challenge. 650 00:33:23,533 --> 00:33:25,900 If they didn't have that type of protection, 651 00:33:25,933 --> 00:33:28,233 they would be gone. 652 00:33:28,266 --> 00:33:30,700 ♪♪ 653 00:33:30,733 --> 00:33:34,100 -[ Speaking Japanese ] 654 00:33:34,133 --> 00:33:37,966 -It took 13 years to construct this facility -- 655 00:33:38,000 --> 00:33:43,400 from 1993 to 2006. 656 00:33:43,433 --> 00:33:48,733 In actual figures, it cost 230 billion yen. 657 00:33:48,766 --> 00:33:53,133 -That's more than $2 billion. 658 00:33:53,166 --> 00:33:56,400 -Some domestic and international evaluations 659 00:33:56,433 --> 00:33:58,900 consider this to be expensive. 660 00:33:58,933 --> 00:34:02,300 However, the flood damages in this region 661 00:34:02,333 --> 00:34:06,633 have been reduced to approximately one-tenth. 662 00:34:06,666 --> 00:34:09,500 Therefore, I think it is not that expensive 663 00:34:09,533 --> 00:34:13,400 when you take the flood damages into consideration. 664 00:34:13,433 --> 00:34:17,133 -In 2015, after a record rainfall, 665 00:34:17,166 --> 00:34:20,566 this temple to engineering was filled to the brim. 666 00:34:20,600 --> 00:34:23,066 But the heaviest of those rains missed Tokyo, 667 00:34:23,100 --> 00:34:27,000 with the greater impact outside the city to the northeast. 668 00:34:27,033 --> 00:34:29,933 Kuniharu says the giant Showa Drainage Pump system 669 00:34:29,966 --> 00:34:33,533 could not have coped if that storm had directly hit Tokyo. 670 00:34:33,566 --> 00:34:35,766 -[ Speaking Japanese ] 671 00:34:35,800 --> 00:34:39,366 -I heard it was the greatest amount of inflow and drainage 672 00:34:39,400 --> 00:34:42,733 since this facility began its operation. 673 00:34:44,466 --> 00:34:47,033 Our facility has four pumps, 674 00:34:47,066 --> 00:34:50,000 and we usually use one or two at a time. 675 00:34:50,033 --> 00:34:54,066 2015 was the first time all four pumps operated 676 00:34:54,100 --> 00:34:58,133 at full capacity simultaneously for more than a week 677 00:34:58,166 --> 00:35:00,866 to drain the water in an effort to mitigate 678 00:35:00,900 --> 00:35:03,400 flooding in the region. 679 00:35:03,433 --> 00:35:06,400 -Once the tank is full, it drains into the Edo River 680 00:35:06,433 --> 00:35:08,766 at a rate of 53,000 gallons, 681 00:35:08,800 --> 00:35:11,366 the capacity of an Olympic size swimming pool, 682 00:35:11,400 --> 00:35:13,566 every 12 seconds. 683 00:35:13,600 --> 00:35:17,700 It's the most advanced flood mitigation system on the planet. 684 00:35:17,733 --> 00:35:20,333 But recent record rainfalls are too much 685 00:35:20,366 --> 00:35:24,333 for even the massive reservoirs to handle. 686 00:35:24,366 --> 00:35:25,466 -[ Speaking Japanese ] 687 00:35:25,500 --> 00:35:27,200 -We do get questioned about what happens 688 00:35:27,233 --> 00:35:30,466 if we had a rainfall of a similar scale, 689 00:35:30,500 --> 00:35:33,533 and we must admit that we are not fully certain. 690 00:35:36,666 --> 00:35:39,700 To build a facility in the first place, 691 00:35:39,733 --> 00:35:43,033 there is an expected amount of water that will flow into it. 692 00:35:47,200 --> 00:35:51,233 This facility was designed to cope with that amount. 693 00:35:51,266 --> 00:35:53,366 But if there is a rainfall or water flow 694 00:35:53,400 --> 00:35:56,766 that is above this upper limit, 695 00:35:56,800 --> 00:36:01,600 we will not be able to take it in nor drain it out. 696 00:36:01,633 --> 00:36:04,300 It is unavoidable that the local communities 697 00:36:04,333 --> 00:36:06,800 will pay the price in such a case. 698 00:36:10,066 --> 00:36:12,766 -With increased rainfall and rising seas, 699 00:36:12,800 --> 00:36:14,666 engineers like Dr. Makana believe 700 00:36:14,700 --> 00:36:19,966 the facility is no longer 100 percent effective. 701 00:36:20,000 --> 00:36:23,200 -Even with this amazing superstructure, 702 00:36:23,233 --> 00:36:27,533 they still recognize that because of climate change, 703 00:36:27,566 --> 00:36:30,433 because of the rising sea level, and because of the potential, 704 00:36:30,466 --> 00:36:32,000 using scenario modeling 705 00:36:32,033 --> 00:36:33,433 and looking at the worst-case scenario 706 00:36:33,466 --> 00:36:36,266 of what potentially could be the worst-case type of tide, 707 00:36:36,300 --> 00:36:40,000 tidal surge, in addition to maybe a typhoon event, 708 00:36:40,033 --> 00:36:44,333 they recognize this protection that is currently in place 709 00:36:44,366 --> 00:36:46,633 will not be fit for purpose. 710 00:36:46,666 --> 00:36:48,966 That will be something for them to discuss and feature 711 00:36:49,000 --> 00:36:50,900 in their future planning for Tokyo, 712 00:36:50,933 --> 00:36:54,266 but it will need to be put in place, 713 00:36:54,300 --> 00:36:57,466 or else Tokyo will be submerged by flooding. 714 00:36:59,300 --> 00:37:01,366 [ Water sloshes ] 715 00:37:10,366 --> 00:37:17,233 ♪♪ 716 00:37:17,266 --> 00:37:20,566 -Tokyo is protected by a series of 44 flood gates 717 00:37:20,600 --> 00:37:23,033 along the city's many rivers. 718 00:37:23,066 --> 00:37:27,633 They are designed to stop storm surges as high as 26 feet. 719 00:37:27,666 --> 00:37:31,000 The highest ever recorded in Tokyo is only 10 feet. 720 00:37:31,033 --> 00:37:34,133 ♪♪ 721 00:37:34,166 --> 00:37:36,066 -[ Speaking Japanese ] 722 00:37:36,100 --> 00:37:38,833 -In the event of tsunamis or storm surges, 723 00:37:38,866 --> 00:37:40,466 we are supposed to close the gate 724 00:37:40,500 --> 00:37:44,566 when the water reaches a certain level. 725 00:37:44,600 --> 00:37:45,966 -Even with sea level rise, 726 00:37:46,000 --> 00:37:48,333 the floodgates offer substantial protection 727 00:37:48,366 --> 00:37:50,133 to over a quarter of Tokyo. 728 00:37:50,166 --> 00:37:53,500 -[ Speaking Japanese ] 729 00:37:53,533 --> 00:37:57,033 -You see that there are seawalls all around the gate, 730 00:37:57,066 --> 00:37:58,900 and the walls look high. 731 00:37:58,933 --> 00:38:02,566 But inside the walls, it's actually fairly low. 732 00:38:02,600 --> 00:38:04,433 So if we don't close the gate, 733 00:38:04,466 --> 00:38:08,300 the area inside the walls would be submerged. 734 00:38:11,200 --> 00:38:13,300 -If the water overflows the riverbanks, 735 00:38:13,333 --> 00:38:16,600 pumping stations are activated. 736 00:38:16,633 --> 00:38:21,333 -[ Speaking Japanese ] 737 00:38:21,366 --> 00:38:23,533 -When the water level on the inner side 738 00:38:23,566 --> 00:38:27,900 of a closed water gate rises with rain, 739 00:38:27,933 --> 00:38:30,466 you use this pump to move the water 740 00:38:30,500 --> 00:38:34,566 accumulated inside the gate to the other side of the gate. 741 00:38:34,600 --> 00:38:38,033 -[ Speaking Japanese 742 00:38:38,066 --> 00:38:40,166 ♪♪ 743 00:38:40,200 --> 00:38:41,633 -The next line of defense 744 00:38:41,666 --> 00:38:43,466 is what's called super levees, 745 00:38:43,500 --> 00:38:47,166 which are currently being built all around Tokyo. 746 00:38:47,200 --> 00:38:49,900 Dr. Kristina Hill believes the levees are Japan's 747 00:38:49,933 --> 00:38:53,833 best long-term solution against the rising sea. 748 00:38:53,866 --> 00:38:55,500 -What they did was they piled up 749 00:38:55,533 --> 00:38:57,366 all this earthquake-safe material, 750 00:38:57,400 --> 00:39:00,666 so that means carefully sorted gravels and sands, 751 00:39:00,700 --> 00:39:04,066 um, and then they extended everybody's property lines 752 00:39:04,100 --> 00:39:07,266 up into the air through that new material, 753 00:39:07,300 --> 00:39:09,400 and gave the original property owners 754 00:39:09,433 --> 00:39:12,400 rights to redevelop buildings on top 755 00:39:12,433 --> 00:39:15,033 that now have water views in some cases. 756 00:39:15,066 --> 00:39:17,900 So I think it's a fantastic idea. 757 00:39:17,933 --> 00:39:22,433 Even if the dike is overtopped, if water comes over the top, 758 00:39:22,466 --> 00:39:24,966 they've built terraces on the backside 759 00:39:25,000 --> 00:39:26,833 that should slow that water down 760 00:39:26,866 --> 00:39:31,366 as it moved towards highly populated areas in Tokyo. 761 00:39:31,400 --> 00:39:34,833 So important to slow flooding down. 762 00:39:34,866 --> 00:39:37,366 -Nobuyuki Tsuchiya is lead engineer 763 00:39:37,400 --> 00:39:39,400 on the super levee project. 764 00:39:39,433 --> 00:39:42,533 -[ Speaking Japanese ] 765 00:39:42,566 --> 00:39:44,266 -With the ground subsidence, 766 00:39:44,300 --> 00:39:47,600 we had to reinforce the levees by adding height. 767 00:39:47,633 --> 00:39:50,400 That's why this one looks a bit steep. 768 00:39:50,433 --> 00:39:53,433 When it was originally made, it was more gradual. 769 00:39:53,466 --> 00:39:57,300 Because we added the height, it's a bit unbalanced. 770 00:39:57,333 --> 00:39:59,933 -[ Speaking Japanese ] 771 00:39:59,966 --> 00:40:02,300 Because it's such a serious problem, 772 00:40:02,333 --> 00:40:05,166 we've been working on this super levee project, 773 00:40:05,200 --> 00:40:06,900 which would make this residential ground 774 00:40:06,933 --> 00:40:08,866 as high as the levees 775 00:40:08,900 --> 00:40:11,300 and defend the community from water. 776 00:40:11,333 --> 00:40:15,900 -[ Speaking Japanese ] 777 00:40:15,933 --> 00:40:17,833 -The super levees were planned to run 778 00:40:17,866 --> 00:40:22,800 for 540 miles along 6 rivers to a height of 30 feet. 779 00:40:22,833 --> 00:40:26,100 But that plan was so expensive, it was scaled down to protect 780 00:40:26,133 --> 00:40:29,166 only the most vulnerable, low-lying areas. 781 00:40:29,200 --> 00:40:32,500 Still, it comes at a cost to Tokyo's landscape 782 00:40:32,533 --> 00:40:34,833 and for residents who have to leave their homes 783 00:40:34,866 --> 00:40:38,100 as their entire neighborhoods are elevated. 784 00:40:38,133 --> 00:40:41,766 -And then we fill the land and raise the ground level. 785 00:40:41,800 --> 00:40:43,466 Then we build roads, parks, 786 00:40:43,500 --> 00:40:46,200 and rebuild the town from scratch. 787 00:40:46,233 --> 00:40:48,633 Then the residents can come back. 788 00:40:48,666 --> 00:40:51,300 ♪♪ 789 00:40:51,333 --> 00:40:53,333 -The people of Tokyo have come to realize 790 00:40:53,366 --> 00:40:55,400 that they have few good options. 791 00:40:55,433 --> 00:40:58,500 It's either evacuate for a short time for rebuilding 792 00:40:58,533 --> 00:41:02,133 or abandon their homes for good. 793 00:41:02,166 --> 00:41:05,333 -It's going to be challenging, but if this levee breaks, 794 00:41:05,366 --> 00:41:08,300 it's not only these houses that get destroyed, 795 00:41:08,333 --> 00:41:12,166 but also the water would overrun the whole Tokyo area. 796 00:41:14,466 --> 00:41:19,233 If you think about that, then asking for some cooperation 797 00:41:19,266 --> 00:41:21,233 and time from the residents here 798 00:41:21,266 --> 00:41:24,266 would make the most sense for the safety of Tokyo. 799 00:41:24,300 --> 00:41:27,300 -[ Speaking Japanese ] 800 00:41:30,933 --> 00:41:33,800 ♪♪ 801 00:41:33,833 --> 00:41:35,800 [ Siren wails ] 802 00:41:35,833 --> 00:41:40,866 ♪♪ 803 00:41:40,900 --> 00:41:42,466 [ Birds crying ] 804 00:41:42,500 --> 00:41:45,100 -Tokyo has to seek a whole array of solutions 805 00:41:45,133 --> 00:41:47,066 and keep re-engineering itself 806 00:41:47,100 --> 00:41:50,000 for a future of rising seas. 807 00:41:50,033 --> 00:41:52,500 -So the coastal defenses in Tokyo 808 00:41:52,533 --> 00:41:55,966 are some of best in the world 809 00:41:56,000 --> 00:41:57,366 by a long range. 810 00:41:57,400 --> 00:41:59,800 And Tokyo City has been rising up their differences 811 00:41:59,833 --> 00:42:02,033 to meet those challenges. 812 00:42:02,066 --> 00:42:04,500 Does it mean that it's going to be enough 813 00:42:04,533 --> 00:42:06,200 for the future challenges? 814 00:42:06,233 --> 00:42:09,800 That's another question. 815 00:42:09,833 --> 00:42:14,066 -The city may have to consider ideas from outside of Japan. 816 00:42:14,100 --> 00:42:17,433 Kunlé Adeyemi is an architect whose focus is on building 817 00:42:17,466 --> 00:42:20,333 near, and even on, water. 818 00:42:20,366 --> 00:42:22,100 Faced with climate change, he believes 819 00:42:22,133 --> 00:42:25,700 humanity has to adapt its thinking before it's too late. 820 00:42:25,733 --> 00:42:29,233 -I am a realistic optimist. 821 00:42:29,266 --> 00:42:31,466 [ Laughs ] 822 00:42:31,500 --> 00:42:33,466 And what I mean by that 823 00:42:33,500 --> 00:42:36,866 is that I'm realistic in the sense that, 824 00:42:36,900 --> 00:42:38,300 you know, I go to Tokyo, 825 00:42:38,333 --> 00:42:43,966 and I see the impact of sea level rise, 826 00:42:44,000 --> 00:42:47,466 climate change, or simply water. 827 00:42:47,500 --> 00:42:50,800 I just see places that used to be land 828 00:42:50,833 --> 00:42:52,900 are now covered by water. 829 00:42:52,933 --> 00:42:54,600 That is the real fact. 830 00:42:54,633 --> 00:42:56,133 I don't want to see that as a problem. 831 00:42:56,166 --> 00:42:58,500 I want to see that as an opportunity. 832 00:42:58,533 --> 00:43:00,733 And how do I deal with this opportunity 833 00:43:00,766 --> 00:43:05,300 where I have to learn to live with water 834 00:43:05,333 --> 00:43:07,300 as opposed to fighting it? 835 00:43:07,333 --> 00:43:08,966 And that's what I see -- 836 00:43:09,000 --> 00:43:14,633 we're producing infrastructure for water culture. 837 00:43:14,666 --> 00:43:17,533 -Adeyemi has proposed an experimental design 838 00:43:17,566 --> 00:43:20,433 for temporary, low-cost floating habitats 839 00:43:20,466 --> 00:43:24,100 that can be used for housing, office space, or schools. 840 00:43:24,133 --> 00:43:27,033 -Well, so, the idea is that we're trying to create 841 00:43:27,066 --> 00:43:29,200 a building system 842 00:43:29,233 --> 00:43:33,733 where the components are easy to fabricate 843 00:43:33,766 --> 00:43:35,933 in any kind of local region 844 00:43:35,966 --> 00:43:37,466 and assemble. 845 00:43:37,500 --> 00:43:38,900 No matter where you are in the world, 846 00:43:38,933 --> 00:43:42,700 you can find a particular class of timber 847 00:43:42,733 --> 00:43:47,000 that will be suitable for the production of the structure. 848 00:43:47,033 --> 00:43:50,533 -Adeyemi's design has been considered for several cities, 849 00:43:50,566 --> 00:43:52,733 including Tokyo. 850 00:43:52,766 --> 00:43:56,733 It can easily be adapted to Tokyo's unique environment. 851 00:43:56,766 --> 00:43:59,000 Temperatures rarely drop below freezing, 852 00:43:59,033 --> 00:44:00,433 and the structure can be made 853 00:44:00,466 --> 00:44:03,000 to ride out heavy rains and waves. 854 00:44:03,033 --> 00:44:04,866 -We've used two systems so far, 855 00:44:04,900 --> 00:44:08,666 the first being just very basic, recycled plastic barrels 856 00:44:08,700 --> 00:44:11,766 that are used in industrial areas 857 00:44:11,800 --> 00:44:15,733 and second, has been uh, the expanded polystyrene, 858 00:44:15,766 --> 00:44:18,500 which is used in construction. 859 00:44:18,533 --> 00:44:20,300 We know there are different technologies 860 00:44:20,333 --> 00:44:23,133 for creating floatation devices 861 00:44:23,166 --> 00:44:27,500 that would enable this to work in different parts of the world. 862 00:44:27,533 --> 00:44:30,933 ♪♪ 863 00:44:30,966 --> 00:44:35,633 -Engineer Toshio Nakajima has an even more ambitious idea. 864 00:44:35,666 --> 00:44:39,666 He's proposed an entire floating city in Tokyo Bay. 865 00:44:39,700 --> 00:44:41,300 -[ Speaking Japanese ] 866 00:44:41,333 --> 00:44:43,366 -The concept of this floating city 867 00:44:43,400 --> 00:44:46,633 is to make the lowest land as safe as possible. 868 00:44:46,666 --> 00:44:50,233 So we dig it out to make the low land even lower, 869 00:44:50,266 --> 00:44:53,000 and then we flood it. 870 00:44:53,033 --> 00:44:54,933 After putting the water in, 871 00:44:54,966 --> 00:44:58,666 we build the floating foundation, 872 00:44:58,700 --> 00:45:01,533 and we live on it so that when it rains 873 00:45:01,566 --> 00:45:03,600 and the water level goes up, 874 00:45:03,633 --> 00:45:06,300 the city itself is raised with the water 875 00:45:06,333 --> 00:45:09,100 and protects itself from water disasters. 876 00:45:11,500 --> 00:45:15,000 -Nakajima based his design on the Mega-Float -- 877 00:45:15,033 --> 00:45:17,533 a floating airplane runway in Tokyo Bay -- 878 00:45:17,566 --> 00:45:20,633 that has proven to be very effective. 879 00:45:20,666 --> 00:45:23,466 Nakajima's city would use the same technology, 880 00:45:23,500 --> 00:45:26,400 basically a gigantic modular floating dock. 881 00:45:26,433 --> 00:45:29,333 -[ Speaking Japanese ] 882 00:45:29,366 --> 00:45:33,666 -This water is taken from the Arakawa River, 883 00:45:33,700 --> 00:45:35,600 and the water goes through the city 884 00:45:35,633 --> 00:45:38,666 and goes out into the sea. 885 00:45:38,700 --> 00:45:43,233 So the city controls the water. 886 00:45:43,266 --> 00:45:47,200 -[ Speaking Japanese ] 887 00:45:47,233 --> 00:45:50,866 -The energy we need to move the water through the city 888 00:45:50,900 --> 00:45:55,200 is generated in this area here by using the solar panels. 889 00:45:55,233 --> 00:46:00,600 -[ Speaking Japanese ] 890 00:46:00,633 --> 00:46:02,866 -We would have a big tank underwater, 891 00:46:02,900 --> 00:46:08,466 located below the city, to store rainwater, too. 892 00:46:08,500 --> 00:46:12,833 -[ Speaking Japanese ] 893 00:46:12,866 --> 00:46:17,100 -We won't need anything difficult technology-wise. 894 00:46:17,133 --> 00:46:22,200 If we're serious about it, we can build it anytime. 895 00:46:22,233 --> 00:46:24,100 -Nakajima's floating city would look 896 00:46:24,133 --> 00:46:26,733 something like this video simulation. 897 00:46:26,766 --> 00:46:30,200 It would be able to withstand sea level rise, storm surges, 898 00:46:30,233 --> 00:46:32,000 and extreme rainfall. 899 00:46:32,033 --> 00:46:33,933 But Tokyo's cash-strapped government 900 00:46:33,966 --> 00:46:36,566 has not approved the plan so far. 901 00:46:36,600 --> 00:46:41,100 -I think it's not only Tokyo, but in all of Japan, 902 00:46:41,133 --> 00:46:44,266 people want to keep their conventional ways. 903 00:46:44,300 --> 00:46:47,233 -[ Speaking Japanese ] 904 00:46:47,266 --> 00:46:50,600 -I have the impression that many people are conservative 905 00:46:50,633 --> 00:46:54,100 and not open to new ideas. 906 00:46:54,133 --> 00:46:57,500 -Tokyo has to survive the rising waters. 907 00:46:57,533 --> 00:47:00,033 The future of Japan depends on it. 908 00:47:00,066 --> 00:47:02,300 Yet that may mean reshaping the city 909 00:47:02,333 --> 00:47:05,900 by retreating from the areas in the greatest danger. 910 00:47:05,933 --> 00:47:10,300 -One of the cheapest solution and one of the easiest solution, 911 00:47:10,333 --> 00:47:13,100 at least on paper, might be the retreat 912 00:47:13,133 --> 00:47:15,733 from the most floodable areas of Tokyo. 913 00:47:15,766 --> 00:47:18,066 [ Thunder rumbles ] 914 00:47:18,100 --> 00:47:19,466 -By the end of the century, 915 00:47:19,500 --> 00:47:21,700 Tokyo's world-famous Shibuya district 916 00:47:21,733 --> 00:47:25,033 could be one place to be abandoned to the waters. 917 00:47:25,066 --> 00:47:27,366 -We're going to see the population shrinking, 918 00:47:27,400 --> 00:47:29,133 so less people in the city. 919 00:47:29,166 --> 00:47:30,666 And that's maybe a chance 920 00:47:30,700 --> 00:47:32,733 to remodel the city in which we live. 921 00:47:32,766 --> 00:47:35,433 How can we concentrate people in safe areas 922 00:47:35,466 --> 00:47:38,200 and abandon slowly and naturally 923 00:47:38,233 --> 00:47:41,333 areas that are too dangerous to live in? 924 00:47:41,366 --> 00:47:43,733 -I think the question's not just about 925 00:47:43,766 --> 00:47:48,900 whether we retreat or we stand our ground 926 00:47:48,933 --> 00:47:50,866 because that sets this opposition 927 00:47:50,900 --> 00:47:55,033 between humanity and the environment. 928 00:47:55,066 --> 00:47:58,066 It's a reconsideration 929 00:47:58,100 --> 00:48:01,700 of how to ensure that there's coexistence. 930 00:48:01,733 --> 00:48:03,966 So there needs to be a balance, 931 00:48:04,000 --> 00:48:06,566 and I think where we've always created walls 932 00:48:06,600 --> 00:48:09,000 between us and the environment, 933 00:48:09,033 --> 00:48:10,800 now we need to let go of the walls 934 00:48:10,833 --> 00:48:15,466 and find new ways of bridging the gap. 935 00:48:17,466 --> 00:48:20,966 -Some believe solutions may be rediscovered from history. 936 00:48:21,000 --> 00:48:22,933 "Resiliency" is now a buzzword 937 00:48:22,966 --> 00:48:25,733 of climate change engineering and design. 938 00:48:25,766 --> 00:48:28,266 But it perfectly describes what the people of Tokyo 939 00:48:28,300 --> 00:48:30,333 have been doing for centuries. 940 00:48:30,366 --> 00:48:31,666 -[ Speaking Japanese ] 941 00:48:31,700 --> 00:48:36,100 -Our ancestors made the city here on a low, flat land, 942 00:48:36,133 --> 00:48:39,400 good for agriculture, and developed the city. 943 00:48:39,433 --> 00:48:42,400 -[ Speaking Japanese ] 944 00:48:42,433 --> 00:48:46,833 ♪♪ 945 00:48:46,866 --> 00:48:48,300 -People learned to live with the water 946 00:48:48,333 --> 00:48:51,366 when there was flooding. 947 00:48:51,400 --> 00:48:53,866 It's like a city in the water. 948 00:48:53,900 --> 00:48:55,266 In order to live there, 949 00:48:55,300 --> 00:48:57,433 people made their residence higher. 950 00:48:57,466 --> 00:49:01,466 We call it constructing a "Mizuya" or "Mizuka," 951 00:49:01,500 --> 00:49:03,566 a shelter from the flood. 952 00:49:03,600 --> 00:49:06,533 But when you go to work, you go on a boat. 953 00:49:06,566 --> 00:49:08,400 -[ Speaking Japanese ] 954 00:49:08,433 --> 00:49:11,333 -When the water recedes, you just hang your boat 955 00:49:11,366 --> 00:49:13,366 under the floor of your house. 956 00:49:13,400 --> 00:49:16,433 So people lived flexibly with the water. 957 00:49:16,466 --> 00:49:18,366 It was not about fighting the risk, 958 00:49:18,400 --> 00:49:23,766 but predicting it, accepting it, and living with it. 959 00:49:23,800 --> 00:49:26,700 -Tokyo is facing a huge amount of challenges, 960 00:49:26,733 --> 00:49:30,966 but people are still here, rising to those challenges. 961 00:49:31,000 --> 00:49:34,533 And the way they look at it, human beings are part of nature, 962 00:49:34,566 --> 00:49:36,000 part of the environment. 963 00:49:36,033 --> 00:49:37,866 Those hazards and disasters 964 00:49:37,900 --> 00:49:40,466 also part of the environment we live in, 965 00:49:40,500 --> 00:49:42,433 and we have to be able to live with it. 966 00:49:42,466 --> 00:49:43,633 -Those who lived through 967 00:49:43,666 --> 00:49:46,000 the most recent disasters to strike Tokyo 968 00:49:46,033 --> 00:49:48,366 are still adapting to their changing world, 969 00:49:48,400 --> 00:49:50,366 but they know they face challenges 970 00:49:50,400 --> 00:49:52,600 previous generations never did. 971 00:49:52,633 --> 00:49:54,166 -[ Speaking Japanese ] 972 00:49:54,200 --> 00:49:57,500 -It's over there. 973 00:49:57,533 --> 00:50:01,633 This is the manhole that popped out of the ground. 974 00:50:01,666 --> 00:50:05,300 It's left as a monument. 975 00:50:05,333 --> 00:50:07,200 This is it. 976 00:50:07,233 --> 00:50:11,366 ♪♪ 977 00:50:11,400 --> 00:50:14,066 It got pushed up out of the ground. 978 00:50:14,100 --> 00:50:18,633 It reminds me that this happened, 979 00:50:18,666 --> 00:50:19,966 and it makes me think 980 00:50:20,000 --> 00:50:23,266 that we don't want something like this again. 981 00:50:24,466 --> 00:50:27,633 My view now is that this is a place to pray 982 00:50:27,666 --> 00:50:30,333 for no more disasters. 983 00:50:34,633 --> 00:50:39,000 -Despite his prayers, sea levels continue to rise, 984 00:50:39,033 --> 00:50:42,966 typhoons grow stronger, and it rains more than ever. 985 00:50:43,000 --> 00:50:44,766 -[ Speaking Japanese ] -Yes. 986 00:50:44,800 --> 00:50:48,033 I'm worried so much that I can't sleep. 987 00:50:48,066 --> 00:50:52,500 That's why at this moment, too, we're trying to defend the city 988 00:50:52,533 --> 00:50:55,133 as much as possible against the water. 989 00:50:55,166 --> 00:50:58,066 -[ Speaking Japanese ] 990 00:50:58,100 --> 00:51:02,233 -We're building super levees, strengthening seawalls, 991 00:51:02,266 --> 00:51:05,933 improving pumping stations, and so on. 992 00:51:05,966 --> 00:51:08,566 -Human beings need to see danger. 993 00:51:08,600 --> 00:51:10,666 They need to know the world they live in 994 00:51:10,700 --> 00:51:13,333 in order to become more resourceful over time. 995 00:51:13,366 --> 00:51:15,900 We have a long haul here with climate change. 996 00:51:15,933 --> 00:51:18,066 It's not going to be over in 50 years. 997 00:51:18,100 --> 00:51:20,500 We need multiple generations 998 00:51:20,533 --> 00:51:23,133 to become courageous and resourceful 999 00:51:23,166 --> 00:51:26,000 and smart with their money and technology 1000 00:51:26,033 --> 00:51:28,466 and care about each other. 1001 00:51:28,500 --> 00:51:31,900 -With today's level of funding, today's engineering, 1002 00:51:31,933 --> 00:51:33,333 there is no clear answer 1003 00:51:33,366 --> 00:51:36,733 on how to engineer our way out of this problem. 1004 00:51:36,766 --> 00:51:38,866 But we're thinking about 50 years', 1005 00:51:38,900 --> 00:51:40,866 100 years' time from now. 1006 00:51:40,900 --> 00:51:43,500 And the engineering systems are going to progress, as well. 1007 00:51:43,533 --> 00:51:45,233 Nobody can tell what kind of solution 1008 00:51:45,266 --> 00:51:48,433 we're going to be able to create or build in 100 years. 1009 00:51:48,466 --> 00:51:50,833 -I would definitely say it is the Godzilla of all problems, 1010 00:51:50,866 --> 00:51:53,866 and I believe a lot of the problems we are facing 1011 00:51:53,900 --> 00:51:57,533 from climate change will require engineering-led solutions, 1012 00:51:57,566 --> 00:51:59,700 and whether an engineer can take on Godzilla 1013 00:51:59,733 --> 00:52:01,433 is what we are trying to find out. 1014 00:52:01,466 --> 00:52:02,633 [ Laughs ] 1015 00:52:02,666 --> 00:52:04,900 -It scares the bejesus out of me. 1016 00:52:04,933 --> 00:52:07,300 Living near the water, I think, 1017 00:52:07,333 --> 00:52:11,100 is something that is so core to the human spirit. 1018 00:52:11,133 --> 00:52:13,000 And even people who don't live near the oceans, 1019 00:52:13,033 --> 00:52:14,566 they go to lakes, they go to rivers. 1020 00:52:14,600 --> 00:52:15,700 I think this is just -- 1021 00:52:15,733 --> 00:52:18,200 we come from water as a species. 1022 00:52:18,233 --> 00:52:21,600 And so I just... To me, it's just so tragic, 1023 00:52:21,633 --> 00:52:24,900 the idea that we now have to think of water as the enemy. 1024 00:52:24,933 --> 00:52:27,333 What we have right now is we have a tool kit 1025 00:52:27,366 --> 00:52:30,533 that can help us make things better in the short term. 1026 00:52:30,566 --> 00:52:32,800 That's only going to buy us some time 1027 00:52:32,833 --> 00:52:35,200 as we figure out this problem on a global level, 1028 00:52:35,233 --> 00:52:38,233 but it's at the global level that it has to be figured out. 1029 00:52:40,700 --> 00:52:44,400 -Engineers, planners, and civic leaders in Tokyo 1030 00:52:44,433 --> 00:52:46,166 are addressing their epic challenge 1031 00:52:46,200 --> 00:52:50,066 with technology, engineering, and imagination -- 1032 00:52:50,100 --> 00:52:54,966 seeking solutions to protect the city for decades to come. 1033 00:52:55,000 --> 00:52:58,800 -[ Speaking Japanese ] 1034 00:52:58,833 --> 00:53:01,366 -Tokyo is trying to keep the water away 1035 00:53:01,400 --> 00:53:04,500 because it's being conventional. 1036 00:53:04,533 --> 00:53:07,866 They're trying to fight against the water. 1037 00:53:07,900 --> 00:53:09,666 But we can't keep doing that 1038 00:53:09,700 --> 00:53:13,133 because the water is something more powerful than us. 1039 00:53:13,166 --> 00:53:15,766 There's no way we would win. 1040 00:53:15,800 --> 00:53:21,366 -The more we learn to evolve and adapt 1041 00:53:21,400 --> 00:53:24,866 to what seems to be, 1042 00:53:24,900 --> 00:53:28,466 at least in the next 50, 100 years, the path, 1043 00:53:28,500 --> 00:53:32,866 the better we are in creating more livable environments. 1044 00:53:32,900 --> 00:53:36,400 And I think the human species 1045 00:53:36,433 --> 00:53:38,700 is an incredibly intelligent species, 1046 00:53:38,733 --> 00:53:43,933 and Tokyo will learn to live with water. 1047 00:53:43,966 --> 00:53:46,400 -[ Speaking Japanese ] 1048 00:53:46,433 --> 00:53:49,066 -Even though we have been trying our best, 1049 00:53:49,100 --> 00:53:50,433 I don't think we can say 1050 00:53:50,466 --> 00:53:53,766 that we are fully prepared for disasters. 1051 00:53:53,800 --> 00:53:59,533 ♪♪ 1052 00:54:01,800 --> 00:54:03,866 -Next time on "Sinking Cities," 1053 00:54:03,900 --> 00:54:06,433 London has been plagued by flooding for centuries. 1054 00:54:06,466 --> 00:54:08,366 -London probably has one of the longest 1055 00:54:08,400 --> 00:54:10,500 flood histories of anywhere in the world. 1056 00:54:10,533 --> 00:54:12,500 -They built the Thames Barrier 1057 00:54:12,533 --> 00:54:15,200 and believed flooding was a thing of the past. 1058 00:54:15,233 --> 00:54:17,433 Now a city that thought it was safe 1059 00:54:17,466 --> 00:54:19,833 is facing a new reality -- 1060 00:54:19,866 --> 00:54:22,366 sea levels are going up. 1061 00:54:22,400 --> 00:54:24,833 -A thousand properties got flooded 1062 00:54:24,866 --> 00:54:27,466 not from the tides, but the sky. 1063 00:54:27,500 --> 00:54:29,333 -You could get such a severe weather event, 1064 00:54:29,366 --> 00:54:30,366 it could overwhelm our defenses. 1065 00:54:32,300 --> 00:54:33,666 [ Indistinct conversations ] 1066 00:54:33,700 --> 00:54:39,433 ♪♪ 1067 00:54:39,466 --> 00:54:41,600 -To order "Sinking Cities" on DVD, 1068 00:54:41,633 --> 00:54:46,766 visit ShopPBS or call 1-800-PLAY-PBS. 1069 00:54:46,800 --> 00:54:50,266 This program is also available on Amazon Prime Video. 1070 00:54:50,300 --> 00:54:55,300 ♪♪ 1071 00:54:55,333 --> 00:55:00,433 ♪♪