1 00:00:00,437 --> 00:00:02,217 (dramatic music) 2 00:00:02,220 --> 00:00:04,010 Narrator: Freezing cold, 3 00:00:04,011 --> 00:00:04,841 (wind blows) 4 00:00:04,844 --> 00:00:07,254 oppressive heat, devastating drought. 5 00:00:09,472 --> 00:00:11,362 (thunder) 6 00:00:11,360 --> 00:00:13,890 Extreme climate change may have contributed 7 00:00:13,890 --> 00:00:16,180 to the extinction of the Neanderthals 8 00:00:16,180 --> 00:00:19,400 and allowed modern Homo sapiens to dominate the earth. 9 00:00:21,194 --> 00:00:23,944 (dramatic music) 10 00:00:25,720 --> 00:00:28,930 All life on earth is subject to the power of climate. 11 00:00:32,870 --> 00:00:36,570 Civilizations evolve or vanish forever. 12 00:00:36,569 --> 00:00:39,149 (wind blowing) 13 00:00:40,990 --> 00:00:43,760 Favorable climatic conditions support the rise 14 00:00:43,760 --> 00:00:47,540 of great empires and promote trade, prosperity, 15 00:00:47,540 --> 00:00:49,120 and artistic achievement. 16 00:00:50,630 --> 00:00:53,810 Adverse climatic events often lead to war 17 00:00:53,810 --> 00:00:56,080 and other human catastrophes. 18 00:00:56,081 --> 00:00:59,161 (storms and thunder) 19 00:01:01,785 --> 00:01:04,535 (dramatic music) 20 00:01:17,276 --> 00:01:19,606 (explosion) 21 00:01:20,920 --> 00:01:23,300 Almost 14 billion years ago. 22 00:01:23,300 --> 00:01:25,820 Immense forces created the universe. 23 00:01:27,070 --> 00:01:30,060 The Big Bang spawned vast galaxies. 24 00:01:30,060 --> 00:01:33,780 Each with millions and billions of stars, moons and planets. 25 00:01:38,870 --> 00:01:42,120 Among these, is one small blue planet. 26 00:01:42,120 --> 00:01:42,950 Our earth. 27 00:01:44,830 --> 00:01:48,600 Water, warmth, and the earth's protective atmosphere 28 00:01:48,600 --> 00:01:51,860 create something that may be unique in the universe. 29 00:01:51,860 --> 00:01:54,080 A climate that makes life possible. 30 00:01:55,420 --> 00:01:59,110 As the oceans formed and the continents drifted apart, 31 00:01:59,110 --> 00:02:01,000 the earth developed seasons. 32 00:02:02,210 --> 00:02:04,770 Temperature differences between land and water 33 00:02:04,770 --> 00:02:09,770 produced winds and land bridges shaped the ocean currents. 34 00:02:10,700 --> 00:02:14,130 But climate has always been prone to sudden change. 35 00:02:14,130 --> 00:02:17,290 Often with dramatic consequences for life on earth. 36 00:02:20,310 --> 00:02:24,320 65 million years ago, the dinosaurs were the unchallenged 37 00:02:24,320 --> 00:02:28,490 masters of the prehistoric world, until their sudden demise. 38 00:02:30,840 --> 00:02:33,410 A meteor strike triggered volcanic eruptions 39 00:02:33,410 --> 00:02:35,010 and earthquakes. 40 00:02:35,010 --> 00:02:38,030 The ensuing climatic chain reaction wiped out 41 00:02:38,030 --> 00:02:39,490 the giant reptiles. 42 00:02:39,490 --> 00:02:42,190 (dinosaur roars) 43 00:02:42,190 --> 00:02:43,580 (explosion) 44 00:02:43,580 --> 00:02:46,690 After the age of the dinosaurs the earth cooled. 45 00:02:49,560 --> 00:02:53,110 Climate change also affected our ancestors. 46 00:02:53,110 --> 00:02:54,750 Early hominids had to survive 47 00:02:54,750 --> 00:02:58,800 periods of both extreme heat and extreme cold. 48 00:02:58,800 --> 00:03:01,630 Most were unable to adapt and died out. 49 00:03:05,500 --> 00:03:09,650 Then over thousands of years, the polar ice caps expanded. 50 00:03:11,490 --> 00:03:13,310 As did the earth's alpine glaciers. 51 00:03:15,688 --> 00:03:16,568 (wind rushing) 52 00:03:16,570 --> 00:03:19,730 Around 60,000 BC, average temperatures 53 00:03:19,730 --> 00:03:23,040 were about five degrees colder than they are today. 54 00:03:23,040 --> 00:03:24,910 This had a huge impact. 55 00:03:24,906 --> 00:03:26,856 (wind blowing) 56 00:03:26,860 --> 00:03:30,080 Arctic sheet ice extended all the way to Europe. 57 00:03:30,082 --> 00:03:32,552 (whimsical music) 58 00:03:32,550 --> 00:03:34,320 So much water was frozen 59 00:03:34,320 --> 00:03:37,560 that sea levels became up to 100 meters lower. 60 00:03:38,975 --> 00:03:42,075 (foreboding music) 61 00:03:42,080 --> 00:03:45,220 The icy temperatures also affected the land. 62 00:03:45,220 --> 00:03:47,650 The ground was not only frozen solid 63 00:03:47,650 --> 00:03:50,270 but also extremely dry. 64 00:03:50,270 --> 00:03:51,460 Where the ice ended 65 00:03:51,460 --> 00:03:53,680 there were stretches of tundra and taiga. 66 00:03:56,266 --> 00:04:00,406 -: If you look at Western Europe as a place to live, 67 00:04:00,410 --> 00:04:02,820 you find that there are two challenges. 68 00:04:02,820 --> 00:04:06,250 One, you find that you have very cold conditions, 69 00:04:06,250 --> 00:04:07,720 particularly in winter. 70 00:04:07,720 --> 00:04:12,060 But during the summer because the ice is so far South 71 00:04:12,060 --> 00:04:13,840 you have this wonderful, 72 00:04:13,840 --> 00:04:16,120 sort of like high energy environment. 73 00:04:16,120 --> 00:04:20,000 So it doesn't stay stable for a very long period. 74 00:04:20,000 --> 00:04:23,200 And you have this sort of oscillating extremes 75 00:04:23,200 --> 00:04:24,690 going through the ice age. 76 00:04:24,690 --> 00:04:27,680 Which then stress any creatures that are living there 77 00:04:27,680 --> 00:04:28,780 at that time. 78 00:04:28,775 --> 00:04:29,615 (wind blowing) 79 00:04:29,617 --> 00:04:31,907 Narrator: But one homogenous was resistant 80 00:04:31,910 --> 00:04:33,250 to these stresses. 81 00:04:33,249 --> 00:04:35,699 (wind blowing) 82 00:04:35,700 --> 00:04:38,850 The Neanderthals were suited to these extreme conditions. 83 00:04:41,340 --> 00:04:44,210 They not only survived the climatic variations 84 00:04:44,210 --> 00:04:46,680 but developed an impressive range of skills. 85 00:04:48,016 --> 00:04:50,766 (wind whistling) 86 00:04:53,930 --> 00:04:56,770 Neanderthals were adept at hunting large animals 87 00:04:56,770 --> 00:04:58,950 and knew how to light fires. 88 00:04:58,950 --> 00:05:00,170 They were the first hominids 89 00:05:00,170 --> 00:05:02,610 to develop successful strategies for coping 90 00:05:02,610 --> 00:05:04,230 with climatic variation. 91 00:05:08,604 --> 00:05:12,604 (Frank speaks foreign language) 92 00:05:18,592 --> 00:05:19,752 (drums beating) 93 00:05:19,750 --> 00:05:21,570 Narrator: In the Neanderthal's caves, 94 00:05:21,570 --> 00:05:23,790 fires kept temperatures constant. 95 00:05:25,680 --> 00:05:28,330 They made warm clothes from animal skins. 96 00:05:33,500 --> 00:05:36,900 -: The key thing for surviving cold climates 97 00:05:36,900 --> 00:05:39,060 is to avoid frostbite. 98 00:05:39,060 --> 00:05:41,670 So the key things that you want to actually protect 99 00:05:41,670 --> 00:05:43,760 in cold climates, of course your fingers, 100 00:05:43,760 --> 00:05:47,260 your toes, your nose, and of course genitalia, 101 00:05:47,260 --> 00:05:49,300 if you happen to be a male. 102 00:05:49,295 --> 00:05:51,875 (wind blowing) 103 00:05:54,590 --> 00:05:57,040 Narrator: Neanderthals we're short and stocky. 104 00:05:58,220 --> 00:06:00,460 Their body surface area was quite small 105 00:06:00,460 --> 00:06:02,400 relative to their body mass. 106 00:06:02,400 --> 00:06:06,090 But they had lots of muscle which generates heat. 107 00:06:06,090 --> 00:06:09,520 They had the perfect anatomy for surviving in an ice age. 108 00:06:11,104 --> 00:06:13,694 (wind blowing) 109 00:06:15,690 --> 00:06:18,910 The Neanderthals main problem was their diet. 110 00:06:18,910 --> 00:06:21,580 They needed to consume large quantities of meat 111 00:06:21,580 --> 00:06:23,320 to sustain their muscle mass. 112 00:06:27,290 --> 00:06:29,640 So they preferred to hunt large animals. 113 00:06:32,300 --> 00:06:35,340 In summer when the ice receded for a few weeks 114 00:06:35,340 --> 00:06:37,580 they hunted mammoth and other big game. 115 00:06:40,640 --> 00:06:43,740 Hunting was physically demanding and dangerous, 116 00:06:43,740 --> 00:06:46,730 but Neanderthals needed animal protein and vitamins 117 00:06:46,730 --> 00:06:48,980 to survive the long winters. 118 00:06:48,980 --> 00:06:51,850 They often tracked their prey over long distances. 119 00:06:53,920 --> 00:06:56,720 -: When you look at a Neanderthal, they are tough, 120 00:06:56,720 --> 00:06:58,260 they are cold adapted. 121 00:06:58,260 --> 00:07:00,360 And you would expect them to survive 122 00:07:00,360 --> 00:07:02,590 and thrive in the ice ages. 123 00:07:03,450 --> 00:07:04,610 Narrator: And they did thrive 124 00:07:04,610 --> 00:07:06,660 while the climate was stable. 125 00:07:06,660 --> 00:07:09,400 But then quite suddenly it changed. 126 00:07:10,364 --> 00:07:12,494 (dramatic music) 127 00:07:12,490 --> 00:07:14,870 The climate has always been subject to large 128 00:07:14,870 --> 00:07:17,390 but predictable fluctuations. 129 00:07:17,390 --> 00:07:19,530 Most of these are caused by the sun, 130 00:07:19,530 --> 00:07:21,280 the center of our solar system. 131 00:07:23,440 --> 00:07:27,280 As the earth revolves the sun's rays strike its surface. 132 00:07:29,160 --> 00:07:31,970 At some times its orbit is more circular. 133 00:07:31,970 --> 00:07:33,520 At others, more elliptical. 134 00:07:34,580 --> 00:07:37,950 One orbital cycle takes 100,000 years. 135 00:07:38,860 --> 00:07:40,480 The angle of the earth's axis 136 00:07:40,480 --> 00:07:43,090 also moves in a 40,000 year cycle. 137 00:07:44,560 --> 00:07:48,350 These changes cause regular climatic variations on earth 138 00:07:48,350 --> 00:07:52,390 as the intensity of solar radiation increases and decreases. 139 00:07:54,410 --> 00:07:56,440 Other influences on the earth's climate 140 00:07:56,440 --> 00:07:59,820 such as fluctuations in sea currents are irregular. 141 00:08:02,340 --> 00:08:05,680 The Gulf Stream, for example, works like a giant heat pump. 142 00:08:05,681 --> 00:08:06,511 (water rushing) 143 00:08:06,514 --> 00:08:08,294 Moving warm water towards Europe. 144 00:08:10,410 --> 00:08:14,410 (Frank speaks foreign language) 145 00:08:33,420 --> 00:08:35,280 Narrator: Climatologists are investigating 146 00:08:35,280 --> 00:08:39,120 how changes in the Gulf Stream effected the Neanderthals. 147 00:08:39,120 --> 00:08:42,580 The answers lie hidden in Germany's Eifel mountains. 148 00:08:42,580 --> 00:08:45,180 Deep in the lakes that have formed in Maar, 149 00:08:45,180 --> 00:08:47,420 the craters of extinct volcanoes. 150 00:08:50,620 --> 00:08:53,750 These scientists are doing pioneering work. 151 00:08:53,750 --> 00:08:55,640 They use sophisticated technology 152 00:08:55,640 --> 00:08:58,380 to reconstruct the earth's prehistoric climate 153 00:08:58,380 --> 00:09:00,750 from its own natural records. 154 00:09:00,750 --> 00:09:02,410 Using a special drill, 155 00:09:02,410 --> 00:09:05,580 they're taking core samples from the sediment of Maar lakes 156 00:09:05,580 --> 00:09:07,290 and the Eifel Maars region. 157 00:09:10,307 --> 00:09:11,837 (boat creaking) 158 00:09:11,840 --> 00:09:13,470 For thousands of years 159 00:09:13,470 --> 00:09:16,250 pollen has settled in these oxygen poor waters 160 00:09:16,250 --> 00:09:18,090 and have been perfectly preserved. 161 00:09:26,670 --> 00:09:30,500 For scientists, the lakes provide a unique climatic record. 162 00:09:32,630 --> 00:09:35,160 The core samples are fragile. 163 00:09:35,160 --> 00:09:37,500 They have to be frozen with liquid nitrogen 164 00:09:37,500 --> 00:09:40,890 so they don't disintegrate on their way to the surface. 165 00:09:40,890 --> 00:09:42,590 (water bubbling) 166 00:09:42,590 --> 00:09:44,860 Every sample that's brought up in tact 167 00:09:44,860 --> 00:09:47,320 opens a door to the past. 168 00:09:47,320 --> 00:09:50,470 The pollen layers allow the scientists to draw conclusions 169 00:09:50,470 --> 00:09:53,500 about climatic conditions thousands of years ago. 170 00:09:53,495 --> 00:09:56,625 (water bubbling) 171 00:09:56,630 --> 00:09:58,490 The earth never forgets. 172 00:09:58,490 --> 00:10:00,960 And the climate leaves a unique footprint. 173 00:10:02,409 --> 00:10:05,879 (determined music) 174 00:10:05,878 --> 00:10:07,828 (scientists speak foreign language) 175 00:10:07,825 --> 00:10:08,725 (water and mud trickling) 176 00:10:08,730 --> 00:10:09,950 Narrator: Now the research team 177 00:10:09,950 --> 00:10:11,530 from the University of Mainz 178 00:10:11,530 --> 00:10:13,530 can start reading the climate chronicle. 179 00:10:17,472 --> 00:10:21,812 (scientists speak foreign language) 180 00:10:33,950 --> 00:10:36,500 Narrator: The older the period they want to investigate, 181 00:10:36,500 --> 00:10:39,200 the deeper the scientists need to drill. 182 00:10:39,200 --> 00:10:42,190 One millimeter of the sample equals one year. 183 00:10:43,810 --> 00:10:48,600 A meter long sample takes them back in time 1000 years. 184 00:10:48,600 --> 00:10:50,490 At a depth of 40 meters 185 00:10:50,490 --> 00:10:54,120 the researchers reach the era of the Neanderthals. 186 00:10:54,124 --> 00:10:57,494 (machinery whirring) 187 00:10:57,490 --> 00:11:01,110 The Eifel Maars are an ideal location for this research 188 00:11:01,110 --> 00:11:04,320 because the Neanderthals lived in this region. 189 00:11:04,320 --> 00:11:05,440 The Neander Valley, 190 00:11:05,440 --> 00:11:08,420 where the first Neanderthal skeleton was found 191 00:11:08,420 --> 00:11:10,740 is just 150 kilometers away. 192 00:11:12,780 --> 00:11:15,500 The core samples reveal what conditions were like 193 00:11:15,500 --> 00:11:16,750 for the Neanderthals 194 00:11:16,750 --> 00:11:18,920 when the Gulf Stream became erratic. 195 00:11:28,650 --> 00:11:32,370 The dark layers of earth indicate periods with mild climates 196 00:11:32,370 --> 00:11:34,820 and extensive forest cover. 197 00:11:34,820 --> 00:11:36,600 Lighter layers indicate periods 198 00:11:36,600 --> 00:11:38,840 when barren steps covered the area 199 00:11:38,840 --> 00:11:41,900 and summers were four degrees colder than today. 200 00:11:41,904 --> 00:11:43,644 (metal scrapping) 201 00:11:43,640 --> 00:11:47,790 About 60,000 years ago, the climate changed suddenly 202 00:11:47,790 --> 00:11:50,560 with dramatic consequences for the Neanderthals. 203 00:11:52,872 --> 00:11:57,212 (scientist speaks foreign language) 204 00:12:04,027 --> 00:12:05,217 (foreboding music) 205 00:12:05,224 --> 00:12:06,864 Narrator: There were 10 cold and hot phases 206 00:12:06,860 --> 00:12:08,770 in quick succession. 207 00:12:08,770 --> 00:12:12,420 The landscape and the vegetation changed rapidly. 208 00:12:12,420 --> 00:12:15,650 Humans and nature were under constant stress. 209 00:12:15,646 --> 00:12:18,976 (various nature sounds) 210 00:12:20,550 --> 00:12:24,290 This climate chaos pushed the Neanderthals to their limits 211 00:12:24,290 --> 00:12:26,530 and threatened their very existence. 212 00:12:29,756 --> 00:12:34,086 (scientist speaks foreign language) 213 00:12:49,876 --> 00:12:52,426 (water rushing) 214 00:12:52,430 --> 00:12:55,590 Narrator: First, the Neanderthals prey disappeared. 215 00:12:55,590 --> 00:12:59,280 Many animals were unable to find enough food and starved. 216 00:13:01,134 --> 00:13:01,974 (wind blowing) 217 00:13:01,967 --> 00:13:04,077 Others migrated away. 218 00:13:04,080 --> 00:13:08,090 Suddenly the Neanderthals were hunters with no prey. 219 00:13:08,090 --> 00:13:11,290 At the same time, a competitor moved into their territory. 220 00:13:16,030 --> 00:13:19,630 Homo sapiens evolved in the warm climate of East Africa 221 00:13:19,630 --> 00:13:22,230 and slowly migrated all the way to Europe. 222 00:13:23,467 --> 00:13:26,127 (hopeful music) 223 00:13:27,350 --> 00:13:29,750 The newcomers seemed completely unsuited 224 00:13:29,750 --> 00:13:31,810 to these harsh and changeable climate. 225 00:13:38,770 --> 00:13:41,140 Homo sapiens was tall and slender 226 00:13:41,140 --> 00:13:43,210 with long arms and legs. 227 00:13:43,210 --> 00:13:46,390 This build made them extremely susceptible to cold. 228 00:13:48,600 --> 00:13:51,830 But they overcame this disadvantage thanks to a new skill. 229 00:13:53,840 --> 00:13:56,270 -: It's been argued that Homo sapiens 230 00:13:56,270 --> 00:13:58,250 had a very different shoulder, 231 00:13:58,250 --> 00:14:01,050 so they could actually throw spears. 232 00:14:01,050 --> 00:14:02,860 Whereas if we look at the shoulders of Neanderthals 233 00:14:02,863 --> 00:14:05,033 they're so big and chunky 234 00:14:05,030 --> 00:14:08,270 that actually that ability to throw probably wasn't there. 235 00:14:08,270 --> 00:14:09,590 And actually they were much more likely 236 00:14:09,590 --> 00:14:11,760 to be thrusting spears. 237 00:14:12,640 --> 00:14:14,930 Narrator: Throwing spears allowed Homo sapiens 238 00:14:14,930 --> 00:14:17,620 to kill much faster animals from a distance. 239 00:14:19,610 --> 00:14:22,310 The revolutionary invention made hunting for meat 240 00:14:22,310 --> 00:14:23,960 much easier. 241 00:14:23,956 --> 00:14:26,706 (dramatic music) 242 00:14:33,870 --> 00:14:36,920 The Neanderthals who'd been the masters of Europe 243 00:14:36,920 --> 00:14:38,590 lost their fight for survival. 244 00:14:39,480 --> 00:14:43,000 They weren't adaptable enough to save their species. 245 00:14:43,000 --> 00:14:45,380 The last of them died on the rock of Gibraltar 246 00:14:45,380 --> 00:14:47,450 about 24,000 years ago. 247 00:14:52,560 --> 00:14:55,320 The clear winner in this time of climate change 248 00:14:55,320 --> 00:14:56,680 was Homo sapiens. 249 00:14:57,570 --> 00:15:01,070 We still share about 99% of our genetic material 250 00:15:01,070 --> 00:15:02,710 with these ancient humans. 251 00:15:07,320 --> 00:15:10,680 After migrating to Europe from Africa, Homo sapiens 252 00:15:10,680 --> 00:15:12,600 spread to India and Asia, 253 00:15:12,600 --> 00:15:16,000 then via land bridges to Australia and America. 254 00:15:16,950 --> 00:15:18,800 During this mass migration, 255 00:15:18,800 --> 00:15:21,030 they settled in some of the most remote corners 256 00:15:21,030 --> 00:15:22,110 of the earth. 257 00:15:25,734 --> 00:15:27,584 -: The key to that was the adaptability. 258 00:15:27,580 --> 00:15:30,190 The ability to understand the environment, 259 00:15:30,190 --> 00:15:33,810 how it's changing and to work with large social groups 260 00:15:33,810 --> 00:15:37,560 to be able to actually deal with that changing landscape. 261 00:15:37,560 --> 00:15:38,440 And for me, 262 00:15:38,440 --> 00:15:42,450 this is the point where humans first started to adapt 263 00:15:42,450 --> 00:15:45,740 to the climate and use the climate for their own good. 264 00:15:47,670 --> 00:15:50,880 Narrator: During a time of unprecedented climate chaos 265 00:15:50,880 --> 00:15:53,490 humans developed a unique ability. 266 00:15:53,490 --> 00:15:56,320 Surviving in changing climates. 267 00:15:56,320 --> 00:15:58,850 This allowed them to withstand the last millennia 268 00:15:58,850 --> 00:16:00,210 of the ice age. 269 00:16:00,210 --> 00:16:01,940 A time of extreme cold. 270 00:16:08,197 --> 00:16:12,397 The ice age gradually came to an end around 17,000 BC 271 00:16:12,400 --> 00:16:14,340 due to changes in the earth's orbit. 272 00:16:16,940 --> 00:16:19,290 As the earth moved closer to the sun, 273 00:16:19,290 --> 00:16:20,990 life changed dramatically. 274 00:16:25,450 --> 00:16:28,770 The sunlight grew stronger, particularly in summer. 275 00:16:31,720 --> 00:16:35,170 The icy planet was about to experience a global spring. 276 00:16:38,810 --> 00:16:40,420 It took several thousand years 277 00:16:40,420 --> 00:16:42,620 for the sun to warm the entire globe. 278 00:16:46,663 --> 00:16:49,013 As the earth's climate became much milder, 279 00:16:49,010 --> 00:16:52,830 a new era began and has continued until the present day. 280 00:16:55,712 --> 00:16:58,462 (dramatic music) 281 00:17:01,780 --> 00:17:05,490 Warmer temperatures lead to changes in the environment. 282 00:17:05,492 --> 00:17:07,392 (water dripping) 283 00:17:07,387 --> 00:17:08,217 (ice cracking) 284 00:17:08,220 --> 00:17:11,000 First, the ice sheets in the Arctic and Antarctic 285 00:17:11,000 --> 00:17:12,080 began to melt. 286 00:17:12,970 --> 00:17:15,190 The oceans also began to warm 287 00:17:15,190 --> 00:17:18,140 and the Gulf Stream began to flow again. 288 00:17:18,143 --> 00:17:20,393 (water rushing) 289 00:17:20,390 --> 00:17:22,060 As temperatures rose, 290 00:17:22,060 --> 00:17:25,800 more and more moisture evaporated into the atmosphere. 291 00:17:25,800 --> 00:17:27,710 This led to regular rainfall, 292 00:17:27,710 --> 00:17:30,290 which triggered a burst of plant growth. 293 00:17:30,285 --> 00:17:32,625 (birds chirping) 294 00:17:32,630 --> 00:17:35,450 There was increased biodiversity. 295 00:17:35,450 --> 00:17:39,270 Mixed forests spread across Europe and North America. 296 00:17:39,270 --> 00:17:42,710 And sub-tropical forests flourished closer to the equator. 297 00:17:44,580 --> 00:17:48,120 New animal species started to populate the fertile plains. 298 00:17:48,120 --> 00:17:51,300 (elephant trumpeting) 299 00:17:51,298 --> 00:17:55,378 (Detlef speaks foreign language) 300 00:18:10,830 --> 00:18:13,300 Narrator: Along the Tigris and Euphrates rivers, 301 00:18:13,300 --> 00:18:17,130 and in the Eastern Mediterranean, abundant natural resources 302 00:18:17,130 --> 00:18:19,460 created ideal living conditions. 303 00:18:20,643 --> 00:18:23,543 (swooshing sound) 304 00:18:23,540 --> 00:18:25,730 At the ancient site of Gobekli Tepe, 305 00:18:25,730 --> 00:18:29,760 are 60 stone steels, engraved with the images of animals, 306 00:18:29,760 --> 00:18:33,440 including foxes, wild boar, and waterbirds. 307 00:18:36,665 --> 00:18:39,385 (fire whooshing) 308 00:18:39,390 --> 00:18:42,140 Nomadic peoples may have worshiped these figures 309 00:18:42,140 --> 00:18:45,580 because wild animals supplied them with meat and skins. 310 00:18:45,576 --> 00:18:46,746 (fire whooshing) 311 00:18:46,746 --> 00:18:49,396 (mystical music) 312 00:18:49,402 --> 00:18:53,492 (Detlef speaks foreign language) 313 00:19:09,466 --> 00:19:10,376 (swooshing sound) 314 00:19:10,380 --> 00:19:13,220 Narrator: Also of great benefit to humans and animals, 315 00:19:13,220 --> 00:19:15,910 were the wild grains growing in the warm sunshine 316 00:19:15,910 --> 00:19:17,760 of the Fertile Crescent. 317 00:19:17,759 --> 00:19:19,969 (crickets singing) 318 00:19:19,970 --> 00:19:24,380 Einkorn, spelt, and emmer grew all across the Middle East. 319 00:19:24,380 --> 00:19:27,340 They're among the oldest grain varieties on earth. 320 00:19:28,490 --> 00:19:32,580 Easily stored, these grains could be eaten all year round. 321 00:19:32,580 --> 00:19:36,030 And so provided humans with a reliable food source. 322 00:19:36,028 --> 00:19:38,698 (hopeful music) 323 00:19:45,520 --> 00:19:47,790 As the seasons became more regular, 324 00:19:47,790 --> 00:19:51,160 humans began to cultivate these wild cereals. 325 00:19:51,160 --> 00:19:53,560 They observed the cycles of nature 326 00:19:53,560 --> 00:19:56,700 and by experimenting soon learned the best times 327 00:19:56,700 --> 00:19:57,820 to sow crops. 328 00:20:01,570 --> 00:20:04,990 Agriculture revolutionized prehistoric societies. 329 00:20:04,990 --> 00:20:05,820 (pensive music) 330 00:20:05,823 --> 00:20:07,963 Many abandoned their nomadic lives 331 00:20:07,960 --> 00:20:10,610 and became farmers and cattle breeders. 332 00:20:14,560 --> 00:20:15,780 For the first time, 333 00:20:15,780 --> 00:20:19,420 humans began to settle down and build villages. 334 00:20:19,420 --> 00:20:21,960 They no longer needed to travel, to find food. 335 00:20:25,075 --> 00:20:26,115 (hay crinkling) 336 00:20:26,120 --> 00:20:29,110 -: Prior to agriculture, people were hunter/gatherers 337 00:20:29,110 --> 00:20:30,380 and moving around. 338 00:20:30,380 --> 00:20:33,890 And everybody from the very eldest to the very youngest 339 00:20:33,890 --> 00:20:38,200 were all concentrating on collecting and hunting for food, 340 00:20:38,200 --> 00:20:40,450 because that was essential. 341 00:20:40,450 --> 00:20:42,980 As soon as you have the agricultural revolution 342 00:20:42,980 --> 00:20:46,210 and agriculture starts, suddenly, 343 00:20:46,210 --> 00:20:49,410 not everyone is involved in food production. 344 00:20:49,410 --> 00:20:51,740 And allowing people to have the freedom 345 00:20:51,740 --> 00:20:55,740 to actually do other things, allow society to build. 346 00:20:55,739 --> 00:20:58,489 (sheep bleating) 347 00:20:59,680 --> 00:21:01,600 Narrator: Once they'd settled in villages 348 00:21:01,600 --> 00:21:04,690 people began to specialize and develop their skills. 349 00:21:06,710 --> 00:21:08,590 They invented techniques that allowed them 350 00:21:08,590 --> 00:21:11,790 to make new valuable objects for their communities. 351 00:21:13,085 --> 00:21:15,185 (birds chirping) 352 00:21:15,190 --> 00:21:17,720 -: You have specialists who are then farmers, 353 00:21:17,720 --> 00:21:20,830 you have specialists who are then looking after cattle 354 00:21:20,830 --> 00:21:23,510 and goats and other domesticated animals. 355 00:21:23,510 --> 00:21:26,610 And then other people can then develop specializations. 356 00:21:26,610 --> 00:21:29,630 So for example, if you're settled in one place 357 00:21:29,630 --> 00:21:32,890 then you will want people who are specialized in building. 358 00:21:32,890 --> 00:21:35,910 So you can actually then have houses built 359 00:21:35,910 --> 00:21:37,860 or you can have buildings built. 360 00:21:37,860 --> 00:21:40,300 And so you then start to free up people 361 00:21:40,300 --> 00:21:42,920 from the manual labor of just producing food. 362 00:21:42,922 --> 00:21:43,852 (birds chirping) 363 00:21:43,850 --> 00:21:45,950 Narrator: Pottery, metalwork, and weeding 364 00:21:45,950 --> 00:21:48,050 changed people's lives. 365 00:21:48,050 --> 00:21:51,310 So did more humble inventions, like bread and beer. 366 00:21:52,551 --> 00:21:55,301 (birds chirping) 367 00:21:56,849 --> 00:21:57,849 Over the centuries, 368 00:21:57,850 --> 00:22:00,340 villages grew into towns. 369 00:22:00,340 --> 00:22:02,490 One of the oldest is Jericho, 370 00:22:02,490 --> 00:22:04,140 on the banks of the river Jordan. 371 00:22:05,860 --> 00:22:07,290 Other cities in the area, 372 00:22:07,290 --> 00:22:10,170 were Catalhoyuk, Eridu, and Ur. 373 00:22:11,310 --> 00:22:14,800 This cradle of civilization benefited from a long period 374 00:22:14,800 --> 00:22:17,340 of favorable climatic conditions. 375 00:22:17,335 --> 00:22:19,685 (triumphant music) 376 00:22:19,691 --> 00:22:23,771 (Detlef speaks foreign language) 377 00:22:46,375 --> 00:22:48,335 (foreboding music) 378 00:22:48,344 --> 00:22:49,244 Narrator: Around the same time, 379 00:22:49,240 --> 00:22:52,300 a disaster was looming in North America. 380 00:22:52,300 --> 00:22:54,800 Part of the continental ice sheet melted 381 00:22:54,800 --> 00:22:57,290 and created a vast Lake. 382 00:22:57,290 --> 00:22:59,930 It continued to grow until it covered an area 383 00:22:59,930 --> 00:23:03,130 of 440,000 square kilometers. 384 00:23:03,130 --> 00:23:05,920 Far bigger than any lake existing today. 385 00:23:07,740 --> 00:23:10,760 The intense sunlight caused the lake to grow 386 00:23:10,760 --> 00:23:13,290 as more and more meltwater flowed into it 387 00:23:13,290 --> 00:23:14,450 from the mountains. 388 00:23:17,102 --> 00:23:19,102 (swooshing sound) 389 00:23:19,101 --> 00:23:19,931 (ice cracking) 390 00:23:19,934 --> 00:23:24,524 At first ice barriers held back this huge volume of water. 391 00:23:24,519 --> 00:23:27,939 (ice sheets collapsing) 392 00:23:29,490 --> 00:23:34,060 But around 6,200 BC, they too began to melt 393 00:23:34,060 --> 00:23:35,800 and disaster was inevitable. 394 00:23:39,650 --> 00:23:42,460 The barriers around Lake Agassiz collapsed. 395 00:23:44,656 --> 00:23:47,496 (water rushing) 396 00:23:47,500 --> 00:23:50,610 A huge amount of icy water was released. 397 00:23:50,610 --> 00:23:53,340 It flooded large parts of North America 398 00:23:53,340 --> 00:23:55,400 and eventually drained into the Atlantic. 399 00:23:59,750 --> 00:24:02,010 The immense inflow of cold water 400 00:24:02,010 --> 00:24:04,090 upset the currents in the Atlantic. 401 00:24:08,030 --> 00:24:09,930 It disrupted the Gulf Stream 402 00:24:09,930 --> 00:24:12,000 which ceased to have a warming effect. 403 00:24:14,000 --> 00:24:16,110 Temperatures dropped all across Europe. 404 00:24:17,010 --> 00:24:18,640 In the Fertile Crescent 405 00:24:18,640 --> 00:24:21,400 where agriculture had so recently allowed humans 406 00:24:21,400 --> 00:24:23,250 to make enormous progress, 407 00:24:23,250 --> 00:24:26,060 the weather suddenly became cold and dry. 408 00:24:28,080 --> 00:24:32,050 This led to devastating droughts and crops failed. 409 00:24:32,048 --> 00:24:34,868 (wind blowing) 410 00:24:34,869 --> 00:24:38,219 The new agrarian societies lost their livelihoods. 411 00:24:45,173 --> 00:24:49,263 (Detlef speaks foreign language) 412 00:25:05,610 --> 00:25:07,710 Narrator: The first ever climate refugees, 413 00:25:07,710 --> 00:25:10,380 came from the Eastern Mediterranean. 414 00:25:10,380 --> 00:25:13,830 Many thousands left in search of a new Eden. 415 00:25:13,831 --> 00:25:16,581 (birds chirping) 416 00:25:17,430 --> 00:25:19,470 Some ventured, as far as Europe, 417 00:25:19,470 --> 00:25:21,880 where temperatures were still relatively mild 418 00:25:21,880 --> 00:25:25,590 and fertile soil promised ideal conditions for settlement. 419 00:25:29,490 --> 00:25:31,100 Others stayed in the Middle East, 420 00:25:31,100 --> 00:25:32,390 but moved further south. 421 00:25:33,280 --> 00:25:36,960 Everywhere they went, these migrants introduced agriculture. 422 00:25:41,920 --> 00:25:45,300 They preferred to settle along rivers or on the coast. 423 00:25:45,300 --> 00:25:49,480 Anywhere they had a reliable supply of fresh water and food. 424 00:25:49,480 --> 00:25:51,630 But even in moderate climate zones, 425 00:25:51,630 --> 00:25:54,560 the settlers were not safe. 426 00:25:58,562 --> 00:26:01,132 The dangers caused by the North American meltwater 427 00:26:01,130 --> 00:26:02,890 were far from over. 428 00:26:02,890 --> 00:26:06,010 Sea levels rose 120 meters. 429 00:26:06,013 --> 00:26:08,933 (foreboding music) 430 00:26:10,790 --> 00:26:11,880 All over the world 431 00:26:11,880 --> 00:26:14,560 humans found their very existence threatened. 432 00:26:15,674 --> 00:26:17,994 (water rushing) 433 00:26:17,990 --> 00:26:21,860 Gradually the sea reclaimed vast tracks of fertile land, 434 00:26:21,860 --> 00:26:24,320 and rising sea levels flooded settlements 435 00:26:24,320 --> 00:26:26,410 in river deltas and along coasts. 436 00:26:35,410 --> 00:26:37,040 The Bible tells of these events 437 00:26:37,040 --> 00:26:39,120 in one of its best known stories. 438 00:26:39,970 --> 00:26:43,740 God told Noah to gather all the world's animals on his Ark, 439 00:26:43,740 --> 00:26:46,470 two of each kind and take them to safety. 440 00:26:49,540 --> 00:26:51,640 The rest of humanity was to be punished 441 00:26:51,640 --> 00:26:53,400 in a devastating deluge. 442 00:26:53,404 --> 00:26:54,994 (lion roars) 443 00:26:54,992 --> 00:26:55,832 (people screaming) 444 00:26:55,825 --> 00:26:57,055 Noah did God's bidding. 445 00:27:01,410 --> 00:27:04,730 -: If you look into almost all human societies 446 00:27:04,730 --> 00:27:07,370 there are stories about the great flood. 447 00:27:07,367 --> 00:27:11,407 And the reason for this is because key period of time 448 00:27:11,410 --> 00:27:14,970 between 10,000 and 5,000 years ago, 449 00:27:14,970 --> 00:27:18,750 after the last ice age, sea levels continue to rise. 450 00:27:18,750 --> 00:27:22,330 And that flood, all those societies that are affected 451 00:27:22,330 --> 00:27:26,080 by that sea level rise has really impinged upon our psyche 452 00:27:26,080 --> 00:27:28,780 and has embedded itself in our stories 453 00:27:28,780 --> 00:27:30,670 about the end of the world. 454 00:27:30,665 --> 00:27:32,745 (water rushing) 455 00:27:32,750 --> 00:27:34,400 Narrator: The Bible is not the only book 456 00:27:34,400 --> 00:27:36,740 that tells of a great flood and an ark. 457 00:27:37,699 --> 00:27:40,869 (waves rippling) 458 00:27:40,870 --> 00:27:42,810 The mountainous waves and the deluge 459 00:27:42,810 --> 00:27:44,610 that destroyed everything in its path 460 00:27:44,610 --> 00:27:47,890 are also vividly described in the Epic of Gilgamesh 461 00:27:47,890 --> 00:27:51,310 from ancient Mesopotamia and the Quran. 462 00:27:51,312 --> 00:27:53,982 (water rushing) 463 00:28:01,580 --> 00:28:03,550 Tribal peoples in South America 464 00:28:03,550 --> 00:28:06,660 also tell of a vast flood that covered the entire earth. 465 00:28:07,530 --> 00:28:09,600 It is said that people only survived 466 00:28:09,600 --> 00:28:11,410 by fleeing to the mountain tops. 467 00:28:16,340 --> 00:28:19,690 Indigenous Australians also refer to a great flood. 468 00:28:20,610 --> 00:28:22,360 The dramatic rise in sea levels 469 00:28:22,360 --> 00:28:23,870 thousands of years ago 470 00:28:23,870 --> 00:28:26,170 has become part of our collective memory. 471 00:28:28,580 --> 00:28:30,900 -: All around the world where people were 472 00:28:30,900 --> 00:28:35,570 sea level rose and rose and rose until about 5,000 years. 473 00:28:35,570 --> 00:28:37,610 And we know that there are lots of areas 474 00:28:37,610 --> 00:28:41,440 that are completely flooded now that had society. 475 00:28:41,440 --> 00:28:46,440 So you can see cities underneath the sea close to mortar. 476 00:28:46,860 --> 00:28:47,720 And in Japan. 477 00:28:47,720 --> 00:28:49,640 We know that off the coast 478 00:28:49,640 --> 00:28:53,480 of the United Kingdom in the North sea is Doggerland. 479 00:28:53,480 --> 00:28:55,550 And when you actually survey Doggerland, 480 00:28:55,550 --> 00:29:00,050 it has the imprint of villages of neolithic tribes 481 00:29:00,050 --> 00:29:02,510 that used to live there that were flooded out. 482 00:29:02,510 --> 00:29:04,370 (dramatic music) 483 00:29:04,370 --> 00:29:05,710 Narrator: The rising sea levels 484 00:29:05,710 --> 00:29:08,050 change the map of the world. 485 00:29:08,050 --> 00:29:11,210 In North America, Hudson Bay and the Great Lakes 486 00:29:11,210 --> 00:29:12,800 came into being. 487 00:29:12,800 --> 00:29:15,720 In Northern Europe, the Baltic Sea was formed. 488 00:29:17,510 --> 00:29:21,630 Japan, Indonesia and Australia became islands. 489 00:29:25,420 --> 00:29:29,580 The great glacier melt did not always bring devastation. 490 00:29:29,580 --> 00:29:32,140 One place that benefited was the Sahara. 491 00:29:34,076 --> 00:29:36,656 (sand blowing) 492 00:29:37,520 --> 00:29:42,060 Today it's a hot, arid and inhospitable region. 493 00:29:42,060 --> 00:29:44,820 But the Sahara may once have been very different. 494 00:29:47,020 --> 00:29:48,840 (sand sifting) 495 00:29:48,841 --> 00:29:52,411 At an ancient site on the (indistinct) plateau in Egypt, 496 00:29:52,410 --> 00:29:55,090 archeologists have uncovered surprising scenes 497 00:29:55,090 --> 00:29:57,400 from prehistoric times. 498 00:29:57,399 --> 00:30:00,229 (dramatic music) 499 00:30:01,420 --> 00:30:03,930 They found stenciled hand prints 500 00:30:03,930 --> 00:30:07,530 which were probably made by nomads or traders. 501 00:30:07,530 --> 00:30:10,240 An adjacent cave has rock paintings of humans 502 00:30:10,240 --> 00:30:13,630 standing alone and in groups. 503 00:30:16,940 --> 00:30:17,770 All this art 504 00:30:17,773 --> 00:30:20,373 was produced during the time of the great flood. 505 00:30:21,400 --> 00:30:23,400 While much of the world suffered, 506 00:30:23,400 --> 00:30:26,440 the Sahara appears to have been teeming with life. 507 00:30:27,280 --> 00:30:31,120 Many people lived here and animal life was abundant. 508 00:30:31,120 --> 00:30:33,160 There were antelopes and lions. 509 00:30:37,580 --> 00:30:38,950 And even giraffes. 510 00:30:42,440 --> 00:30:45,290 What is now the world's largest sandy desert 511 00:30:45,290 --> 00:30:47,520 was once a fertile savannah. 512 00:30:47,517 --> 00:30:50,427 (water trickling) 513 00:30:52,500 --> 00:30:56,220 It was home to herds of animals that roamed rich pastures 514 00:30:56,220 --> 00:30:59,420 fed by a vast network of rivers and lakes. 515 00:31:05,810 --> 00:31:07,870 Change in this region's climate 516 00:31:07,870 --> 00:31:10,330 was influenced by another factor. 517 00:31:10,330 --> 00:31:11,750 Monsoon winds. 518 00:31:14,030 --> 00:31:17,740 The Northern hemisphere was receiving more heat from the sun 519 00:31:17,740 --> 00:31:20,650 because of a change in the tilt of the Earth's axis. 520 00:31:24,640 --> 00:31:27,740 Land masses store more heat than oceans, 521 00:31:27,740 --> 00:31:31,470 creating temperature differences that produce monsoon winds 522 00:31:31,470 --> 00:31:35,130 which carry cool, moist air inland. 523 00:31:35,130 --> 00:31:37,740 These winds brought rain and abundant life 524 00:31:37,740 --> 00:31:39,020 to what is now desert. 525 00:31:41,000 --> 00:31:42,930 -: If we look at the Sahara, 526 00:31:42,930 --> 00:31:46,650 we find that there is a huge period of time 527 00:31:46,650 --> 00:31:49,070 between about 12,000 years ago 528 00:31:49,070 --> 00:31:51,160 and 5,500 years ago 529 00:31:51,160 --> 00:31:53,070 where the Sahara was green. 530 00:31:53,070 --> 00:31:56,910 And by that we mean that people were able to live there. 531 00:31:56,910 --> 00:31:59,410 And so we find archeological finds 532 00:31:59,410 --> 00:32:01,010 all the way through the Sahara, 533 00:32:01,010 --> 00:32:03,030 showing that people thrived there, 534 00:32:03,030 --> 00:32:05,610 there was clearly enough food, 535 00:32:05,610 --> 00:32:08,310 agriculture was actually developing there. 536 00:32:08,310 --> 00:32:12,630 And then slowly from about 7,000 years onwards 537 00:32:12,630 --> 00:32:15,580 the Sahara started to expand. 538 00:32:15,577 --> 00:32:18,097 (gentle music) 539 00:32:18,100 --> 00:32:20,370 Narrator: But this flowering of the Sahara 540 00:32:20,370 --> 00:32:24,000 and the abundance of water, wildlife and food plants 541 00:32:23,995 --> 00:32:26,185 was fated not to last. 542 00:32:30,350 --> 00:32:33,570 The fertile savannah land became a sandy desert. 543 00:32:33,569 --> 00:32:37,339 Harsh, barren and largely uninhabited. 544 00:32:37,335 --> 00:32:39,995 (wind blowing) 545 00:32:41,138 --> 00:32:42,798 The subtropical monsoon winds 546 00:32:42,800 --> 00:32:45,000 lasted only a relatively short time, 547 00:32:45,000 --> 00:32:47,170 until the earth's axis shifted again. 548 00:32:48,260 --> 00:32:52,000 As the sun's heat decreased, the monsoons lost their power. 549 00:32:53,501 --> 00:32:56,251 (wind rushing) 550 00:33:06,730 --> 00:33:08,910 When plants die from drought, 551 00:33:08,910 --> 00:33:11,800 less moisture is retained in the soil. 552 00:33:11,800 --> 00:33:14,670 This accelerates the degradation of the land 553 00:33:14,670 --> 00:33:16,710 and deserts form surprisingly quickly. 554 00:33:18,993 --> 00:33:22,993 (Frank speaks foreign language) 555 00:33:37,550 --> 00:33:39,900 Narrator: We know when the Sahara became a desert 556 00:33:39,900 --> 00:33:42,930 thanks to this ancient burial site in Niger 557 00:33:42,930 --> 00:33:45,170 on what was once the shores of Lake Obero. 558 00:33:48,150 --> 00:33:51,050 For many generations, the dead were buried here 559 00:33:51,050 --> 00:33:53,640 along with objects, such as bone fish hooks 560 00:33:53,640 --> 00:33:56,160 and jewelry made from hippopotamus tusks. 561 00:33:59,670 --> 00:34:02,370 But the burials seem to have ended quite abruptly 562 00:34:02,370 --> 00:34:05,010 in around 3,500 BC. 563 00:34:06,630 --> 00:34:08,150 When the lake dried up, 564 00:34:08,150 --> 00:34:10,650 the inhabitants abandoned the burial site 565 00:34:10,650 --> 00:34:12,690 and all trace of them disappears. 566 00:34:16,640 --> 00:34:19,970 When the rain stopped, they had to leave. 567 00:34:19,970 --> 00:34:22,850 Drought had completely transformed the landscape 568 00:34:24,740 --> 00:34:27,230 and this didn't just happen in the Sahara. 569 00:34:29,500 --> 00:34:32,120 All over the world, deserts began to form. 570 00:34:33,670 --> 00:34:35,580 The (indistinct) in Central Asia, 571 00:34:36,620 --> 00:34:38,000 Australia's Red Centre 572 00:34:39,690 --> 00:34:43,320 the Namib and the Kalahari deserts in Southern Africa. 573 00:34:43,318 --> 00:34:46,148 (dramatic music) 574 00:34:48,800 --> 00:34:50,610 This was the last major shift 575 00:34:50,610 --> 00:34:53,770 toward the earth's current climatic patterns. 576 00:34:53,770 --> 00:34:56,280 That small change in the tilt of the globe 577 00:34:56,280 --> 00:34:59,600 caused the rains to stop in many subtropical regions. 578 00:35:01,705 --> 00:35:04,365 (wind blowing) 579 00:35:05,620 --> 00:35:09,510 Once again, climatic change forced thousands to migrate. 580 00:35:11,720 --> 00:35:13,520 There was an exodus from the Sahara 581 00:35:13,520 --> 00:35:16,050 towards a fertile region in Northern Africa. 582 00:35:18,680 --> 00:35:22,580 While inland rivers had dried up, the Nile in lower Egypt 583 00:35:22,580 --> 00:35:25,270 was still a reliable source of water. 584 00:35:25,270 --> 00:35:28,460 On its banks, the migrants found fertile soils. 585 00:35:32,110 --> 00:35:34,900 The Nile Valley is Egypt's green heart. 586 00:35:34,900 --> 00:35:39,490 A verdant floodplain over 1100 kilometers in length. 587 00:35:39,490 --> 00:35:43,120 The great river provides ample water to irrigate the valley, 588 00:35:43,120 --> 00:35:44,760 which is surrounded by desert. 589 00:35:49,470 --> 00:35:52,980 Every summer, heavy rains in the Ethiopian Highlands 590 00:35:52,980 --> 00:35:55,050 cause the river to break its banks. 591 00:36:00,450 --> 00:36:03,870 In September and October, the flood waters recede, 592 00:36:03,870 --> 00:36:06,760 the soil dries out and the fields can be tilled. 593 00:36:10,880 --> 00:36:13,450 While they follow a regular yearly cycle, 594 00:36:13,450 --> 00:36:16,370 the Nile floods can be extreme. 595 00:36:16,370 --> 00:36:19,500 The early settlers had to adapt to these conditions. 596 00:36:20,840 --> 00:36:23,650 The climate refugees became skillful farmers 597 00:36:23,650 --> 00:36:25,450 and hydraulic engineers. 598 00:36:25,452 --> 00:36:26,292 (birds chirping) 599 00:36:26,285 --> 00:36:28,635 The ancient Egyptians knew how to use every drop 600 00:36:28,640 --> 00:36:31,550 of the precious monsoon rains for their fields. 601 00:36:31,549 --> 00:36:33,709 (water flowing) 602 00:36:33,710 --> 00:36:35,740 Water flowed through a system of canals. 603 00:36:38,300 --> 00:36:40,640 To direct the water to where it was needed 604 00:36:40,640 --> 00:36:44,740 they used lochs and counterweighted buckets. 605 00:36:45,586 --> 00:36:48,496 (water rippling) 606 00:36:50,460 --> 00:36:52,860 This sophisticated irrigation system 607 00:36:52,860 --> 00:36:54,770 helped create an economic boom. 608 00:36:56,070 --> 00:36:58,320 The Nile made the region prosperous 609 00:36:58,320 --> 00:37:00,640 and fed increasing numbers of people. 610 00:37:00,643 --> 00:37:02,983 (cow moos) 611 00:37:04,160 --> 00:37:07,450 Egypt's first cities sprang up along the banks of the Nile. 612 00:37:08,613 --> 00:37:12,163 (birds chirping) 613 00:37:12,163 --> 00:37:16,333 (Gunther speaks foreign language) 614 00:37:22,770 --> 00:37:24,370 Narrator: Simple settlements soon evolved 615 00:37:24,367 --> 00:37:27,047 into Egypt's first kingdom. 616 00:37:27,050 --> 00:37:30,400 But the social and political system continued to revolve 617 00:37:30,400 --> 00:37:33,420 around safeguarding and managing the water supply. 618 00:37:34,766 --> 00:37:37,426 (hopeful music) 619 00:37:39,400 --> 00:37:40,600 (swooshing sound) 620 00:37:40,600 --> 00:37:43,950 This was done with the help of an ingenious invention, 621 00:37:43,950 --> 00:37:47,590 the nilometer, a step structure used to measure the level 622 00:37:47,590 --> 00:37:49,470 of the Nile flood borders. 623 00:37:49,470 --> 00:37:51,610 The measurements were used to predict the effect 624 00:37:51,610 --> 00:37:53,490 of the flood each year. 625 00:37:53,488 --> 00:37:56,318 (water rushing) 626 00:37:58,440 --> 00:38:00,640 The Egyptian calendar was also based 627 00:38:00,640 --> 00:38:02,590 on this annual flooding. 628 00:38:02,590 --> 00:38:05,330 Akhet was the season of inundation, 629 00:38:05,330 --> 00:38:07,810 Peret was the season of emergence, 630 00:38:07,810 --> 00:38:10,610 and Shemu was the harvest season. 631 00:38:10,614 --> 00:38:13,364 (grain sifting) 632 00:38:14,763 --> 00:38:19,013 (Gunther speaks foreign language) 633 00:38:37,730 --> 00:38:40,660 Narrator: This most famous of ancient civilizations 634 00:38:40,660 --> 00:38:43,170 was the product of favorable climatic conditions 635 00:38:43,170 --> 00:38:44,930 in the Nile Valley. 636 00:38:44,930 --> 00:38:47,340 The pharaohs were able to build and maintain 637 00:38:47,340 --> 00:38:50,790 the Egyptian empire over almost 3000 years 638 00:38:50,790 --> 00:38:55,460 because the Nile provided all the necessary resources. 639 00:38:59,290 --> 00:39:01,840 -: The fundamental resource you need 640 00:39:01,840 --> 00:39:06,660 to build an empire is food and water. 641 00:39:06,660 --> 00:39:10,290 If you actually want artisans to build temples, 642 00:39:10,290 --> 00:39:13,010 you want soldiers to go off and fight wars for you, 643 00:39:13,010 --> 00:39:16,240 you have to be able to feed them and to water them. 644 00:39:16,240 --> 00:39:19,750 If you can ensure and protect your food supply 645 00:39:19,750 --> 00:39:22,300 and your water supply for all of your people 646 00:39:22,300 --> 00:39:25,330 then you can start to build a large civilization 647 00:39:26,740 --> 00:39:28,800 Narrator: With key resources secured, 648 00:39:28,800 --> 00:39:32,470 the pharaoh's oversaw a long period of stability. 649 00:39:32,470 --> 00:39:35,660 These powerful leaders were able to bring prosperity 650 00:39:35,660 --> 00:39:36,490 to their people. 651 00:39:39,902 --> 00:39:44,152 (Gunther speaks foreign language) 652 00:39:48,380 --> 00:39:50,900 Narrator: It wasn't just Egypt that flourished. 653 00:39:50,900 --> 00:39:53,550 Other civilizations arose between the latitudes 654 00:39:53,550 --> 00:39:55,730 of 20 and 40 degrees North. 655 00:39:57,470 --> 00:39:59,420 In Mesopotamia and Persia, 656 00:40:00,960 --> 00:40:02,050 in Northern India, 657 00:40:03,260 --> 00:40:04,200 in Karakorum, 658 00:40:05,830 --> 00:40:06,660 in China, 659 00:40:08,560 --> 00:40:10,800 in Mexico and Peru, 660 00:40:10,800 --> 00:40:12,520 and in the Mediterranean, 661 00:40:12,520 --> 00:40:17,520 the Mycenaeans, Minoans, Thracians and Etruscans. 662 00:40:18,550 --> 00:40:20,930 All these cultures had similar climates. 663 00:40:21,891 --> 00:40:25,471 (triumphant music) 664 00:40:25,470 --> 00:40:28,240 The kingdom of Katna in modern day Syria 665 00:40:28,240 --> 00:40:30,680 also blossomed during this period. 666 00:40:30,680 --> 00:40:33,140 And established itself as one of the ancient world's 667 00:40:33,140 --> 00:40:35,410 most important economic centers. 668 00:40:37,610 --> 00:40:41,030 It controlled the major trade routes connecting North Africa 669 00:40:41,030 --> 00:40:42,140 and the Middle East. 670 00:40:45,740 --> 00:40:48,460 Bronze Age cultures had something else in common. 671 00:40:50,340 --> 00:40:52,960 Again, it was related to the climate. 672 00:40:52,960 --> 00:40:53,940 Sun worship. 673 00:40:55,870 --> 00:40:57,990 Egyptians venerated the sun god. 674 00:40:58,890 --> 00:41:02,330 In Southern England, the stone circles of Stonehenge 675 00:41:02,330 --> 00:41:04,870 marked the summer and winter solstices 676 00:41:04,870 --> 00:41:07,330 and may have been associated with sun worship. 677 00:41:10,470 --> 00:41:12,730 This structure in the German town of Goseck 678 00:41:12,730 --> 00:41:14,260 is a solar observatory. 679 00:41:18,100 --> 00:41:21,050 This sky disc found in nearby Nebra 680 00:41:21,050 --> 00:41:23,390 is thought to be an astronomical instrument. 681 00:41:26,430 --> 00:41:29,100 Many Bronze Age societies revered the sun 682 00:41:29,100 --> 00:41:30,470 as the giver of life. 683 00:41:34,660 --> 00:41:37,790 2000 years later, all this changed 684 00:41:37,790 --> 00:41:40,870 as the entire Mediterranean region entered a period 685 00:41:40,870 --> 00:41:44,000 that is sometimes called the Dark Ages of antiquity. 686 00:41:45,944 --> 00:41:46,784 (fire whooshing) 687 00:41:46,777 --> 00:41:50,487 From about 1200 BC, civilizations collapsed 688 00:41:50,490 --> 00:41:52,350 one after the other. 689 00:41:52,350 --> 00:41:54,650 Sources refer to seafaring people 690 00:41:54,650 --> 00:41:56,730 who launched raids around the Aegean. 691 00:41:58,510 --> 00:42:00,270 Little is known about them, 692 00:42:00,270 --> 00:42:02,590 only that they always attacked from the sea. 693 00:42:05,461 --> 00:42:06,461 (raiders screaming) 694 00:42:06,460 --> 00:42:08,850 They ransacked towns and cities. 695 00:42:08,850 --> 00:42:12,220 Leaving a trail of destruction wherever they went. 696 00:42:12,220 --> 00:42:14,730 From Greece to Gaza, no one was safe. 697 00:42:15,800 --> 00:42:17,310 Their raids marked the end 698 00:42:17,310 --> 00:42:20,490 of the Mediterranean civilizations of the Bronze Age. 699 00:42:21,868 --> 00:42:24,538 (fire roaring) 700 00:42:27,600 --> 00:42:29,420 Researchers are still investigating 701 00:42:29,420 --> 00:42:32,220 the reasons behind the collapse of these kingdoms. 702 00:42:36,130 --> 00:42:39,960 They suspect that climate change may have played a role. 703 00:42:39,964 --> 00:42:42,964 (foreboding music) 704 00:42:45,240 --> 00:42:48,350 But one of the reasons that these are called the Dark Ages 705 00:42:48,350 --> 00:42:50,330 is that there are so few written records 706 00:42:50,330 --> 00:42:51,770 dating from this time. 707 00:42:56,420 --> 00:42:59,160 Paleoclimatologist Dominik Fleitmann 708 00:42:59,160 --> 00:43:02,870 hopes to shed light on this period using geological data 709 00:43:02,870 --> 00:43:05,330 from the (indistinct) cave in Southern Turkey. 710 00:43:07,740 --> 00:43:10,830 People have been visiting the cave for thousands of years 711 00:43:10,830 --> 00:43:14,130 because it provides not only shelter, but also water. 712 00:43:16,710 --> 00:43:19,310 Large pools were built in ancient times 713 00:43:19,310 --> 00:43:22,100 to collect the rain water that seeps into the cave. 714 00:43:26,330 --> 00:43:27,880 Deeper inside the cave, 715 00:43:27,880 --> 00:43:31,150 this water has created a fascinating climate record. 716 00:43:31,150 --> 00:43:33,650 which Fleitmann is researching. 717 00:43:33,647 --> 00:43:36,477 (boots creaking) 718 00:43:40,320 --> 00:43:43,250 The cave contains huge rock formations, 719 00:43:43,250 --> 00:43:45,930 including stalagmites up to 20 meters tall. 720 00:43:50,490 --> 00:43:52,400 Most are millions of years old. 721 00:43:53,330 --> 00:43:55,590 A walk in this cavern is also a journey 722 00:43:55,590 --> 00:43:57,590 through the area's climatic history. 723 00:44:00,100 --> 00:44:04,350 (Dominik speaks foreign language) 724 00:44:19,598 --> 00:44:21,608 (foreboding music) 725 00:44:21,610 --> 00:44:23,730 Narrator: The problem is that he needs to find 726 00:44:23,730 --> 00:44:24,980 just the right sample 727 00:44:24,980 --> 00:44:26,630 from among all these stalagmites. 728 00:44:30,530 --> 00:44:32,480 Many of these ancient formations 729 00:44:32,480 --> 00:44:34,970 stopped growing at the end of the Bronze Age 730 00:44:34,970 --> 00:44:37,080 when water stopped entering the cave. 731 00:44:40,150 --> 00:44:43,740 Stalactites and stalagmites need a constant supply of water 732 00:44:43,740 --> 00:44:45,850 if they are to grow. 733 00:44:45,847 --> 00:44:48,557 (water dripping) 734 00:44:48,560 --> 00:44:50,170 They're formed by rain water 735 00:44:50,170 --> 00:44:53,410 seeping through soil and dripping off rocks. 736 00:44:53,410 --> 00:44:56,720 The water leaves behind deposits of calcium carbonate 737 00:44:56,720 --> 00:44:58,070 which accumulate over time. 738 00:45:02,520 --> 00:45:04,250 These fragile structures 739 00:45:04,250 --> 00:45:07,040 allow researchers to analyze rainfall patterns 740 00:45:07,040 --> 00:45:08,800 over millennia. 741 00:45:08,800 --> 00:45:10,870 The samples from (indistinct) cave 742 00:45:10,870 --> 00:45:13,260 indicate that the climate changed abruptly 743 00:45:13,260 --> 00:45:14,620 during the Bronze Age. 744 00:45:16,886 --> 00:45:21,136 (Dominik speaks foreign language) 745 00:45:35,450 --> 00:45:37,430 Narrator: This increase in dust layers 746 00:45:37,430 --> 00:45:39,440 shows that during the late Bronze Age, 747 00:45:39,440 --> 00:45:41,740 the climate became dryer. 748 00:45:41,740 --> 00:45:45,100 This is confirmed by the rate of which the stalagmites grew 749 00:45:45,104 --> 00:45:48,194 which slowed noticeably during the period. 750 00:45:51,850 --> 00:45:54,400 In contrast to preceding centuries, 751 00:45:54,400 --> 00:45:58,200 almost no new layers of limestone were added. 752 00:45:58,200 --> 00:46:00,270 This suggests a decrease in rainfall 753 00:46:00,270 --> 00:46:04,530 around the Mediterranean from about 1200 BC. 754 00:46:04,530 --> 00:46:06,830 The whole region was in the grip of drought. 755 00:46:08,536 --> 00:46:12,786 (Dominik speaks foreign language) 756 00:46:17,630 --> 00:46:19,760 Narrator: A recipe for disaster indeed, 757 00:46:19,760 --> 00:46:21,330 as recurring droughts affected 758 00:46:21,330 --> 00:46:23,460 the entire Mediterranean region. 759 00:46:25,042 --> 00:46:27,542 (bell tolls) 760 00:46:30,160 --> 00:46:32,610 Soon soils were depleted. 761 00:46:32,610 --> 00:46:34,570 Fields could no longer be tilled. 762 00:46:39,450 --> 00:46:42,930 The mysterious seafarers who raided kingdom after kingdom 763 00:46:42,930 --> 00:46:44,990 were actually climate refugees. 764 00:46:49,440 --> 00:46:52,730 Huge numbers of migrants overran Egypt. 765 00:46:52,730 --> 00:46:55,650 Word had spread that it was rich in resources 766 00:46:55,650 --> 00:46:58,250 and that the pharaohs granaries were well stocked. 767 00:46:59,298 --> 00:47:00,898 (crowd shouting) 768 00:47:00,900 --> 00:47:04,070 Ramesses the third eventually won a resounding victory 769 00:47:04,070 --> 00:47:05,530 over the raiders. 770 00:47:05,531 --> 00:47:08,361 (crowds shouting) 771 00:47:09,310 --> 00:47:11,640 But their invasion of Egypt was the beginning 772 00:47:11,640 --> 00:47:14,020 of a prolonged gradual decline. 773 00:47:16,210 --> 00:47:19,260 (mournful singing) 774 00:47:19,260 --> 00:47:20,960 -: So the old kingdom ruled 775 00:47:20,960 --> 00:47:22,860 for hundreds and hundreds of years. 776 00:47:22,860 --> 00:47:26,630 And then a cold snap produced drought 777 00:47:26,630 --> 00:47:27,880 across the Middle East. 778 00:47:27,880 --> 00:47:29,710 The key problem with drought 779 00:47:29,710 --> 00:47:33,850 is it means that your food supply stops. 780 00:47:33,850 --> 00:47:37,010 If you don't have enough food, you can't feed people. 781 00:47:37,010 --> 00:47:39,500 Those people then either migrate to other places 782 00:47:39,500 --> 00:47:40,890 where there is food, 783 00:47:40,890 --> 00:47:43,760 or they actually start trying to produce food themselves. 784 00:47:43,760 --> 00:47:46,410 So what you have is every layer of government 785 00:47:46,410 --> 00:47:49,990 starts to collapse because you can't feed people 786 00:47:49,990 --> 00:47:51,800 that are trying to run the country. 787 00:47:51,800 --> 00:47:55,100 And you see that the old kingdom collapses. 788 00:47:55,100 --> 00:47:57,590 Egypt shows us the power of climate. 789 00:47:58,520 --> 00:48:02,050 Narrator: So kingdoms fell because of a climate anomaly. 790 00:48:02,054 --> 00:48:04,894 (dramatic music) 791 00:48:06,480 --> 00:48:08,680 Rainfall drops substantially, 792 00:48:08,680 --> 00:48:10,620 and temperatures were the lowest they'd been 793 00:48:10,620 --> 00:48:12,390 since the end of the ice age. 794 00:48:14,470 --> 00:48:17,180 It wasn't until about 300 BC 795 00:48:17,180 --> 00:48:18,470 that the earth's alignment 796 00:48:18,470 --> 00:48:20,910 again made the climate more favorable, 797 00:48:20,910 --> 00:48:23,820 with milder temperatures and regular rainfall. 798 00:48:24,758 --> 00:48:27,428 (wind blowing) 799 00:48:28,680 --> 00:48:29,850 In the mountains, 800 00:48:29,850 --> 00:48:31,180 glaciers receded. 801 00:48:32,170 --> 00:48:35,340 The balance of nature was restored in the Mediterranean 802 00:48:35,340 --> 00:48:36,270 and beyond. 803 00:48:38,848 --> 00:48:41,428 (thunder roars) 804 00:48:41,430 --> 00:48:44,400 The changes brought an end to the climate crisis 805 00:48:44,400 --> 00:48:47,960 and much needed relief to ecosystems all over the world, 806 00:48:47,960 --> 00:48:49,820 including Africa. 807 00:48:49,815 --> 00:48:52,615 (rain pours) 808 00:48:52,620 --> 00:48:55,850 Abundant rainfall replenished groundwater levels. 809 00:48:58,220 --> 00:49:00,580 Soils became fertile again 810 00:49:00,580 --> 00:49:02,790 and crops thrived in Northern Africa. 811 00:49:08,360 --> 00:49:11,500 Emmer, the most sought after export of the time 812 00:49:11,500 --> 00:49:13,490 grew as far as the eye could see. 813 00:49:21,348 --> 00:49:25,428 (Frank speaks foreign language) 814 00:49:32,830 --> 00:49:33,710 Narrator: This abundance 815 00:49:33,710 --> 00:49:36,660 attracted the attention of an emerging power, 816 00:49:36,660 --> 00:49:39,920 which obtained access to Africa's granaries by force. 817 00:49:42,470 --> 00:49:46,490 It subjugated its archenemy Carthage in the Punic Wars 818 00:49:46,490 --> 00:49:49,380 and secured its food supply for centuries to come. 819 00:49:55,520 --> 00:49:58,890 The rising imperial power was Rome. 820 00:49:58,890 --> 00:50:00,550 During its golden age, 821 00:50:00,550 --> 00:50:04,000 more than 800,000 people lived in it's busting capitol 822 00:50:04,000 --> 00:50:05,120 on the river Tiber. 823 00:50:06,225 --> 00:50:10,585 (people having conversations) 824 00:50:10,588 --> 00:50:12,708 Famous for both its efficient administration 825 00:50:12,710 --> 00:50:14,750 and its extravagant lifestyle, 826 00:50:14,750 --> 00:50:18,010 the Roman Empire outshone all that had come before it. 827 00:50:20,847 --> 00:50:25,007 (Gunther speaks foreign language) 828 00:50:43,921 --> 00:50:45,431 (crowd cheers) 829 00:50:45,430 --> 00:50:48,100 Narrator: At home, Rome kept its people content 830 00:50:48,100 --> 00:50:49,780 with bread and circuses. 831 00:50:52,260 --> 00:50:54,640 Abroad, it expanded its empire. 832 00:50:56,520 --> 00:50:58,760 The climate favored Rome. 833 00:51:00,390 --> 00:51:03,220 (dramatic music)