1 00:00:03,981 --> 00:00:04,932 Announcer: (singing) mtv. 2 00:00:04,967 --> 00:00:08,992 Narrator: In the 1960s, for the first time in history, 3 00:00:09,027 --> 00:00:12,432 Manned space flight becomes a reality. 4 00:00:12,507 --> 00:00:15,232 It inspires people around the world 5 00:00:15,267 --> 00:00:20,512 And forever changes the way we view our planet. 6 00:00:20,547 --> 00:00:23,432 We get a startling new perspective. 7 00:00:23,507 --> 00:00:28,519 Boundaries that separate countries disappear, 8 00:00:28,594 --> 00:00:32,839 And the air that surrounds us flows uninterrupted over land 9 00:00:32,914 --> 00:00:35,799 And sea. 10 00:00:35,874 --> 00:00:39,712 Earth has an invisible feature that sets it apart from almost 11 00:00:39,747 --> 00:00:42,312 All other heavenly bodies-- 12 00:00:42,387 --> 00:00:46,912 An atmosphere that makes life possible. 13 00:00:46,987 --> 00:00:52,952 It's a mix of gases, mostly nitrogen, then oxygen, argon, 14 00:00:53,027 --> 00:00:57,792 Co2, methane, and water vapor, a balance 15 00:00:57,827 --> 00:01:03,392 That's existed for longer than we're able to calculate. 16 00:01:03,427 --> 00:01:06,679 And then humans arrive on the scene. 17 00:01:06,754 --> 00:01:12,192 Full of curiosity and hard-wired ingenuity, our ancestors 18 00:01:12,201 --> 00:01:14,472 Discover fire. 19 00:01:14,547 --> 00:01:17,912 Fire creates new sources of food and allows 20 00:01:17,987 --> 00:01:21,752 Us to settle the northern regions of our planet. 21 00:01:21,827 --> 00:01:24,752 At this moment, humans gain the ability 22 00:01:24,787 --> 00:01:28,192 To alter the air in our atmosphere, 23 00:01:28,227 --> 00:01:31,632 And we've never stopped. 24 00:01:31,667 --> 00:01:35,072 This is the era some call the age of humans, 25 00:01:35,107 --> 00:01:38,072 A period in earth's history where people are 26 00:01:38,147 --> 00:01:44,352 The dominant force, reshaping earth, sea, and sky, 27 00:01:44,387 --> 00:01:46,512 The air that gives us life. 28 00:01:46,521 --> 00:01:49,919 [majestic music] 29 00:02:01,481 --> 00:02:05,272 Humanity's need for energy is what has most affected 30 00:02:05,347 --> 00:02:07,552 The air on planet earth. 31 00:02:07,627 --> 00:02:11,632 Pollution and chemical changes caused by our need for fuel 32 00:02:11,667 --> 00:02:15,072 Are the biggest causes of climate change. 33 00:02:15,107 --> 00:02:18,672 This is iceland, a country that's witnessing the effects 34 00:02:18,707 --> 00:02:21,792 Of a warming planet firsthand. 35 00:02:21,827 --> 00:02:27,792 In the summer of 2019, they mark the death of a glacier. 36 00:02:27,827 --> 00:02:31,792 Within just 130 years, ice that was once more 37 00:02:31,827 --> 00:02:35,792 Than 400 feet thick melted. 38 00:02:35,827 --> 00:02:39,872 It's a fate that may await many more glaciers in the future. 39 00:02:39,907 --> 00:02:42,072 The world's ice sheets are losing 40 00:02:42,147 --> 00:02:47,472 An astonishing 125 billion tons of mass every year. 41 00:02:47,507 --> 00:02:50,679 [somber music] 42 00:02:52,507 --> 00:02:55,479 At the goddard space flight center in washington, dc, 43 00:02:55,554 --> 00:02:58,592 Nasa scientists are monitoring the glaciers 44 00:02:58,667 --> 00:03:01,472 And can tell exactly where the mountains of ice 45 00:03:01,481 --> 00:03:04,912 Are most affected. 46 00:03:04,947 --> 00:03:07,232 What we see here are these bubbles popping 47 00:03:07,267 --> 00:03:09,552 Up as we move across the globe. 48 00:03:09,627 --> 00:03:14,432 And these bubbles are indicating each individual glacier 49 00:03:14,467 --> 00:03:18,032 From the himalaya through alaska, 50 00:03:18,107 --> 00:03:21,639 And then we're going to move to south america. 51 00:03:21,714 --> 00:03:24,072 And underlying these glaciers-- we're 52 00:03:24,147 --> 00:03:26,839 Going to show a map here-- in these particular regions, 53 00:03:26,914 --> 00:03:28,512 We're getting a lot of blue. 54 00:03:28,547 --> 00:03:30,679 And that blue color is indicating 55 00:03:30,754 --> 00:03:32,359 That these glaciers are melting, and 56 00:03:32,434 --> 00:03:34,632 They're losing mass over time. 57 00:03:34,707 --> 00:03:39,592 And as we move to alaska, we'll see an even darker purple. 58 00:03:39,667 --> 00:03:41,912 And that purple is really indicating 59 00:03:41,987 --> 00:03:44,039 A strong amount of mass loss. 60 00:03:46,594 --> 00:03:48,679 Narrator: Glaciers are like thermometers 61 00:03:48,754 --> 00:03:50,999 That indicate the health of the world's climate. 62 00:03:56,307 --> 00:03:59,199 Since 1850, they've been steadily receding. 63 00:04:02,521 --> 00:04:07,152 In iceland alone, 28 out of 34 glaciers 64 00:04:07,187 --> 00:04:10,272 Have shrunk by thousands of feet. 65 00:04:10,307 --> 00:04:13,432 Some people believe this is due to natural causes, 66 00:04:13,507 --> 00:04:17,079 Such as volcanic activity, which is widespread in iceland. 67 00:04:24,547 --> 00:04:27,392 The thrihnukagigur volcano, for example, 68 00:04:27,427 --> 00:04:30,472 Has been dormant for 4,000 years. 69 00:04:30,547 --> 00:04:33,072 It provides a unique glimpse into a magma 70 00:04:33,107 --> 00:04:35,439 Chamber almost 400 feet deep. 71 00:04:41,267 --> 00:04:44,352 Despite the impressive dimensions of volcanoes, 72 00:04:44,361 --> 00:04:47,312 Their contribution to worldwide co2 emissions 73 00:04:47,347 --> 00:04:51,632 Is small, responsible for only 1% of greenhouse 74 00:04:51,667 --> 00:04:53,199 Gases in the atmosphere. 75 00:04:56,841 --> 00:05:00,432 Yet today, we have more co2 in our air 76 00:05:00,467 --> 00:05:02,759 Than in the last 3 million years. 77 00:05:05,507 --> 00:05:07,392 [birds chirping] 78 00:05:07,467 --> 00:05:09,952 [water rushing] 79 00:05:09,987 --> 00:05:12,432 Many of us think of modern industry 80 00:05:12,467 --> 00:05:15,072 As the main cause of changes to our air, 81 00:05:15,107 --> 00:05:20,112 And it is by far the biggest factor. 82 00:05:20,147 --> 00:05:22,839 But humans were changing the air long 83 00:05:22,914 --> 00:05:24,752 Before the existence of factories 84 00:05:24,827 --> 00:05:28,432 And the combustion engine. 85 00:05:28,467 --> 00:05:31,799 For more than 5,000 years, the chinese have 86 00:05:31,874 --> 00:05:36,592 Worked their land to grow rice. 87 00:05:36,627 --> 00:05:40,679 It's one of the most important agricultural crops in the world 88 00:05:40,754 --> 00:05:43,479 And the main source of nutrition for half 89 00:05:43,554 --> 00:05:46,359 The population of the planet. 90 00:05:46,434 --> 00:05:48,512 China is its biggest producer. 91 00:05:48,521 --> 00:05:51,399 [majestic music] 92 00:05:52,827 --> 00:05:55,392 Rice can be farmed in different ways. 93 00:05:55,427 --> 00:05:57,872 Wet cultivation is the most common, 94 00:05:57,947 --> 00:06:00,839 Done by flooding paddy fields. 95 00:06:00,914 --> 00:06:04,432 Given the right conditions, heat, and humidity, 96 00:06:04,467 --> 00:06:08,752 This method can yield three harvests a year, 97 00:06:08,787 --> 00:06:11,479 But it takes a tremendous amount of water. 98 00:06:17,187 --> 00:06:22,832 Each pound of rice takes about 500 gallons of water to grow. 99 00:06:22,867 --> 00:06:26,192 The upside is increased food production. 100 00:06:26,227 --> 00:06:30,992 The downside is that wet farming produces gases. 101 00:06:31,027 --> 00:06:34,832 Permanent flooding of the soil creates an environment almost 102 00:06:34,867 --> 00:06:38,632 Free of oxygen, feeding anaerobic, single-celled 103 00:06:38,707 --> 00:06:42,512 Organisms that create methane. 104 00:06:42,547 --> 00:06:46,832 Wet rice farming is responsible for 17% of all 105 00:06:46,841 --> 00:06:49,912 The methane in our atmosphere. 106 00:06:49,987 --> 00:06:52,792 Though carbon dioxide is considered the most destructive 107 00:06:52,867 --> 00:06:58,272 Man-made greenhouse gas, methane is more potent because of how 108 00:06:58,307 --> 00:07:01,159 Effectively it absorbs heat. 109 00:07:01,234 --> 00:07:04,432 In fact, its effect on global warming 110 00:07:04,467 --> 00:07:08,679 Is 25 times greater than co2. 111 00:07:12,227 --> 00:07:15,439 [tense music] 112 00:07:17,627 --> 00:07:20,832 As human civilizations evolve around the world, 113 00:07:20,841 --> 00:07:24,199 They create new ways to impact the atmosphere. 114 00:07:24,274 --> 00:07:27,792 2,000 years ago in ancient rome, glass production 115 00:07:27,801 --> 00:07:30,152 Is a flourishing industry, requiring 116 00:07:30,227 --> 00:07:32,672 Huge quantities of firewood. 117 00:07:32,707 --> 00:07:36,592 The ovens churn out enough smoke to create what the locals call 118 00:07:36,627 --> 00:07:40,792 Gravioris caeli, latin for the overcast sky that 119 00:07:40,867 --> 00:07:42,359 Shrouds the city. 120 00:07:42,434 --> 00:07:45,112 Eventually, the emperor expels the glassblowers 121 00:07:45,187 --> 00:07:46,839 From the capital. 122 00:07:46,914 --> 00:07:50,912 By then, the forests around rome have been largely chopped down, 123 00:07:50,947 --> 00:07:53,632 And a new fuel is on the horizon. 124 00:07:53,641 --> 00:07:58,112 Coal is created when organic material like trees and plants 125 00:07:58,147 --> 00:08:00,992 Decompose at the bottom of lakes or swamps 126 00:08:01,027 --> 00:08:04,432 In the absence of air. 127 00:08:04,467 --> 00:08:07,432 Geological processes compress the material, 128 00:08:07,507 --> 00:08:09,952 And, over millions of years, it becomes 129 00:08:09,987 --> 00:08:12,999 Buried by layers of earth or marine sediment, 130 00:08:13,074 --> 00:08:14,759 Eventually becoming coal. 131 00:08:17,507 --> 00:08:22,272 The first people to use coal are the chinese about 5,000 years 132 00:08:22,307 --> 00:08:24,472 Ago, and then the rest of the world 133 00:08:24,547 --> 00:08:28,512 Discovers it, mostly for use in homes. 134 00:08:28,547 --> 00:08:33,239 By the mid-1500s in europe, it's first mined for industrial use. 135 00:08:35,947 --> 00:08:38,512 Extracting coal may be hard work, 136 00:08:38,547 --> 00:08:41,952 But it becomes highly lucrative. 137 00:08:41,961 --> 00:08:44,912 Coal is much denser than wood. 138 00:08:44,947 --> 00:08:48,632 It burns longer, hotter, and more evenly, 139 00:08:48,707 --> 00:08:53,432 Although the ash and soot it creates are much dirtier. 140 00:08:53,507 --> 00:08:57,632 As coal becomes popular, tens of thousands of people 141 00:08:57,667 --> 00:09:00,632 Earn a living from coal mining, at first, 142 00:09:00,707 --> 00:09:01,839 Using primitive methods. 143 00:09:04,787 --> 00:09:07,552 Gradually, surface coal extraction 144 00:09:07,587 --> 00:09:10,272 Gives way to mining at greater depths, 145 00:09:10,307 --> 00:09:14,239 Since generally, the deeper the seam, the better the coal. 146 00:09:17,827 --> 00:09:19,959 [speaking german] 147 00:09:20,034 --> 00:09:23,232 Interpreter 1: To smelt ore, which usually is won by mining, 148 00:09:23,267 --> 00:09:25,552 You need extremely high temperatures, which 149 00:09:25,587 --> 00:09:27,639 Can only be achieved by burning coal, 150 00:09:27,714 --> 00:09:30,199 Which has to be mined, too. 151 00:09:30,274 --> 00:09:32,032 That's why coal mining, which started 152 00:09:32,067 --> 00:09:34,992 In the 12th and 13th centuries, until it was carried out 153 00:09:35,001 --> 00:09:37,872 On a grand scale at the end of the 18th century, 154 00:09:37,947 --> 00:09:40,272 Is of immeasurable importance for the development 155 00:09:40,307 --> 00:09:42,432 Of the age of humans. 156 00:09:42,507 --> 00:09:45,232 That's when the world started to change in earnest. 157 00:09:45,267 --> 00:09:47,279 [speaking german] 158 00:09:49,427 --> 00:09:50,992 Narrator: Lignite is a rock that's 159 00:09:51,027 --> 00:09:53,392 Also known as brown coal. 160 00:09:53,427 --> 00:09:56,792 It's almost exclusively extracted in pit mines 161 00:09:56,867 --> 00:10:01,072 And is performed by some of the biggest machines in the world. 162 00:10:01,107 --> 00:10:04,632 90% of brown coal is used in power stations 163 00:10:04,707 --> 00:10:06,832 To create electricity. 164 00:10:06,867 --> 00:10:11,159 Worldwide, humans extract approximately 8 million tons 165 00:10:11,234 --> 00:10:14,679 Of coal and lignite each year. 166 00:10:14,754 --> 00:10:18,112 These resources will last for several more centuries, 167 00:10:18,147 --> 00:10:20,752 But they come with a cost. 168 00:10:20,787 --> 00:10:23,552 Mining doesn't just scar the earth. 169 00:10:23,587 --> 00:10:27,432 Emissions from burning coal have already been changing the air 170 00:10:27,507 --> 00:10:28,839 For well over a century. 171 00:10:31,787 --> 00:10:33,712 [whimsical music] 172 00:10:33,747 --> 00:10:35,632 It's 1870. 173 00:10:35,667 --> 00:10:40,672 London is the biggest city in the world, and it runs on coal. 174 00:10:40,681 --> 00:10:43,472 3 and 1/2 million fires burn day and night 175 00:10:43,481 --> 00:10:46,272 In factories and private homes. 176 00:10:46,307 --> 00:10:48,832 For families that heat their houses with coal, 177 00:10:48,841 --> 00:10:51,312 Their chimneys need cleaning. 178 00:10:51,321 --> 00:10:52,912 We've come to sweep your chimney, sir. 179 00:10:52,947 --> 00:10:55,472 Man: In you come. 180 00:10:55,507 --> 00:10:57,952 Narrator: Accumulations of soot are dangerous. 181 00:10:57,987 --> 00:11:00,912 They can burn and start accidental fires. 182 00:11:00,947 --> 00:11:04,192 As chimneys are too small for adults to climb through, 183 00:11:04,227 --> 00:11:08,192 Male children known as chimney boys are put to work. 184 00:11:08,201 --> 00:11:10,072 Chimney sweep: Get in there, and up you go. 185 00:11:10,147 --> 00:11:12,832 Narrator: Usually, they're orphans or children who have 186 00:11:12,867 --> 00:11:15,632 Been sold by their parents. 187 00:11:15,667 --> 00:11:18,432 No attention is paid to the soot these boys 188 00:11:18,467 --> 00:11:20,472 Breathe into their lungs. 189 00:11:20,547 --> 00:11:23,072 Many suffer serious health problems 190 00:11:23,107 --> 00:11:25,952 And die at an early age. 191 00:11:25,987 --> 00:11:28,592 The exploitation of chimney boys is finally 192 00:11:28,667 --> 00:11:31,952 Outlawed at the end of the 19th century, 193 00:11:31,987 --> 00:11:34,639 But the tragedies don't end there. 194 00:11:37,827 --> 00:11:39,712 [ominous music] 195 00:11:39,787 --> 00:11:42,512 It's 1952 in london, and the air is 196 00:11:42,547 --> 00:11:45,112 Choked in soot from coal fires. 197 00:11:45,187 --> 00:11:48,592 A dangerous weather anomaly forms when pollution joins 198 00:11:48,667 --> 00:11:51,479 With fog to form a noxious blanket that covers 199 00:11:51,554 --> 00:11:53,472 The city for several days. 200 00:11:53,507 --> 00:11:56,112 It becomes known as the great smog, 201 00:11:56,147 --> 00:11:59,439 Causing respiratory infections and thousands of deaths. 202 00:12:03,641 --> 00:12:06,112 Today, coal heating has been banned 203 00:12:06,147 --> 00:12:08,272 In many major cities like london, 204 00:12:08,307 --> 00:12:10,559 But it's still widely used around the world. 205 00:12:13,667 --> 00:12:17,232 8 billion tons of coal are still mined every year 206 00:12:17,307 --> 00:12:21,232 Around the world, primarily in china, followed 207 00:12:21,307 --> 00:12:28,032 By india and the united states. 208 00:12:28,067 --> 00:12:31,159 Coal-fired power stations produce about 40% 209 00:12:31,234 --> 00:12:33,552 Of the world's electricity, supplying more 210 00:12:33,587 --> 00:12:35,952 Than 12,000 power stations. 211 00:12:35,987 --> 00:12:39,159 One of the most serious problems of burning coal 212 00:12:39,234 --> 00:12:42,432 Is that it produces carbon dioxide, the most 213 00:12:42,467 --> 00:12:45,792 Dangerous and prevalent of the greenhouse gases 214 00:12:45,801 --> 00:12:49,272 And one of the main causes of global warming. 215 00:12:49,347 --> 00:12:51,312 The scale of the problem is the hardest 216 00:12:51,321 --> 00:12:53,072 Thing for people to grasp. 217 00:12:53,107 --> 00:12:56,952 At the moment, we're putting 50 gigatons of co2 218 00:12:57,027 --> 00:12:59,952 Into the atmosphere every year. 219 00:12:59,987 --> 00:13:03,472 Now, what would it take to get just 1/10 of that 220 00:13:03,507 --> 00:13:06,632 Out, say, five gigatons out of the atmosphere? 221 00:13:06,707 --> 00:13:09,792 To do that, we'd have to plant the lower 48 states of the usa 222 00:13:09,827 --> 00:13:13,799 In forest, the whole thing, and have it growing vigorously 223 00:13:13,874 --> 00:13:15,799 For a century to get, on average, 224 00:13:15,874 --> 00:13:18,512 Around five gigatons of co2 out of the atmosphere 225 00:13:18,547 --> 00:13:20,192 By planting trees. 226 00:13:20,201 --> 00:13:22,632 So you can see the scalability problem, which, it's just-- 227 00:13:22,707 --> 00:13:23,632 It is immense. 228 00:13:23,641 --> 00:13:25,592 [peaceful music] 229 00:13:25,667 --> 00:13:27,839 [water rushing] 230 00:13:29,507 --> 00:13:32,312 Narrator: Around the world, all kinds of efforts 231 00:13:32,387 --> 00:13:36,352 Are underway to remove carbon dioxide from the air. 232 00:13:36,387 --> 00:13:42,512 One pilot project in iceland is turning co2 to stone, drawing 233 00:13:42,547 --> 00:13:45,472 Inspiration from nature itself. 234 00:13:45,507 --> 00:13:48,432 Under certain conditions, co2 becomes 235 00:13:48,467 --> 00:13:51,392 A mineral called carbonate. 236 00:13:51,467 --> 00:13:55,632 As a natural process, this takes thousands of years. 237 00:13:55,667 --> 00:13:59,072 But this group has created technology that imitates 238 00:13:59,107 --> 00:14:01,712 And accelerates natural processes 239 00:14:01,787 --> 00:14:07,552 And literally turns co2 into stone in less than two years. 240 00:14:07,627 --> 00:14:09,912 These rocks, called basalt, they 241 00:14:09,987 --> 00:14:14,272 Contain high amount of calcium, magnesium, and iron. 242 00:14:14,307 --> 00:14:19,712 And when water, which we capture co2 in, 243 00:14:19,747 --> 00:14:23,392 Comes into contact with this rock formation, 244 00:14:23,427 --> 00:14:27,432 It actually dissolves, releasing the calcium, magnesium, 245 00:14:27,507 --> 00:14:32,432 And iron into the water face, where these chemicals can meet 246 00:14:32,467 --> 00:14:36,472 Up with the dissolved co2, and a new mineral 247 00:14:36,547 --> 00:14:39,392 Is formed, called carbonate. 248 00:14:39,427 --> 00:14:42,592 Narrator: The work here is energy-intensive and therefore 249 00:14:42,667 --> 00:14:45,392 Linked to a geothermal power plant, 250 00:14:45,427 --> 00:14:48,992 Since the process to transform greenhouse gases only 251 00:14:49,027 --> 00:14:52,592 Makes sense if it uses clean energy. 252 00:14:52,627 --> 00:14:56,272 It's promising new technology, but it's not enough. 253 00:14:56,347 --> 00:14:58,679 All around the world, corporations 254 00:14:58,754 --> 00:15:02,472 Can buy the right to emit certain quantities of co2, 255 00:15:02,547 --> 00:15:05,432 A program that has plenty of critics. 256 00:15:05,507 --> 00:15:08,112 In this world, money is what speaks, 257 00:15:08,147 --> 00:15:11,232 And we need to make the polluters pay 258 00:15:11,267 --> 00:15:12,992 For the damage they're doing. 259 00:15:13,027 --> 00:15:16,832 We know that we can extract carbon out of the atmosphere 260 00:15:16,867 --> 00:15:19,272 For a cost of about $100 a ton. 261 00:15:19,347 --> 00:15:21,959 And we know that, in 10 to 20 years, 262 00:15:22,034 --> 00:15:23,959 We'll be doing our utmost to do that, 263 00:15:24,034 --> 00:15:25,959 And we'll be paying that cost. 264 00:15:26,034 --> 00:15:28,672 So how is it that today, we can let people put that pollution 265 00:15:28,707 --> 00:15:32,432 Into the atmosphere for free? 266 00:15:32,467 --> 00:15:34,432 Narrator: Other efforts are also looking 267 00:15:34,467 --> 00:15:40,192 To nature for solutions, but without high-tech processes. 268 00:15:40,227 --> 00:15:44,192 In china, deserts are expanding as forests were cut 269 00:15:44,227 --> 00:15:45,639 Down aggressively over decades. 270 00:15:49,554 --> 00:15:53,152 All that ended in 1978 and was replaced 271 00:15:53,187 --> 00:15:55,679 By an unprecedented reforestation program. 272 00:16:02,361 --> 00:16:05,392 So far, an astonishing 60 billion 273 00:16:05,427 --> 00:16:06,992 Trees have been planted. 274 00:16:07,001 --> 00:16:10,359 [stately music] 275 00:16:17,787 --> 00:16:20,359 Workers place brush in the sand to form 276 00:16:20,434 --> 00:16:22,472 Windbreaks that prevent young trees 277 00:16:22,547 --> 00:16:24,159 From being buried under sand. 278 00:16:27,187 --> 00:16:30,992 The goal is to recreate a forest as big as germany 279 00:16:31,027 --> 00:16:34,632 By the year 2050, forming a green wall 280 00:16:34,707 --> 00:16:38,632 To hold back the gobi desert. 281 00:16:38,707 --> 00:16:42,839 The great green wall of china is keeping the sand in place, 282 00:16:42,914 --> 00:16:46,599 And, as the forest grows, it will also help filter co2. 283 00:16:50,467 --> 00:16:53,312 Elsewhere, in milan, Italy, the bosco 284 00:16:53,347 --> 00:16:56,359 Verticale, or vertical forest, is an example 285 00:16:56,434 --> 00:16:58,472 Of green architecture. 286 00:16:58,547 --> 00:17:01,152 Though there aren't enough trees here to filter the air, 287 00:17:01,187 --> 00:17:03,952 They are a stunning reminder of our relationship 288 00:17:03,987 --> 00:17:04,959 To the natural world. 289 00:17:09,001 --> 00:17:11,232 For centuries, humans have wanted 290 00:17:11,267 --> 00:17:14,032 To know what's in our air. 291 00:17:14,067 --> 00:17:17,792 Joseph priestley was an englishman known as the man who 292 00:17:17,801 --> 00:17:21,952 Discovered oxygen. In the 17th century, 293 00:17:21,987 --> 00:17:24,072 He's running experiments to find out 294 00:17:24,147 --> 00:17:29,432 How objects and living things behave in the absence of air. 295 00:17:29,507 --> 00:17:32,272 He discovers that, without air, candles 296 00:17:32,307 --> 00:17:37,592 No longer burn and animals die. 297 00:17:37,667 --> 00:17:41,152 But when he introduces plants into the experiment, 298 00:17:41,161 --> 00:17:45,432 The candle burns and the mouse lives. 299 00:17:45,507 --> 00:17:49,479 He concludes that plants refresh the air, the process we 300 00:17:49,554 --> 00:17:53,479 Know today as photosynthesis. 301 00:17:53,554 --> 00:17:57,632 Photosynthesis occurs when plants, with the help of light, 302 00:17:57,667 --> 00:18:01,312 Water, and carbon dioxide, produce glucose that 303 00:18:01,321 --> 00:18:03,999 Releases oxygen into the air. 304 00:18:05,714 --> 00:18:08,352 These days, co2 is usually talked 305 00:18:08,387 --> 00:18:12,352 About for the harmful role it plays in climate change. 306 00:18:12,387 --> 00:18:15,232 But the gas is critical for life on earth 307 00:18:15,267 --> 00:18:18,072 And essential for plant growth. 308 00:18:18,147 --> 00:18:21,792 In fact, when carbon dioxide levels increase, 309 00:18:21,827 --> 00:18:25,792 Plants actually grow faster, as if being fertilized. 310 00:18:25,827 --> 00:18:30,679 It's a phenomenon known as the co2 fertilization effect, 311 00:18:30,754 --> 00:18:33,359 And in the netherlands, they're putting it to work. 312 00:18:36,387 --> 00:18:40,112 Here, massive greenhouses cover more than 19 313 00:18:40,147 --> 00:18:45,159 Square miles, growing everything from flowers 314 00:18:45,234 --> 00:18:47,872 To fruit and vegetables. 315 00:18:47,907 --> 00:18:51,152 Inside these carefully controlled environments, 316 00:18:51,161 --> 00:18:54,352 Crops can produce 10 times more than what 317 00:18:54,361 --> 00:18:57,639 Farmers get in regular fields. 318 00:18:57,714 --> 00:19:01,912 At this sweet pepper plantation, they use co2 emissions 319 00:19:01,987 --> 00:19:04,912 From nearby factories to accelerate 320 00:19:04,947 --> 00:19:05,959 The growth of their plants. 321 00:19:09,187 --> 00:19:10,719 Roos varekamp: [speaking dutch] 322 00:19:12,187 --> 00:19:13,872 Interpreter 2: All along these hoses, 323 00:19:13,907 --> 00:19:18,832 There are tiny holes through which the co2 may pass out. 324 00:19:18,867 --> 00:19:21,432 It then slowly rises among the plants, 325 00:19:21,507 --> 00:19:23,552 So they have ample time to absorb it. 326 00:19:23,627 --> 00:19:25,599 [speaking dutch] 327 00:19:28,387 --> 00:19:32,199 Narrator: Since plants store and use carbon dioxide, 328 00:19:32,274 --> 00:19:34,959 Trees play a big part in the story of co2. 329 00:19:37,987 --> 00:19:41,592 But here, too, humans are using up natural resources 330 00:19:41,667 --> 00:19:45,159 At an unprecedented rate and, in some cases, 331 00:19:45,234 --> 00:19:48,999 Actually burning them down to use the land. 332 00:19:49,074 --> 00:19:52,912 In the summer of 2019, more than 70,000 fires 333 00:19:52,947 --> 00:19:56,072 Are burning in the amazon basin, destroying more 334 00:19:56,147 --> 00:19:58,792 Than a million acres of forest. 335 00:19:58,867 --> 00:20:02,112 Most of them are intentionally started to make room, not 336 00:20:02,147 --> 00:20:04,432 For people, but for livestock. 337 00:20:04,507 --> 00:20:07,679 [tense music] 338 00:20:09,827 --> 00:20:11,399 [speaking german] 339 00:20:13,161 --> 00:20:15,632 Interpreter 1: If we burn down forests on a large scale, 340 00:20:15,667 --> 00:20:17,072 This not only increases the amount 341 00:20:17,147 --> 00:20:19,152 Of co2 in the atmosphere. 342 00:20:19,187 --> 00:20:20,832 We also destroy the reservoirs where 343 00:20:20,867 --> 00:20:23,752 Carbon dioxide can be stored. 344 00:20:23,827 --> 00:20:27,432 By practicing deforestation, we influence the climate, 345 00:20:27,507 --> 00:20:29,312 And many of our other activities also 346 00:20:29,347 --> 00:20:32,272 Have an effect, both on the biosphere and the geosphere. 347 00:20:32,307 --> 00:20:34,639 [speaking german] 348 00:20:36,227 --> 00:20:37,799 Narrator: Large-scale cattle farming 349 00:20:37,874 --> 00:20:41,072 Is another significant cause of greenhouse gases. 350 00:20:41,107 --> 00:20:44,432 Around the world, about 1 and 1/2 billion cattle 351 00:20:44,507 --> 00:20:46,912 Are raised for food, with devastating 352 00:20:46,947 --> 00:20:49,312 Consequences to the air. 353 00:20:49,347 --> 00:20:52,952 Today, 15% of greenhouse gases originate from 354 00:20:53,027 --> 00:20:55,792 Large-scale livestock farming. 355 00:20:55,827 --> 00:20:58,512 In the australian outback, the animals number 356 00:20:58,547 --> 00:21:01,792 In the tens, sometimes hundreds, of thousands. 357 00:21:01,827 --> 00:21:04,432 Mega ranches like this one help satisfy 358 00:21:04,467 --> 00:21:06,912 The worldwide hunger for beef. 359 00:21:06,947 --> 00:21:10,199 And here, the concern isn't co2. 360 00:21:10,274 --> 00:21:13,159 It's methane. 361 00:21:13,234 --> 00:21:16,592 The digestive tracts of cows emit methane, 362 00:21:16,627 --> 00:21:20,512 Far more than is created on chinese rice paddies. 363 00:21:20,547 --> 00:21:23,392 A single cow produces about as much 364 00:21:23,427 --> 00:21:26,679 Greenhouse gas in one year as a car 365 00:21:26,754 --> 00:21:30,192 Driven more than 11,000 miles. 366 00:21:30,227 --> 00:21:34,032 In fact, if cows were their own country, 367 00:21:34,107 --> 00:21:36,199 They'd be the third largest greenhouse 368 00:21:36,274 --> 00:21:39,632 Gas emitter in the world. 369 00:21:39,667 --> 00:21:43,312 Eating less beef would certainly help clear the air, 370 00:21:43,321 --> 00:21:47,232 But is the human race willing to make that change? 371 00:21:47,267 --> 00:21:48,912 [cows lowing] 372 00:21:48,947 --> 00:21:51,712 [dramatic music] 373 00:21:51,747 --> 00:21:55,312 Since 1950, worldwide consumption of meat 374 00:21:55,347 --> 00:21:58,752 Has increased sixfold, and methane emissions 375 00:21:58,787 --> 00:22:01,152 Have increased as well. 376 00:22:01,187 --> 00:22:03,799 But now that humans realize the cost, 377 00:22:03,874 --> 00:22:05,872 That statistic may be changing. 378 00:22:05,907 --> 00:22:07,632 [speaking german] 379 00:22:07,667 --> 00:22:09,792 Interpreter 1: The less meat we consume, the less we contribute 380 00:22:09,827 --> 00:22:12,272 To climate change, the less gases are emitted 381 00:22:12,307 --> 00:22:15,072 Into the atmosphere, and the less land has to be 382 00:22:15,107 --> 00:22:19,112 Cleared for forage production. 383 00:22:19,187 --> 00:22:21,592 Narrator: Americans are the biggest meat eaters 384 00:22:21,667 --> 00:22:26,832 On the planet, consuming about 265 pounds per person 385 00:22:26,867 --> 00:22:28,512 Each year. 386 00:22:28,521 --> 00:22:30,632 Next in line are south americans, 387 00:22:30,707 --> 00:22:33,632 Europeans, and chinese. 388 00:22:33,667 --> 00:22:35,599 Meat consumption is lowest in africa. 389 00:22:39,394 --> 00:22:42,199 But even in the united states, attitudes 390 00:22:42,274 --> 00:22:44,999 Are changing in the face of global warming, 391 00:22:45,074 --> 00:22:47,912 Especially with young people. 392 00:22:47,987 --> 00:22:51,639 And chefs are happy to oblige. 393 00:22:51,714 --> 00:22:53,632 I think we've gone slightly off the direction 394 00:22:53,641 --> 00:22:55,912 That we should be going in terms of food. 395 00:22:55,987 --> 00:22:58,832 I think that we've done things on an industrial scale 396 00:22:58,867 --> 00:23:01,432 Because that was easier and cheaper, but not necessarily 397 00:23:01,507 --> 00:23:02,879 Better for the environment. 398 00:23:05,987 --> 00:23:07,792 Narrator: Today's meatless burgers are the result 399 00:23:07,801 --> 00:23:11,479 Of many years of research. 400 00:23:11,554 --> 00:23:14,832 This may look like ground beef, but it is in fact 401 00:23:14,867 --> 00:23:17,472 A blend of pure plant products. 402 00:23:17,507 --> 00:23:19,872 Its taste and texture are intended 403 00:23:19,947 --> 00:23:22,592 To resemble meat in every way. 404 00:23:22,627 --> 00:23:25,232 After all, these burgers don't need to convince 405 00:23:25,307 --> 00:23:28,312 Vegetarians, but meat lovers. 406 00:23:28,387 --> 00:23:30,792 And it seems to be working. 407 00:23:30,867 --> 00:23:35,632 Between 2018 and 2019, sales of vegetarian burgers 408 00:23:35,667 --> 00:23:42,519 Alone increased by an incredible 268% in the united states. 409 00:23:42,594 --> 00:23:46,952 If the trend continues, it could be good news for our atmosphere 410 00:23:47,027 --> 00:23:49,232 And life on earth. 411 00:23:49,267 --> 00:23:51,879 [ominous music] 412 00:23:53,747 --> 00:23:56,472 While cattle ranches do their share of damage to the air, 413 00:23:56,547 --> 00:23:58,992 It's fossil fuels that are doing far 414 00:23:59,001 --> 00:24:05,232 More, using coal, natural gas, and, of course, oil. 415 00:24:05,267 --> 00:24:08,679 Each year, more than 4 billion tons of crude oil 416 00:24:08,754 --> 00:24:10,239 Are produced around the world. 417 00:24:16,227 --> 00:24:18,192 [liquid pouring] 418 00:24:18,227 --> 00:24:22,472 In the mid-19th century, an american chemist named benjamin 419 00:24:22,547 --> 00:24:26,032 Silliman distills a substance from crude oil 420 00:24:26,067 --> 00:24:28,672 That will change the world-- 421 00:24:28,707 --> 00:24:29,719 Petroleum. 422 00:24:34,507 --> 00:24:39,072 In fact, the so-called "black gold" is nothing new. 423 00:24:39,147 --> 00:24:42,792 Native american indians from the seneca tribe traded oil 424 00:24:42,867 --> 00:24:46,352 That oozed out of the ground naturally-- 425 00:24:46,387 --> 00:24:48,272 Excellent. 426 00:24:48,307 --> 00:24:50,679 Narrator: --While european settlers used it predominantly 427 00:24:50,754 --> 00:24:53,632 As ointment or grease. 428 00:24:53,667 --> 00:24:57,232 Silliman's discovery attracts investors. 429 00:24:57,267 --> 00:24:59,432 Gentlemen, I'm honored to see you. 430 00:24:59,507 --> 00:25:01,432 Narrator: A new york lawyer hears that petroleum 431 00:25:01,507 --> 00:25:02,992 Can be used in lamps. 432 00:25:03,027 --> 00:25:04,359 Actor as benjamin silliman: This will be one of your greatest 433 00:25:04,434 --> 00:25:05,472 Opportunities ever. 434 00:25:05,507 --> 00:25:07,319 Narrator: Up to this point, lamps 435 00:25:07,394 --> 00:25:10,512 Are fueled by whale oil, a commodity that even 436 00:25:10,547 --> 00:25:13,712 Back then is becoming scarce. 437 00:25:13,747 --> 00:25:18,952 The oil rush in america begins in 1859 with the pennsylvania 438 00:25:19,027 --> 00:25:21,319 Rock oil company, which commissions 439 00:25:21,394 --> 00:25:24,992 An adventurous character named edwin drake to track 440 00:25:25,027 --> 00:25:27,792 Down indian sources of oil. 441 00:25:27,827 --> 00:25:30,272 Seneca man: Try it. 442 00:25:30,347 --> 00:25:33,872 Narrator: No one could possibly have imagined the process 443 00:25:33,907 --> 00:25:34,999 This sets in motion. 444 00:25:38,867 --> 00:25:39,872 All right. 445 00:25:39,907 --> 00:25:41,479 Where's it from? 446 00:25:41,554 --> 00:25:44,512 Follow the way. 447 00:25:44,547 --> 00:25:46,312 Narrator: Drake is directed to the northwestern 448 00:25:46,387 --> 00:25:47,799 Corner of pennsylvania. 449 00:25:47,874 --> 00:25:49,439 [wagon clattering] 450 00:25:51,107 --> 00:25:54,792 At that time, nobody knows exactly how to extract 451 00:25:54,867 --> 00:25:56,279 Large quantities of oil. 452 00:26:00,067 --> 00:26:03,632 Determined to get at the source, drake starts digging. 453 00:26:03,667 --> 00:26:05,879 [pick-axe impacts] 454 00:26:07,907 --> 00:26:09,232 [heavy breathing] 455 00:26:09,307 --> 00:26:10,759 It's painful work. 456 00:26:18,867 --> 00:26:25,159 In the end, he does find oil, but it's not much. 457 00:26:25,234 --> 00:26:26,632 [laughs] 458 00:26:26,707 --> 00:26:32,472 Narrator: Drake realizes that he must dig deeper 459 00:26:32,547 --> 00:26:36,999 And eventually tries a drilling tower that allows a steel pipe 460 00:26:37,074 --> 00:26:38,719 To be forced into the ground. 461 00:26:42,507 --> 00:26:44,432 Tension! 462 00:26:44,467 --> 00:26:50,632 Narrator: On August 27, 1859, he hits the jackpot, a reserve 463 00:26:50,707 --> 00:26:53,712 Of oil about 70 feet down that can produce 464 00:26:53,747 --> 00:26:57,072 400 gallons of crude a day. 465 00:26:57,107 --> 00:27:01,792 It's the beginning of oil fever. 466 00:27:01,827 --> 00:27:03,639 [ominous music] 467 00:27:03,714 --> 00:27:07,072 The new fuel, which is rich in energy and comparatively cheap, 468 00:27:07,107 --> 00:27:10,199 Spreads around the world and has been in continuous use 469 00:27:10,274 --> 00:27:12,752 Since then. 470 00:27:12,787 --> 00:27:15,392 But of course, it comes at a cost. 471 00:27:15,427 --> 00:27:18,672 Oil harms the environment, not only when it's burned, 472 00:27:18,707 --> 00:27:21,079 But when gasoline and diesel are distilled from it. 473 00:27:23,987 --> 00:27:28,112 Cars above all are responsible for what scientists call 474 00:27:28,147 --> 00:27:31,272 The great acceleration, the dramatic surge 475 00:27:31,347 --> 00:27:34,192 In human activities since the 1950s 476 00:27:34,227 --> 00:27:37,392 And their impacts on the earth. 477 00:27:37,427 --> 00:27:39,392 One of the key developments we see, of course, 478 00:27:39,427 --> 00:27:41,272 Is the emission of carbon dioxide 479 00:27:41,347 --> 00:27:43,799 To the atmosphere as the most important gas 480 00:27:43,874 --> 00:27:45,479 That is warming the climate. 481 00:27:45,554 --> 00:27:49,592 And that, for much of the preceding 10,000 years, 482 00:27:49,667 --> 00:27:52,512 Was around 280 parts per million, which 483 00:27:52,547 --> 00:27:54,592 Is a unit we use to measure it. 484 00:27:54,627 --> 00:27:56,592 And by mid-20th century, it had only 485 00:27:56,627 --> 00:27:59,632 Crept up to about 300 or 310. 486 00:27:59,641 --> 00:28:04,519 But after 1950, it's gone from 310 or so all the way up 487 00:28:04,594 --> 00:28:06,352 To about 405. 488 00:28:06,387 --> 00:28:09,232 So that's a key parameter that was slowly changing 489 00:28:09,267 --> 00:28:12,592 And then went up. 490 00:28:12,627 --> 00:28:15,952 Narrator: In the year 2009, more than a billion cars 491 00:28:15,961 --> 00:28:17,959 Are on the road worldwide. 492 00:28:18,034 --> 00:28:22,952 By 2025, that figure could reach 2 billion. 493 00:28:23,027 --> 00:28:25,319 The vast majority are private cars. 494 00:28:25,394 --> 00:28:28,192 Once again, the united states leads the pack 495 00:28:28,227 --> 00:28:32,199 With the most cars of any country, 496 00:28:32,274 --> 00:28:35,632 Perhaps due in part to another american invention that makes 497 00:28:35,667 --> 00:28:38,752 Car engines run more smoothly without knocking, 498 00:28:38,787 --> 00:28:40,679 Tetraethyl lead, or tel. 499 00:28:44,754 --> 00:28:47,872 When it was introduced in 1923, the press 500 00:28:47,907 --> 00:28:50,512 Reported that several people had died of lead poisoning 501 00:28:50,547 --> 00:28:51,999 During its development. 502 00:28:54,867 --> 00:28:58,199 Chemical engineer thomas midgley tries damage control 503 00:28:58,274 --> 00:28:59,839 With an impressive pr stunt. 504 00:29:06,147 --> 00:29:07,232 Actor as thomas midgley: Tetraethyl. 505 00:29:07,267 --> 00:29:08,592 [gasps] 506 00:29:08,667 --> 00:29:10,632 [shutter clicks] 507 00:29:10,707 --> 00:29:15,232 Narrator: On October 30, 1924, he performs a demonstration 508 00:29:15,267 --> 00:29:18,672 And tells the press that even daily contact with tel 509 00:29:18,707 --> 00:29:20,592 Is completely safe. 510 00:29:20,627 --> 00:29:24,199 And my hands, as you see, stay absolutely clean and pure. 511 00:29:24,274 --> 00:29:26,199 Any more questions? 512 00:29:26,274 --> 00:29:28,272 Narrator: Midgley himself eventually become 513 00:29:28,307 --> 00:29:30,432 Sick from lead poisoning. 514 00:29:30,467 --> 00:29:34,152 And yet, leaded gas becomes the worldwide standard 515 00:29:34,227 --> 00:29:36,672 For the next 50 years. 516 00:29:36,707 --> 00:29:39,872 Co2 emissions are increasing every year. 517 00:29:39,907 --> 00:29:44,632 The us is responsible for 15% and south america, 6%. 518 00:29:44,707 --> 00:29:48,112 Europe accounts for 10%, 519 00:29:48,147 --> 00:29:54,199 Africa 4%, and russia 5%. 520 00:29:54,754 --> 00:29:59,392 China emits the most at 28%, mostly because it's 521 00:29:59,427 --> 00:30:01,472 The largest producer of consumer goods 522 00:30:01,481 --> 00:30:03,072 For the rest of the world. 523 00:30:03,107 --> 00:30:06,032 As we consume earth's natural resources, 524 00:30:06,107 --> 00:30:09,232 We're effectively transforming geological time 525 00:30:09,267 --> 00:30:13,112 Into human time, using up reserves that took 526 00:30:13,187 --> 00:30:14,439 Millions of years to create. 527 00:30:17,427 --> 00:30:20,032 And with the help of science and technology, 528 00:30:20,067 --> 00:30:23,159 We're moving faster and faster, consuming more 529 00:30:23,234 --> 00:30:24,919 And more at breathtaking speed. 530 00:30:28,594 --> 00:30:32,839 What happens when we don't give earth time to replenish itself? 531 00:30:35,987 --> 00:30:39,719 It's one of the biggest questions of the age of humans. 532 00:30:44,147 --> 00:30:47,439 [peaceful music] 533 00:30:48,987 --> 00:30:52,272 Air knows no country, borders, or boundaries. 534 00:30:52,307 --> 00:30:57,432 We all share each other's pollution in one atmosphere. 535 00:30:57,507 --> 00:31:00,512 Nasa scientists at the goddard space flight center 536 00:31:00,547 --> 00:31:05,432 Track the air quality of planet earth. 537 00:31:05,507 --> 00:31:09,872 What we see here is air pollution across the globe, 538 00:31:09,907 --> 00:31:12,672 And we see the different sources of air pollution 539 00:31:12,707 --> 00:31:15,312 And how they're being transported across the globe. 540 00:31:15,347 --> 00:31:17,112 And in white, we see this is mostly 541 00:31:17,187 --> 00:31:21,392 Man-made, anthropogenic emissions that cause pollution, 542 00:31:21,427 --> 00:31:26,272 And we see a lot of that, especially here over in china. 543 00:31:26,347 --> 00:31:29,319 Air pollution is a truly global problem. 544 00:31:29,394 --> 00:31:32,632 It gets emitted locally, but then it can be transported 545 00:31:32,707 --> 00:31:34,952 Across the ocean, and it can reach 546 00:31:35,027 --> 00:31:40,912 Places far away from where it actually originated. 547 00:31:40,947 --> 00:31:43,432 We know that there are approximately 8 million 548 00:31:43,507 --> 00:31:48,112 Deaths per year that is directly attributable to air pollution. 549 00:31:48,147 --> 00:31:53,152 That's one out of nine deaths every year. 550 00:31:53,187 --> 00:31:54,999 Narrator: Changes to our atmosphere affect 551 00:31:55,074 --> 00:31:57,319 Not just the air we breathe-- 552 00:31:57,394 --> 00:32:01,232 They're impacting our weather, too. 553 00:32:01,267 --> 00:32:04,352 As the world gets warmer, storms are becoming 554 00:32:04,361 --> 00:32:07,272 More damaging and more deadly. 555 00:32:07,347 --> 00:32:09,712 [dramatic music] 556 00:32:09,747 --> 00:32:13,552 Cyclone formation is increasing, especially in the north 557 00:32:13,627 --> 00:32:16,992 Atlantic, and catastrophic storms are happening with more 558 00:32:17,027 --> 00:32:22,192 Frequency now than they did just 50 years ago, causing damage 559 00:32:22,227 --> 00:32:23,399 In the billions of dollars. 560 00:32:26,754 --> 00:32:30,912 In the winter of 2019, it seems that all of australia 561 00:32:30,947 --> 00:32:32,592 Is on fire. 562 00:32:32,627 --> 00:32:37,232 After an unusually dry winter, bushfires rage up and down 563 00:32:37,267 --> 00:32:39,159 The eastern coast of the country, 564 00:32:39,234 --> 00:32:42,832 Destroying almost 3,000 homes. 565 00:32:42,841 --> 00:32:48,432 It kills dozens of people and more than a billion animals. 566 00:32:48,507 --> 00:32:51,712 Though the full causes of the disaster aren't yet known, 567 00:32:51,787 --> 00:32:54,912 It's no longer possible to dismiss the effect of climate 568 00:32:54,947 --> 00:32:57,752 Change on events like this. 569 00:32:57,827 --> 00:32:59,959 Today's technology gives us the ability 570 00:33:00,034 --> 00:33:02,359 To predict and track weather better than it 571 00:33:02,434 --> 00:33:04,832 Did for previous generations. 572 00:33:04,867 --> 00:33:06,912 But even our best inventions can't save 573 00:33:06,947 --> 00:33:09,112 Us from cataclysmic events. 574 00:33:09,187 --> 00:33:11,799 And according to scientists worldwide, 575 00:33:11,874 --> 00:33:15,072 It's only going to get worse. 576 00:33:15,147 --> 00:33:18,472 Tim winton: My ancestors and yours did, to a great extent, 577 00:33:18,547 --> 00:33:20,192 Live at the mercy of nature. 578 00:33:20,227 --> 00:33:23,959 The weather was the chief impact on their life. 579 00:33:24,034 --> 00:33:26,272 The great irony is that our effect on nature 580 00:33:26,307 --> 00:33:30,032 Is now to the degree that we determine the weather. 581 00:33:30,067 --> 00:33:32,832 But of course, that means that we are now more subject 582 00:33:32,867 --> 00:33:35,479 And, in the future, will be more subject to the weather 583 00:33:35,554 --> 00:33:38,432 And more subject to the vagaries of nature 584 00:33:38,467 --> 00:33:40,592 Than our ancestors were. 585 00:33:40,627 --> 00:33:43,399 [soaring music] 586 00:33:45,234 --> 00:33:48,752 Narrator: Finding alternatives to fossil fuels will help. 587 00:33:48,787 --> 00:33:50,912 In the middle of the last century, 588 00:33:50,947 --> 00:33:53,072 It appeared that nuclear energy might 589 00:33:53,147 --> 00:33:55,319 Provide the clean, cheap solution 590 00:33:55,394 --> 00:33:58,272 That would save the world. 591 00:33:58,307 --> 00:34:02,192 Nuclear fission has been used since 1954 to create 592 00:34:02,201 --> 00:34:04,912 Electricity, and the russians built the world's 593 00:34:04,947 --> 00:34:07,912 First nuclear reactor. 594 00:34:07,987 --> 00:34:10,832 Russia has dozens of nuclear plants today, 595 00:34:10,867 --> 00:34:15,319 But the world knows the most about just one, chernobyl. 596 00:34:15,394 --> 00:34:16,672 [speaking russian] 597 00:34:16,707 --> 00:34:18,199 Interpreter 1: At school, they told us 598 00:34:18,274 --> 00:34:20,472 That a matchbox-sized piece of uranium 599 00:34:20,547 --> 00:34:23,792 Can produce as much energy as a trainload of coal. 600 00:34:23,801 --> 00:34:27,159 It was generally perceived as an intellectual, high-tech, 601 00:34:27,234 --> 00:34:30,072 Trendy, elite occupation. 602 00:34:30,147 --> 00:34:33,072 I had the impression that it was an honorable and top-notch job 603 00:34:33,147 --> 00:34:34,352 To be a nuclear engineer. 604 00:34:34,361 --> 00:34:35,679 [speaking russian] 605 00:34:38,947 --> 00:34:43,952 Narrator: On April 26, 1986, a series of fateful events 606 00:34:43,961 --> 00:34:45,632 Occurs. 607 00:34:45,641 --> 00:34:49,872 A safety test is being performed at the chernobyl station. 608 00:34:49,907 --> 00:34:53,112 Human error and technical faults combine 609 00:34:53,187 --> 00:34:57,112 To create overheating that leads to an explosion in reactor 610 00:34:57,187 --> 00:34:58,672 Block 4. 611 00:34:58,707 --> 00:35:02,272 It's called an mca, the maximum credible 612 00:35:02,307 --> 00:35:06,472 Accident, a nuclear disaster. 613 00:35:06,547 --> 00:35:11,479 Everyone within a radius of 30 miles is evacuated. 614 00:35:11,554 --> 00:35:18,512 400,000 people become homeless, and 31 people die. 615 00:35:18,547 --> 00:35:20,672 Alexey breus: [speaking russian] 616 00:35:20,681 --> 00:35:22,992 Interpreter 1: I guess the main outcome of chernobyl 617 00:35:23,027 --> 00:35:28,352 For me is that it divided my life into before and after. 618 00:35:28,361 --> 00:35:32,792 It changed my life dramatically. 619 00:35:32,867 --> 00:35:36,272 Life is very fragile, and it's very easy to destroy it 620 00:35:36,347 --> 00:35:40,592 All by pressing just one button if, behind that button, 621 00:35:40,667 --> 00:35:43,712 There is a multitude of different man-made systems. 622 00:35:43,747 --> 00:35:45,839 [speaking russian] 623 00:35:54,787 --> 00:35:57,552 Narrator: Accidents like those at chernobyl 624 00:35:57,587 --> 00:36:01,392 And the 2011 disaster in fukushima, japan 625 00:36:01,427 --> 00:36:03,552 Have caused some countries to make 626 00:36:03,587 --> 00:36:06,672 The decision that the risks of nuclear power 627 00:36:06,707 --> 00:36:08,159 Are just too high. 628 00:36:15,667 --> 00:36:17,399 [crows cawing] 629 00:36:19,481 --> 00:36:20,992 [speaking german] 630 00:36:21,001 --> 00:36:22,032 Interpreter 1: Today, we are at a crossroads 631 00:36:22,107 --> 00:36:24,512 When it comes to nuclear energy. 632 00:36:24,547 --> 00:36:27,392 Soon, the first countries, including germany, 633 00:36:27,427 --> 00:36:30,839 Will have completely closed down their nuclear reactors. 634 00:36:30,914 --> 00:36:32,559 Other countries will follow that example. 635 00:36:35,714 --> 00:36:41,072 Narrator: In the year 2019, there are 444 nuclear reactors 636 00:36:41,107 --> 00:36:45,639 Operating around the world, in the united states and europe, 637 00:36:45,714 --> 00:36:49,319 And in russia, china, japan, and elsewhere. 638 00:36:52,547 --> 00:36:54,032 Though the number of nuclear plants 639 00:36:54,067 --> 00:36:57,152 Overall is expected to decline worldwide, 640 00:36:57,161 --> 00:37:00,072 Not all scientists agree that closing them 641 00:37:00,147 --> 00:37:03,392 Is a good idea, since they provide a clean source 642 00:37:03,427 --> 00:37:06,832 Of almost unlimited energy. 643 00:37:06,841 --> 00:37:10,359 Still, the risks remain, and nuclear waste 644 00:37:10,434 --> 00:37:13,072 Disposal is another concern. 645 00:37:13,107 --> 00:37:15,432 Waste that's low in radioactivity 646 00:37:15,507 --> 00:37:19,639 Is safe for shallow burial, but dealing with high-level waste 647 00:37:19,714 --> 00:37:23,232 Is complex and controversial. 648 00:37:23,307 --> 00:37:26,352 One of the first deep repositories for nuclear waste 649 00:37:26,387 --> 00:37:30,112 In europe is in a former salt mine near the german city 650 00:37:30,147 --> 00:37:31,712 Of salzgitter. 651 00:37:31,787 --> 00:37:34,512 Radioactive material will be stored here 652 00:37:34,547 --> 00:37:37,959 At a depth of about 3,300 feet in specially 653 00:37:38,034 --> 00:37:40,072 Constructed chambers. 654 00:37:40,147 --> 00:37:43,792 By the year 2060, the chamber will be full 655 00:37:43,827 --> 00:37:48,432 And then sealed permanently, toxic to plants and animals 656 00:37:48,467 --> 00:37:51,272 For millions of years. 657 00:37:51,347 --> 00:37:55,472 With every form of energy, we humans weigh the benefits 658 00:37:55,481 --> 00:37:57,479 Against the dangers. 659 00:37:57,554 --> 00:38:01,152 But today, it's clear our choices could 660 00:38:01,187 --> 00:38:03,359 Have disastrous consequences. 661 00:38:08,787 --> 00:38:11,952 America in the early 1900s. 662 00:38:11,961 --> 00:38:13,952 Thomas midgley didn't just discover 663 00:38:13,961 --> 00:38:16,632 A lead additive for gasoline. 664 00:38:16,707 --> 00:38:18,832 He's also responsible for creating 665 00:38:18,867 --> 00:38:21,432 Freon, the coolant that fuels air 666 00:38:21,507 --> 00:38:23,872 Conditioners and refrigerators. 667 00:38:23,907 --> 00:38:27,952 In 1930, he calls another press conference 668 00:38:27,961 --> 00:38:32,352 To show that his new gas is safer than existing coolants 669 00:38:32,387 --> 00:38:34,512 By inhaling it. 670 00:38:34,547 --> 00:38:36,799 [sucking tube] 671 00:38:39,874 --> 00:38:43,712 Midgley survives this presentation unharmed. 672 00:38:43,747 --> 00:38:47,792 But once again, what seems like a success for the scientist 673 00:38:47,827 --> 00:38:52,432 Comes with unforeseen consequences. 674 00:38:52,467 --> 00:38:54,199 [speaking german] 675 00:38:54,274 --> 00:38:56,992 Interpreter 1: Thomas midgley is a tragic figure in history in 676 00:38:57,001 --> 00:39:00,032 So far as he made two ingenious inventions at the beginning 677 00:39:00,067 --> 00:39:02,832 Of the 20th century which had an enormous impact 678 00:39:02,867 --> 00:39:07,312 On the age of humans, and thus, on our environment. 679 00:39:07,347 --> 00:39:11,432 We all know about leaded fuel, yet it is cfc, the gas which 680 00:39:11,507 --> 00:39:13,319 Is responsible for the ozone hole, that 681 00:39:13,394 --> 00:39:14,952 Had incredible consequences. 682 00:39:15,027 --> 00:39:16,799 [speaking german] 683 00:39:20,594 --> 00:39:24,432 Narrator: Freon is one of a few dozen chlorofluorocarbons, 684 00:39:24,467 --> 00:39:26,632 Or cfcs for short. 685 00:39:26,707 --> 00:39:29,792 They become widely used in aerosolized products 686 00:39:29,801 --> 00:39:34,359 Until the mid-1970s, when scientists sound the alarm 687 00:39:34,434 --> 00:39:38,032 That cfcs are destroying the ozone layer, which is 688 00:39:38,067 --> 00:39:40,912 Crucial for life on our planet. 689 00:39:40,947 --> 00:39:44,032 Earth's atmosphere is composed of several layers. 690 00:39:44,067 --> 00:39:47,752 Just outside the troposphere lies the stratosphere, 691 00:39:47,827 --> 00:39:51,232 And then the mesosphere furthest out. 692 00:39:51,267 --> 00:39:55,792 The ozone layer is located here, between 9 and 18 miles 693 00:39:55,801 --> 00:39:57,799 Above the earth's surface. 694 00:39:57,874 --> 00:40:01,912 Ozone absorbs ultraviolet light called uvb that harms 695 00:40:01,987 --> 00:40:05,072 Humans, crops, and marine life. 696 00:40:05,107 --> 00:40:09,392 Industrialized nations finally prohibit the use of cfc gases 697 00:40:09,427 --> 00:40:16,312 In 1989, and since then, the ozone layer has regenerated. 698 00:40:16,387 --> 00:40:20,032 It's an example of scientists' warnings being taken seriously 699 00:40:20,067 --> 00:40:24,152 And of the success we humans can have when we work together. 700 00:40:24,227 --> 00:40:26,039 [waves lapping] 701 00:40:27,714 --> 00:40:30,952 We still have stratospheric ozone. 702 00:40:31,027 --> 00:40:32,832 The governments and the private sector 703 00:40:32,867 --> 00:40:34,432 Should have listened earlier. 704 00:40:34,467 --> 00:40:37,392 But in a relative scheme, it has become, 705 00:40:37,467 --> 00:40:39,752 In my opinion, a reasonable success 706 00:40:39,827 --> 00:40:43,632 Story of scientific evidence being used by governments 707 00:40:43,667 --> 00:40:46,152 And by the private sector to solve 708 00:40:46,227 --> 00:40:48,832 A global environmental issue. 709 00:40:48,867 --> 00:40:52,039 [dramatic music] 710 00:40:52,754 --> 00:40:55,952 Narrator: The sun and wind are also sources of energy that 711 00:40:55,987 --> 00:40:58,512 Hold promise for the future. 712 00:40:58,521 --> 00:41:03,472 Solar energy is transformed into electricity in two ways. 713 00:41:03,507 --> 00:41:07,072 In solar thermal power stations, the light of the sun 714 00:41:07,107 --> 00:41:10,679 Creates steam that drives turbines. 715 00:41:13,827 --> 00:41:16,112 The other method is photovoltaic, 716 00:41:16,147 --> 00:41:19,072 In which solar cells transform the energy of light 717 00:41:19,107 --> 00:41:21,592 Directly into electricity. 718 00:41:21,667 --> 00:41:23,472 The advantage is that it can be used 719 00:41:23,507 --> 00:41:26,032 On a small scale on the roofs of houses 720 00:41:26,067 --> 00:41:28,352 And individual developments. 721 00:41:28,387 --> 00:41:31,712 In simple mathematical terms, the wind and sun can 722 00:41:31,747 --> 00:41:35,952 Provide all the energy we need. 723 00:41:35,987 --> 00:41:38,672 The abundance of natural energy that's 724 00:41:38,707 --> 00:41:40,352 Coming to this earth is enormous, more 725 00:41:40,387 --> 00:41:43,072 Than we could ever utilize in terms of solar 726 00:41:43,107 --> 00:41:45,272 And wind and geothermal. 727 00:41:45,347 --> 00:41:47,479 They're basically limitless resources. 728 00:41:47,554 --> 00:41:49,272 So if we can build the technologies 729 00:41:49,347 --> 00:41:51,952 That tap into them inexpensively, 730 00:41:51,987 --> 00:41:54,432 We can change everything. 731 00:41:54,507 --> 00:41:56,512 Narrator: Alternatives are certainly needed, 732 00:41:56,521 --> 00:41:58,952 As the demand for electricity is increasing 733 00:41:59,027 --> 00:42:00,479 Rapidly around the globe. 734 00:42:04,627 --> 00:42:08,432 According to some estimates, the 27 largest cities 735 00:42:08,467 --> 00:42:12,839 Consume almost 8% of the world's energy. 736 00:42:16,547 --> 00:42:20,072 [soaring music] 737 00:42:20,147 --> 00:42:23,712 And there's one more big energy hog that's a relative newcomer 738 00:42:23,747 --> 00:42:25,712 On the scene-- 739 00:42:25,747 --> 00:42:27,712 The internet. 740 00:42:27,747 --> 00:42:31,552 One study calculates that if the internet were a country, 741 00:42:31,587 --> 00:42:33,799 It would be the sixth largest consumer 742 00:42:33,874 --> 00:42:36,679 Of electricity in the world. 743 00:42:36,754 --> 00:42:40,592 Every minute, 2 and 1/2 billion people are online, 744 00:42:40,627 --> 00:42:42,999 And the demand is steadily increasing. 745 00:42:46,594 --> 00:42:50,992 We need policies to stimulate a transition from fossil fuels 746 00:42:51,001 --> 00:42:52,912 To renewable energy. 747 00:42:52,947 --> 00:42:55,712 But we also need behavior change. 748 00:42:55,747 --> 00:42:58,839 We need individuals, we need communities, 749 00:42:58,914 --> 00:43:01,159 We need governments and the private sector 750 00:43:01,234 --> 00:43:03,592 To recognize their current behavior 751 00:43:03,667 --> 00:43:06,432 Is inconsistent with a more sustainable 752 00:43:06,467 --> 00:43:07,792 World in the future. 753 00:43:07,801 --> 00:43:10,359 So technology will play a key role, 754 00:43:10,434 --> 00:43:12,792 But it's only one element of how we 755 00:43:12,867 --> 00:43:15,959 Need to address these large, global-scale issues. 756 00:43:18,201 --> 00:43:22,359 Narrator: How much change will people be willing to make? 757 00:43:22,434 --> 00:43:27,639 We learned with cfcs that it's possible to undo some damage. 758 00:43:27,714 --> 00:43:32,432 That's a success story from the age of humans. 759 00:43:32,507 --> 00:43:35,159 What will the next one be? 760 00:43:35,234 --> 00:43:39,959 From fossil fuels to nuclear power and alternative energies, 761 00:43:40,034 --> 00:43:42,912 Will we choose wisely? 762 00:43:42,947 --> 00:43:45,072 One thing's for sure-- 763 00:43:45,107 --> 00:43:47,952 The choices we make now will affect 764 00:43:47,987 --> 00:43:54,359 Not just our own lives, but the lives of humanity to come.