1
00:00:00,081 --> 00:00:02,870
(air whooshing)

2
00:00:02,870 --> 00:00:03,978
Extinction,

3
00:00:03,978 --> 00:00:05,870
(air whooshing)

4
00:00:05,870 --> 00:00:08,773
a daunting and confusing word,

5
00:00:09,650 --> 00:00:14,420
a natural force in nature that sees the end of some species,

6
00:00:14,420 --> 00:00:16,340
creating space for others.

7
00:00:16,340 --> 00:00:19,090
(soft music)

8
00:00:19,090 --> 00:00:23,033
A force so powerful. It wiped out the dinosaurs.

9
00:00:23,892 --> 00:00:27,140
(asteroid striking)

10
00:00:27,140 --> 00:00:29,550
We hear in the news every day

11
00:00:29,550 --> 00:00:32,793
that animal species are getting rarer and rarer.

12
00:00:33,970 --> 00:00:38,700
Some scientists say we are entering a sick extinction.

13
00:00:38,700 --> 00:00:41,543
Unlike anything the world has ever seen before.

14
00:00:42,815 --> 00:00:43,648
(fire crackling)

15
00:00:43,648 --> 00:00:46,400
There can be many causes of extinction

16
00:00:46,400 --> 00:00:48,353
and we have a lot to lean,

17
00:00:49,866 --> 00:00:51,512
but one thing is for sure,

18
00:00:51,512 --> 00:00:53,750
(iceberg groaning)

19
00:00:53,750 --> 00:00:55,997
there is no coming back.

20
00:00:55,997 --> 00:00:58,414
(soft music)

21
00:01:05,540 --> 00:01:08,830
It's easy to be confused about what extinction is,

22
00:01:08,830 --> 00:01:11,215
how it happens and what it means.

23
00:01:11,215 --> 00:01:13,970
(soft music)

24
00:01:13,970 --> 00:01:16,000
In its simplest form,

25
00:01:16,000 --> 00:01:19,243
it's when more members of a species are dying than are born.

26
00:01:20,680 --> 00:01:22,883
Many factors can cause this to happen,

27
00:01:24,520 --> 00:01:27,613
but one thing's for sure it comes to us all.

28
00:01:28,560 --> 00:01:31,653
Extinction is a part of life on earth.

29
00:01:34,127 --> 00:01:36,544
(soft music)

30
00:01:39,850 --> 00:01:43,900
Much of what we know comes from clues buried in the earth.

31
00:01:43,900 --> 00:01:46,960
Faint ghosts of long lost life.

32
00:01:46,960 --> 00:01:48,868
The victims of extinction.

33
00:01:48,868 --> 00:01:51,285
(soft music)

34
00:01:52,520 --> 00:01:53,750
From the fossil record,

35
00:01:53,750 --> 00:01:56,180
we can piece together the Earth's history

36
00:01:56,180 --> 00:01:58,534
and understand the role extinction has played.

37
00:01:58,534 --> 00:02:00,960
(soft music)

38
00:02:00,960 --> 00:02:03,300
90% of all species

39
00:02:03,300 --> 00:02:07,090
that have ever lived on the planet are extinct.

40
00:02:07,090 --> 00:02:09,975
They had their time and now they are gone.

41
00:02:09,975 --> 00:02:12,220
(soft music)

42
00:02:12,220 --> 00:02:13,510
It's natural.

43
00:02:13,510 --> 00:02:16,150
Part of the process of evolution,

44
00:02:16,150 --> 00:02:18,530
one species evolving into another,

45
00:02:18,530 --> 00:02:21,200
or dying out and creating opportunities

46
00:02:21,200 --> 00:02:23,064
for new species to arise.

47
00:02:23,064 --> 00:02:26,150
(soft music)

48
00:02:26,150 --> 00:02:29,060
It's often a slow and steady decline.

49
00:02:29,060 --> 00:02:30,630
As a species is less able

50
00:02:30,630 --> 00:02:33,020
to cope with changing habitat and climate

51
00:02:34,460 --> 00:02:37,260
or the arrival of new competing species

52
00:02:37,260 --> 00:02:40,493
pressure from new predators or the decline of prey.

53
00:02:40,493 --> 00:02:42,910
(soft music)

54
00:02:43,780 --> 00:02:47,120
For whatever reason, their situation changes faster

55
00:02:47,120 --> 00:02:48,320
than they can adapt to it.

56
00:02:48,320 --> 00:02:51,401
And so their numbers begin to drop.

57
00:02:51,401 --> 00:02:53,818
(soft music)

58
00:02:59,140 --> 00:03:02,580
This is known as background extinction rate

59
00:03:03,520 --> 00:03:06,760
and happens naturally like a ticking clock,

60
00:03:06,760 --> 00:03:08,210
a biological baseline.

61
00:03:08,210 --> 00:03:10,627
(soft music)

62
00:03:12,570 --> 00:03:16,050
At a normal pace for every species lost,

63
00:03:16,050 --> 00:03:18,127
another evolves to replace it.

64
00:03:18,127 --> 00:03:20,544
(soft music)

65
00:03:21,810 --> 00:03:23,663
There are exceptions to the rules.

66
00:03:23,663 --> 00:03:26,080
(soft music)

67
00:03:28,660 --> 00:03:31,296
Sometimes something catastrophic happens.

68
00:03:31,296 --> 00:03:34,213
(asteroid roaring)

69
00:03:41,312 --> 00:03:44,060
There have been five major extinction events

70
00:03:44,060 --> 00:03:48,630
during the Earth's history, mostly caused by meteoric events

71
00:03:48,630 --> 00:03:51,546
or bouts of increased volcanic activity.

72
00:03:51,546 --> 00:03:54,463
(volcano rumbling)

73
00:04:13,705 --> 00:04:16,622
(dinosaur tapping)

74
00:04:19,320 --> 00:04:23,020
The fifth event in the sequence known as the big five

75
00:04:23,020 --> 00:04:24,694
is the most famous.

76
00:04:24,694 --> 00:04:26,270
(dinosaurs grunt)

77
00:04:26,270 --> 00:04:31,100
66 million years ago, an asteroid the size of a city

78
00:04:31,100 --> 00:04:34,020
hit the earth on the coast of Mexico,

79
00:04:34,020 --> 00:04:37,183
sending up clouds of debris that blotted out the sun.

80
00:04:37,183 --> 00:04:40,266
(asteroid whooshing)

81
00:04:52,110 --> 00:04:54,733
It famously killed the last of the dinosaurs,

82
00:04:56,140 --> 00:05:00,463
but also took with it at least 75% of lifeforms.

83
00:05:02,470 --> 00:05:05,651
Like all mass extinctions. It was devastating.

84
00:05:05,651 --> 00:05:07,710
(air whooshing)

85
00:05:07,710 --> 00:05:11,089
But also created a land of opportunities for the survivors.

86
00:05:11,089 --> 00:05:13,890
(air whooshing)

87
00:05:13,890 --> 00:05:17,740
Without the huge dinosaurs that dominated the landscape,

88
00:05:17,740 --> 00:05:20,560
the small mammals that lived in their shadows

89
00:05:20,560 --> 00:05:22,863
had the chance to diversify.

90
00:05:22,863 --> 00:05:25,280
(soft music)

91
00:05:31,940 --> 00:05:35,370
It's when our own ancestors really got a foot in the door,

92
00:05:35,370 --> 00:05:38,328
(soft music)

93
00:05:38,328 --> 00:05:41,078
(birds chirping)

94
00:05:42,610 --> 00:05:44,620
by studying the fossil record,

95
00:05:44,620 --> 00:05:48,380
scientists have estimated a background rate,

96
00:05:48,380 --> 00:05:51,790
the natural speed at which species die out

97
00:05:51,790 --> 00:05:53,853
outside of catastrophic events.

98
00:05:55,530 --> 00:05:57,073
And that reveals a problem.

99
00:05:57,073 --> 00:05:59,490
(soft music)

100
00:05:59,490 --> 00:06:02,850
Right now, the current extinction rate

101
00:06:02,850 --> 00:06:07,460
is at least 10 times, and perhaps as much as 10,000 times

102
00:06:07,460 --> 00:06:09,371
faster than it should be.

103
00:06:09,371 --> 00:06:11,880
(soft music)

104
00:06:11,880 --> 00:06:16,870
We're almost certainly in a sixth mass extinction event,

105
00:06:16,870 --> 00:06:20,453
but this one's unlike any the world has ever seen before.

106
00:06:22,120 --> 00:06:26,350
The question is, how much of this new wave of extinction

107
00:06:26,350 --> 00:06:28,300
is because of us?

108
00:06:28,300 --> 00:06:31,872
And what does it mean for the planet and our future on it?

109
00:06:31,872 --> 00:06:35,086
(water roaring)

110
00:06:35,086 --> 00:06:37,503
(soft music)

111
00:06:41,643 --> 00:06:45,020
(air whooshing)

112
00:06:45,020 --> 00:06:48,243
Extinction is a very hard thing to study or measure.

113
00:06:48,243 --> 00:06:49,351
(air whooshing)

114
00:06:49,351 --> 00:06:51,768
(soft music)

115
00:06:55,090 --> 00:06:56,070
We don't even know

116
00:06:56,070 --> 00:06:58,290
how many species we shared this planet with.

117
00:06:58,290 --> 00:07:01,040
(birds chirping)

118
00:07:02,700 --> 00:07:05,840
We know, there are at least 2 million

119
00:07:05,840 --> 00:07:08,960
and estimates suggest perhaps as many as 8 million

120
00:07:08,960 --> 00:07:10,042
other forms of life.

121
00:07:10,042 --> 00:07:12,792
(water bubbling)

122
00:07:14,330 --> 00:07:17,270
New species are discovered all the time.

123
00:07:17,270 --> 00:07:20,190
And some of the new ones are already endangered,

124
00:07:20,190 --> 00:07:22,330
before we even know that they exist.

125
00:07:22,330 --> 00:07:25,080
(birds chirping)

126
00:07:26,710 --> 00:07:29,670
Today, 25,000 plants

127
00:07:29,670 --> 00:07:31,945
and animals are on the brink.

128
00:07:31,945 --> 00:07:33,620
(soft music)

129
00:07:33,620 --> 00:07:36,030
When you break down the statistics,

130
00:07:36,030 --> 00:07:37,177
they're pretty frightening.

131
00:07:37,177 --> 00:07:39,927
(water bubbling)

132
00:07:41,620 --> 00:07:43,016
One third of corals,

133
00:07:43,016 --> 00:07:45,850
(water bubbling)

134
00:07:45,850 --> 00:07:46,683
sharks

135
00:07:47,570 --> 00:07:48,403
and rays

136
00:07:48,403 --> 00:07:49,760
(water bubbling)

137
00:07:49,760 --> 00:07:52,070
and freshwater mussels are endangered.

138
00:07:52,070 --> 00:07:54,350
(water bubbling)

139
00:07:54,350 --> 00:07:55,488
20% of fish,

140
00:07:55,488 --> 00:07:58,400
(water bubbling)

141
00:07:58,400 --> 00:07:59,886
a fifth of all reptiles,

142
00:07:59,886 --> 00:08:03,100
(birds chirping)

143
00:08:03,100 --> 00:08:04,293
a sixth of birds,

144
00:08:04,293 --> 00:08:06,710
(soft music)

145
00:08:10,910 --> 00:08:13,660
and a staggering quarter of all known mammals

146
00:08:13,660 --> 00:08:15,179
are facing extinction.

147
00:08:15,179 --> 00:08:17,596
(soft music)

148
00:08:18,720 --> 00:08:21,943
And nearly 70% of all plant species are threatened.

149
00:08:23,400 --> 00:08:26,270
Considering that they give us oxygen to breathe

150
00:08:26,270 --> 00:08:28,910
and other basis of the food chain.

151
00:08:28,910 --> 00:08:31,713
This is something we should be pretty concerned with.

152
00:08:33,230 --> 00:08:35,583
Even our closest relatives are in danger.

153
00:08:36,920 --> 00:08:39,862
Half of all primates are threatened with extinction.

154
00:08:39,862 --> 00:08:44,862
(baboons grunting)
(birds chirping)

155
00:08:45,670 --> 00:08:47,794
Why is it important for us to know.

156
00:08:47,794 --> 00:08:50,544
(frogs croaking)

157
00:08:54,460 --> 00:08:55,928
Take frogs example.

158
00:08:55,928 --> 00:08:58,678
(frogs croaking)

159
00:09:00,150 --> 00:09:01,460
Amphibians are very sensitive

160
00:09:01,460 --> 00:09:03,730
to changes in their environment.

161
00:09:03,730 --> 00:09:06,260
Things like poor water and air quality

162
00:09:06,260 --> 00:09:07,616
can cause them to die off.

163
00:09:07,616 --> 00:09:10,582
(frogs croaking)

164
00:09:10,582 --> 00:09:11,860
(water bubbling)

165
00:09:11,860 --> 00:09:13,420
If they're dying,

166
00:09:13,420 --> 00:09:17,110
it tells us there is something wrong with their habitat.

167
00:09:17,110 --> 00:09:20,927
And today a third of amphibians are facing extinction.

168
00:09:20,927 --> 00:09:23,177
(insects chirping)

169
00:09:23,177 --> 00:09:25,844
(air whooshing)

170
00:09:27,100 --> 00:09:29,450
The Earth's climate goes through natural periods

171
00:09:29,450 --> 00:09:30,687
of cooling and warming.

172
00:09:30,687 --> 00:09:33,790
(soft music)

173
00:09:33,790 --> 00:09:37,880
Not all animals can cope with their habitats getting warmer,

174
00:09:37,880 --> 00:09:39,663
wetter, cooler,

175
00:09:40,670 --> 00:09:41,980
or drier.

176
00:09:41,980 --> 00:09:44,983
The varied climate also brings changes in sea level,

177
00:09:45,860 --> 00:09:48,010
submerged land can rise

178
00:09:48,010 --> 00:09:50,547
linking previously separated land masses.

179
00:09:50,547 --> 00:09:52,964
(soft music)

180
00:09:55,730 --> 00:09:58,120
Allowing animals to travel to new areas

181
00:09:58,120 --> 00:10:00,600
where they might spread disease, hunt

182
00:10:00,600 --> 00:10:04,147
or out-compete native species causing extinction.

183
00:10:04,147 --> 00:10:06,564
(soft music)

184
00:10:11,330 --> 00:10:13,884
And it's not just animals that immigrate.

185
00:10:13,884 --> 00:10:16,301
(soft music)

186
00:10:18,908 --> 00:10:22,660
10,000 years ago at the end of the last ice age

187
00:10:22,660 --> 00:10:24,390
land bridges enable humans

188
00:10:24,390 --> 00:10:26,713
to walk from Asia into North America.

189
00:10:26,713 --> 00:10:29,130
(soft music)

190
00:10:34,760 --> 00:10:39,110
Soon after the continent giant mammals like mammoths,

191
00:10:39,110 --> 00:10:43,195
mastodons and giant armadillos became extinct.

192
00:10:43,195 --> 00:10:48,195
(footsteps tapping)
(elephant roars)

193
00:10:48,536 --> 00:10:51,536
(footsteps tapping)

194
00:10:56,120 --> 00:10:58,150
It's likely that the changing climate

195
00:10:58,150 --> 00:11:00,685
was already putting those species under stress.

196
00:11:00,685 --> 00:11:03,435
(elephant roars)

197
00:11:04,550 --> 00:11:07,550
But also very likely that he was hunting pressure

198
00:11:07,550 --> 00:11:10,069
from humans that drove them over the edge.

199
00:11:10,069 --> 00:11:12,336
(footsteps tapping)

200
00:11:12,336 --> 00:11:15,086
(elephant roars)

201
00:11:25,660 --> 00:11:29,590
In other parts of the world, humans were starting to farm

202
00:11:29,590 --> 00:11:32,400
switching from being nomadic hunter gatherers,

203
00:11:32,400 --> 00:11:35,750
to forming permanent settlements and changing habitats

204
00:11:35,750 --> 00:11:39,148
and plants and animals in them to suit their needs.

205
00:11:39,148 --> 00:11:40,987
(birds chirping)

206
00:11:40,987 --> 00:11:42,570
(animal mooing)

207
00:11:42,570 --> 00:11:44,987
(soft music)

208
00:11:53,230 --> 00:11:54,820
The domestication of livestock

209
00:11:54,820 --> 00:11:59,390
and crops has led to a continued trend of reduced diversity.

210
00:11:59,390 --> 00:12:02,350
As farmers have favored monocultures,

211
00:12:02,350 --> 00:12:04,632
single species that they want to harvest.

212
00:12:04,632 --> 00:12:07,049
(soft music)

213
00:12:12,100 --> 00:12:15,400
Domestic animals were bred from wild species that were tamed

214
00:12:17,150 --> 00:12:19,780
and then use to replace the wild species,

215
00:12:19,780 --> 00:12:22,158
which were gradually hunted to extinction.

216
00:12:22,158 --> 00:12:24,575
(soft music)

217
00:12:28,510 --> 00:12:32,200
The majestic aurochs once roamed across Europe and Asia,

218
00:12:32,200 --> 00:12:34,306
the great granddaddy of the domestic cow.

219
00:12:34,306 --> 00:12:36,973
(air whooshing)

220
00:12:38,160 --> 00:12:40,105
Running alongside herds of Tar-Pam,

221
00:12:40,105 --> 00:12:41,400
(birds chirping)

222
00:12:41,400 --> 00:12:43,468
the ancestor of our domestic horse.

223
00:12:43,468 --> 00:12:44,680
(birds chirping)

224
00:12:44,680 --> 00:12:47,940
These beautiful species, so vital to the development

225
00:12:47,940 --> 00:12:50,800
of human farming have been totally extinct

226
00:12:50,800 --> 00:12:52,100
for hundreds of years.

227
00:12:52,100 --> 00:12:53,510
(birds chirping)

228
00:12:53,510 --> 00:12:57,200
These are lookalikes bred back from ancient breeds.

229
00:12:57,200 --> 00:13:00,127
(birds chirping)

230
00:13:00,127 --> 00:13:01,800
(air whooshing)

231
00:13:01,800 --> 00:13:04,490
As shipping technologies improved

232
00:13:04,490 --> 00:13:06,690
global exploration saw the discovery

233
00:13:06,690 --> 00:13:08,308
of new resources to exploit

234
00:13:08,308 --> 00:13:10,260
(air whooshing)

235
00:13:10,260 --> 00:13:13,950
and the transfer of non-native species around the world,

236
00:13:13,950 --> 00:13:15,500
as people try to set up home

237
00:13:15,500 --> 00:13:17,405
on far-flung corners of the globe.

238
00:13:17,405 --> 00:13:19,822
(soft music)

239
00:13:29,440 --> 00:13:32,060
Island species have small populations

240
00:13:32,060 --> 00:13:33,601
and are especially vulnerable.

241
00:13:33,601 --> 00:13:36,018
(soft music)

242
00:13:38,530 --> 00:13:40,680
When people arrived on islands,

243
00:13:40,680 --> 00:13:43,163
a pattern was repeated over and over.

244
00:13:44,150 --> 00:13:47,500
Hunting animals, changing their habitats

245
00:13:47,500 --> 00:13:49,990
and introducing predatory species

246
00:13:49,990 --> 00:13:52,206
that they had no natural defense against.

247
00:13:52,206 --> 00:13:54,116
(air whooshing)

248
00:13:54,116 --> 00:13:56,150
(tortoise chucks)

249
00:13:56,150 --> 00:13:59,686
Many were hard hit, such as the giant tortoise.

250
00:13:59,686 --> 00:14:00,519
(footsteps tapping)

251
00:14:00,519 --> 00:14:03,269
(birds chirping)

252
00:14:04,250 --> 00:14:07,150
In the absence of predators or competition,

253
00:14:07,150 --> 00:14:10,430
the gentle giants have reached huge sizes,

254
00:14:10,430 --> 00:14:13,200
making them desirable sources of meat for sailors.

255
00:14:13,200 --> 00:14:15,617
(soft music)

256
00:14:24,155 --> 00:14:28,219
Their numbers were decimated and most species wiped out.

257
00:14:28,219 --> 00:14:30,636
(soft music)

258
00:14:34,810 --> 00:14:37,942
From the 1800s industry group.

259
00:14:37,942 --> 00:14:40,125
(log rambles)

260
00:14:40,125 --> 00:14:43,060
(seesaw roars)

261
00:14:43,060 --> 00:14:44,580
Ramping up extinction rates

262
00:14:44,580 --> 00:14:46,464
with their consumption and pollution.

263
00:14:46,464 --> 00:14:48,881
(soft music)

264
00:14:50,880 --> 00:14:53,060
There is no doubt this loss of species

265
00:14:53,060 --> 00:14:54,942
is directly tied to us.

266
00:14:54,942 --> 00:14:57,359
(soft music)

267
00:15:01,870 --> 00:15:05,366
Though extinction is final, there are different definitions.

268
00:15:05,366 --> 00:15:07,430
(air whooshing)

269
00:15:07,430 --> 00:15:10,963
For example, species can be locally extinct.

270
00:15:12,400 --> 00:15:15,940
The grizzly bear is the state symbol for California

271
00:15:15,940 --> 00:15:18,350
because when Europeans first arrived,

272
00:15:18,350 --> 00:15:19,716
the bears were abundant.

273
00:15:19,716 --> 00:15:22,133
(soft music)

274
00:15:30,796 --> 00:15:35,796
(soft music)
(bears grumbles)

275
00:15:36,530 --> 00:15:39,980
Grizzly bears still exist in the North of the continent,

276
00:15:39,980 --> 00:15:41,862
but are extinct in California.

277
00:15:41,862 --> 00:15:43,960
(leaves rattling)

278
00:15:43,960 --> 00:15:46,600
When there are too few examples of a species left

279
00:15:46,600 --> 00:15:49,220
to perform a function in an ecosystem,

280
00:15:49,220 --> 00:15:51,556
they are considered functionally extinct.

281
00:15:51,556 --> 00:15:53,973
(soft music)

282
00:15:59,200 --> 00:16:02,183
There are also species that are extinct in the wild.

283
00:16:03,670 --> 00:16:06,860
Although they have been reintroduced at one time,

284
00:16:06,860 --> 00:16:09,413
there were no California condors in the wild,

285
00:16:10,300 --> 00:16:14,450
hunted, poisoned, and displaced from their habitat.

286
00:16:14,450 --> 00:16:16,730
It was only breeding in captivity

287
00:16:16,730 --> 00:16:18,429
that saved the last few birds.

288
00:16:18,429 --> 00:16:23,429
(soft music)
(birds chirping)

289
00:16:31,380 --> 00:16:35,290
There are many animals that are not classified as extinct,

290
00:16:35,290 --> 00:16:36,847
but are much more at risk of it.

291
00:16:36,847 --> 00:16:39,450
(soft music)

292
00:16:39,450 --> 00:16:42,310
They might be locally abundant, for example,

293
00:16:42,310 --> 00:16:44,780
common in nature reserves,

294
00:16:44,780 --> 00:16:48,070
but because their pockets of habitat are fragmented,

295
00:16:48,070 --> 00:16:49,283
they can't mix.

296
00:16:50,140 --> 00:16:53,070
This makes them much more susceptible to disease,

297
00:16:53,070 --> 00:16:55,550
natural disasters, and other threats

298
00:16:55,550 --> 00:16:57,346
that can wipe out many at once.

299
00:16:57,346 --> 00:16:59,763
(soft music)

300
00:17:02,720 --> 00:17:05,670
Just in terms of numbers of individuals,

301
00:17:05,670 --> 00:17:10,285
we have lost 60% of all virtual bird life since 1970.

302
00:17:10,285 --> 00:17:12,670
(soft music)

303
00:17:12,670 --> 00:17:16,470
In other words, in just one human generation,

304
00:17:16,470 --> 00:17:19,834
more than half of all animals have vanished.

305
00:17:19,834 --> 00:17:22,251
(soft music)

306
00:17:28,900 --> 00:17:31,720
Should we be bothered that some animals are disappearing

307
00:17:32,770 --> 00:17:35,080
are they just unlucky species,

308
00:17:35,080 --> 00:17:36,780
perhaps not strong enough to endure?

309
00:17:36,780 --> 00:17:39,620
(birds chirping)

310
00:17:39,620 --> 00:17:42,343
It does matter because all life is connected.

311
00:17:42,343 --> 00:17:44,760
(soft music)

312
00:17:49,970 --> 00:17:53,730
An ecosystem is like a stack of cards,

313
00:17:53,730 --> 00:17:56,714
pull one out and everything else collapses.

314
00:17:56,714 --> 00:17:59,390
(soft music)

315
00:17:59,390 --> 00:18:01,700
All species of plants and animals

316
00:18:01,700 --> 00:18:03,387
play a role in their environment.

317
00:18:03,387 --> 00:18:05,804
(soft music)

318
00:18:06,640 --> 00:18:09,373
But some, are more influential than others.

319
00:18:10,490 --> 00:18:13,050
They are known as keystone species.

320
00:18:13,050 --> 00:18:15,467
(soft music)

321
00:18:17,120 --> 00:18:18,720
Perhaps the best known example

322
00:18:18,720 --> 00:18:22,060
of the difference one keystone species can make

323
00:18:22,060 --> 00:18:25,242
is the story of wolves in Yellowstone National Park.

324
00:18:25,242 --> 00:18:27,659
(soft music)

325
00:18:30,630 --> 00:18:35,100
Misguided theories on park management in the early 1900s

326
00:18:35,100 --> 00:18:37,620
eradicated the wolf completely.

327
00:18:37,620 --> 00:18:39,663
It became locally extinct.

328
00:18:41,660 --> 00:18:43,240
This was done to protect the herds

329
00:18:43,240 --> 00:18:45,720
of big game animals in the area,

330
00:18:45,720 --> 00:18:47,433
but had the opposite effect.

331
00:18:49,760 --> 00:18:53,793
Without predators, the elk population exploded.

332
00:18:55,100 --> 00:18:58,620
The huge deer overgrazed killing young trees

333
00:18:58,620 --> 00:19:00,110
before they could mature

334
00:19:00,110 --> 00:19:02,957
and wiping out many different grasses and sedges.

335
00:19:02,957 --> 00:19:05,374
(soft music)

336
00:19:08,257 --> 00:19:11,120
Only the fastest growing plants could cope.

337
00:19:11,120 --> 00:19:12,554
The rest disappeared.

338
00:19:12,554 --> 00:19:14,971
(soft music)

339
00:19:18,370 --> 00:19:20,390
Some of the plants played important roles

340
00:19:20,390 --> 00:19:23,440
in anchoring riverbanks, and without them,

341
00:19:23,440 --> 00:19:25,687
the fertile topsoil was washed away.

342
00:19:25,687 --> 00:19:28,900
(soft music)

343
00:19:28,900 --> 00:19:30,450
The land was eroding

344
00:19:30,450 --> 00:19:33,103
as one of the cascading effects of removing wolves.

345
00:19:33,103 --> 00:19:35,780
(soft music)

346
00:19:35,780 --> 00:19:37,780
The changes meant many other species

347
00:19:37,780 --> 00:19:39,967
could no longer find suitable habitats.

348
00:19:39,967 --> 00:19:43,530
(water bubbling)

349
00:19:43,530 --> 00:19:44,441
Beavers,

350
00:19:44,441 --> 00:19:47,200
(water bubbling)

351
00:19:47,200 --> 00:19:48,033
fish,

352
00:19:48,033 --> 00:19:50,531
(water bubbling)

353
00:19:50,531 --> 00:19:52,223
and many songbirds declined.

354
00:19:56,295 --> 00:19:59,045
(birds chirping)

355
00:19:59,960 --> 00:20:02,530
And with nothing to control their numbers,

356
00:20:02,530 --> 00:20:04,882
the elk themselves were in bad shape.

357
00:20:04,882 --> 00:20:07,549
(elk shrieking)

358
00:20:09,400 --> 00:20:11,810
They'd eaten too much of the plant life

359
00:20:11,810 --> 00:20:13,903
and struggled to make it through winter.

360
00:20:19,860 --> 00:20:22,289
The health of the herds was reduced.

361
00:20:22,289 --> 00:20:24,956
(air whooshing)

362
00:20:31,810 --> 00:20:36,090
Thankfully though wolves were exterminated in the USA,

363
00:20:36,090 --> 00:20:38,209
the species was not totally extinct.

364
00:20:38,209 --> 00:20:39,042
(air whooshing)

365
00:20:39,042 --> 00:20:41,740
(soft music)

366
00:20:41,740 --> 00:20:45,250
In the 1990s wolves from Canada were used

367
00:20:45,250 --> 00:20:47,473
to reintroduce the species to Yellowstone.

368
00:20:48,405 --> 00:20:51,238
(wolf whimpering)

369
00:20:53,010 --> 00:20:55,900
They quickly reduced the elk numbers

370
00:20:55,900 --> 00:20:59,200
and it wasn't long before plant and animal diversity

371
00:20:59,200 --> 00:21:01,019
began to return to the region.

372
00:21:01,019 --> 00:21:03,436
(soft music)

373
00:21:21,690 --> 00:21:24,180
While extinctions can be natural,

374
00:21:24,180 --> 00:21:27,010
most of what we are seeing is not,

375
00:21:27,010 --> 00:21:31,215
it's caused by us and in a whole variety of ways.

376
00:21:31,215 --> 00:21:33,632
(soft music)

377
00:21:34,614 --> 00:21:36,170
(rabbit scratching)

378
00:21:36,170 --> 00:21:39,670
The most direct way we get rid of animals is deliberate.

379
00:21:39,670 --> 00:21:42,420
(birds chirping)

380
00:21:43,900 --> 00:21:47,230
The wolves of Yellowstone and the bears of California

381
00:21:47,230 --> 00:21:49,470
were purposefully exterminated

382
00:21:49,470 --> 00:21:51,420
because people didn't want them around.

383
00:21:53,078 --> 00:21:55,495
(soft music)

384
00:22:02,530 --> 00:22:05,400
Predators in particular are often killed

385
00:22:05,400 --> 00:22:07,730
sometimes to protect people,

386
00:22:07,730 --> 00:22:11,750
but mostly to protect livestock and the game birds

387
00:22:11,750 --> 00:22:14,880
and animals that people want to hunt for themselves.

388
00:22:14,880 --> 00:22:17,790
(soft music)
(birds chirping)

389
00:22:17,790 --> 00:22:21,239
Hundreds of predatory mammals and birds like foxes,

390
00:22:21,239 --> 00:22:24,340
(soft music)

391
00:22:24,340 --> 00:22:25,343
Coyotes,

392
00:22:25,343 --> 00:22:27,760
(soft music)

393
00:22:28,750 --> 00:22:29,628
eagles,

394
00:22:29,628 --> 00:22:32,045
(soft music)

395
00:22:33,280 --> 00:22:34,113
and hawks

396
00:22:35,190 --> 00:22:36,736
are poisoned or shot.

397
00:22:36,736 --> 00:22:39,691
(soft music)

398
00:22:39,691 --> 00:22:40,524
(gunshot)

399
00:22:40,524 --> 00:22:43,274
(birds chirping)

400
00:22:46,660 --> 00:22:49,733
Of course, humans have always hunted animals.

401
00:22:51,690 --> 00:22:56,027
In the past, they provided food, tools, and clothing.

402
00:22:56,027 --> 00:22:59,180
(footsteps tapping)

403
00:22:59,180 --> 00:23:02,000
But early humans took only what they needed

404
00:23:02,000 --> 00:23:04,044
and used all parts of the animal.

405
00:23:04,044 --> 00:23:06,794
(fire crackling)

406
00:23:11,418 --> 00:23:14,600
(bird chirping)

407
00:23:14,600 --> 00:23:17,433
(people chanting)

408
00:23:19,750 --> 00:23:23,390
Animals have been and still are killed for food,

409
00:23:23,390 --> 00:23:26,970
clothing, medicine, feathers,

410
00:23:26,970 --> 00:23:30,870
eggs, trophies, souvenirs,

411
00:23:30,870 --> 00:23:33,926
and supposedly for fun in cruise sports.

412
00:23:33,926 --> 00:23:36,259
(loud bang)

413
00:23:38,576 --> 00:23:40,993
(soft music)

414
00:23:47,444 --> 00:23:50,374
(air whooshing)

415
00:23:50,374 --> 00:23:54,199
Whatever humans take, we tend to take too much.

416
00:23:54,199 --> 00:23:57,240
(air whooshing)

417
00:23:57,240 --> 00:24:00,212
And we have a long history of over-exploitation.

418
00:24:00,212 --> 00:24:03,070
(water bubbling)

419
00:24:03,070 --> 00:24:07,890
In the 18 and 1900s, we brought the great whales,

420
00:24:07,890 --> 00:24:09,890
the biggest creatures on the planet

421
00:24:09,890 --> 00:24:11,966
to the very brink of extinction.

422
00:24:11,966 --> 00:24:14,383
(soft music)

423
00:24:15,670 --> 00:24:17,585
Hunting them for oil into meat.

424
00:24:17,585 --> 00:24:20,030
(soft music)

425
00:24:20,030 --> 00:24:22,590
They would protect it from commercial harvest,

426
00:24:22,590 --> 00:24:25,007
(soft music)

427
00:24:26,550 --> 00:24:28,910
but not until they were so rare

428
00:24:28,910 --> 00:24:31,460
that they were no longer profitable to hunt.

429
00:24:31,460 --> 00:24:33,877
(soft music)

430
00:24:43,090 --> 00:24:44,640
Elephants too.

431
00:24:44,640 --> 00:24:47,510
They were hunted purely for their ivory,

432
00:24:47,510 --> 00:24:51,241
much of which was turned into billiard balls and piano keys.

433
00:24:51,241 --> 00:24:53,658
(soft music)

434
00:24:57,230 --> 00:24:59,750
It decimated their numbers,

435
00:24:59,750 --> 00:25:03,250
even though elephants are another keystone species

436
00:25:03,250 --> 00:25:06,190
that's thin out forests and keep the savannas open

437
00:25:06,190 --> 00:25:08,581
to the benefit of thousands of other species.

438
00:25:08,581 --> 00:25:10,998
(soft music)

439
00:25:18,950 --> 00:25:22,583
Trophy hunting has driven hundreds of species into decline.

440
00:25:23,520 --> 00:25:25,910
(gunshot)

441
00:25:25,910 --> 00:25:28,099
Some have been permanently wiped out.

442
00:25:28,099 --> 00:25:32,930
(soft music)
(birds chirping)

443
00:25:32,930 --> 00:25:37,152
While others like tigers and rhinos, hang by a thread.

444
00:25:37,152 --> 00:25:42,152
(soft music)
(birds chirping)

445
00:25:45,580 --> 00:25:47,143
Then there's hunting for food.

446
00:25:48,040 --> 00:25:50,703
The seas are especially over-exploited.

447
00:25:52,170 --> 00:25:56,623
We harvest about 85 million tons of Marine life every year.

448
00:25:57,580 --> 00:26:01,193
For some species, it's just more than they can sustain.

449
00:26:03,860 --> 00:26:07,500
Caught where once the mainstay for many Northern fisheries,

450
00:26:07,500 --> 00:26:09,940
but now in some areas,

451
00:26:09,940 --> 00:26:12,917
they are too rare for it to be viable to hunt them.

452
00:26:12,917 --> 00:26:15,334
(soft music)

453
00:26:17,318 --> 00:26:19,140
(water bubbling)

454
00:26:19,140 --> 00:26:21,590
Sharks too are being massively over-fished

455
00:26:22,470 --> 00:26:26,510
sometimes for meat, sometimes just as by catch,

456
00:26:26,510 --> 00:26:29,868
being caught accidentally in nets set for other species.

457
00:26:29,868 --> 00:26:33,410
(boat engine roaring)

458
00:26:33,410 --> 00:26:36,060
And especially for their fins,

459
00:26:36,060 --> 00:26:40,021
an ingredient in the much prized Asian dish, shark fin soup.

460
00:26:40,021 --> 00:26:42,771
(water bubbling)

461
00:26:44,510 --> 00:26:47,040
Sharks are the wolves of the sea

462
00:26:47,040 --> 00:26:49,560
and where their numbers are diminished,

463
00:26:49,560 --> 00:26:53,434
whole habitats are being damaged as food chains fall apart.

464
00:26:53,434 --> 00:26:56,184
(water bubbling)

465
00:26:58,002 --> 00:27:00,330
(birds chirping)

466
00:27:00,330 --> 00:27:02,393
Nothing is immune to our attacks,

467
00:27:03,830 --> 00:27:04,913
even plants.

468
00:27:06,088 --> 00:27:09,005
(machete rattling)

469
00:27:11,090 --> 00:27:12,990
Brazil nut trees are now rear

470
00:27:12,990 --> 00:27:15,420
because too many seeds are being harvested.

471
00:27:15,420 --> 00:27:17,260
And the forest is being cleared

472
00:27:17,260 --> 00:27:19,618
before the survivors have the chance to mature.

473
00:27:19,618 --> 00:27:22,618
(footsteps tapping)

474
00:27:26,929 --> 00:27:29,620
But even all of this direct exploitation

475
00:27:29,620 --> 00:27:31,830
is not really the biggest problem

476
00:27:31,830 --> 00:27:34,470
that most plants and animals face.

477
00:27:34,470 --> 00:27:36,560
It's ally indirect actions

478
00:27:36,560 --> 00:27:38,452
that are pushing them to the brink.

479
00:27:38,452 --> 00:27:41,150
(air whooshing)
(birds chirping)

480
00:27:41,150 --> 00:27:42,720
One of the things humans have done

481
00:27:42,720 --> 00:27:46,370
in the last few hundred years, both deliberately

482
00:27:46,370 --> 00:27:49,490
and accidentally is transfer animals

483
00:27:49,490 --> 00:27:52,688
and plants into habitats where they don't belong.

484
00:27:52,688 --> 00:27:54,700
(boat engine roaring)

485
00:27:54,700 --> 00:27:58,250
Some of them were stowaways, hitching rides on boats.

486
00:27:58,250 --> 00:28:00,025
As humans explored the world.

487
00:28:00,025 --> 00:28:02,442
(soft music)

488
00:28:03,720 --> 00:28:06,250
This brought rats and mice to islands

489
00:28:06,250 --> 00:28:08,370
where they wreaked havoc with species,

490
00:28:08,370 --> 00:28:10,616
not used to mammalian predators.

491
00:28:10,616 --> 00:28:13,033
(soft music)

492
00:28:15,150 --> 00:28:18,654
Hundreds of birds were wiped out, including the famous Dodo.

493
00:28:18,654 --> 00:28:21,404
(birds chirping)

494
00:28:24,480 --> 00:28:27,720
We also introduce animals on purpose

495
00:28:27,720 --> 00:28:31,220
because we want to take home with us wherever we go,

496
00:28:31,220 --> 00:28:33,100
hunting and eating the same things.

497
00:28:33,100 --> 00:28:35,720
(water bubbling)

498
00:28:35,720 --> 00:28:38,610
So when European settled in Australia,

499
00:28:38,610 --> 00:28:41,570
they took with them rabbits to release into the wild,

500
00:28:41,570 --> 00:28:42,710
to hunt and eat.

501
00:28:42,710 --> 00:28:46,250
(rhythmic music)

502
00:28:46,250 --> 00:28:48,587
Only 24 rabbits were released.

503
00:28:48,587 --> 00:28:53,587
((rhythmic music))

504
00:28:53,620 --> 00:28:55,230
But the speedy breeders

505
00:28:55,230 --> 00:28:57,670
in a land without their normal predators

506
00:28:57,670 --> 00:28:59,890
soon reached plague proportions.

507
00:28:59,890 --> 00:29:02,640
(rhythmic music)

508
00:29:05,290 --> 00:29:09,853
The country was soon overrun with 600 million of them.

509
00:29:10,970 --> 00:29:13,204
It was a devastating change to the continent.

510
00:29:13,204 --> 00:29:15,866
(rhythmic music)

511
00:29:15,866 --> 00:29:19,660
(rhythmic music)
(birds chirping)

512
00:29:19,660 --> 00:29:22,570
Australia had broken away from other land masses

513
00:29:22,570 --> 00:29:24,410
millions of years ago

514
00:29:24,410 --> 00:29:26,895
and its animals and plants were unique.

515
00:29:26,895 --> 00:29:29,312
(soft music)

516
00:29:59,250 --> 00:30:02,560
It was a landscape dominated by Marsupials

517
00:30:02,560 --> 00:30:03,990
slower breeders

518
00:30:03,990 --> 00:30:06,510
that have a lower impact on the fragile

519
00:30:06,510 --> 00:30:08,254
often desert like landscape.

520
00:30:08,254 --> 00:30:11,004
(birds chirping)

521
00:30:14,380 --> 00:30:18,047
The rabbits, bred so much faster that they took over.

522
00:30:18,047 --> 00:30:23,047
(soft music)
(birds chirping)

523
00:30:25,370 --> 00:30:27,497
Stripping the food other species needed.

524
00:30:27,497 --> 00:30:30,680
(soft music)
(birds chirping)

525
00:30:30,680 --> 00:30:32,981
And turning the landscape into a desert.

526
00:30:32,981 --> 00:30:37,981
(soft music)
(birds chirping)

527
00:30:42,640 --> 00:30:45,670
Many Australian species have not recovered

528
00:30:45,670 --> 00:30:47,389
and still teeter on the brink.

529
00:30:47,389 --> 00:30:49,620
(birds chirping)

530
00:30:49,620 --> 00:30:52,950
You might think humans would learn from their mistakes,

531
00:30:52,950 --> 00:30:55,570
but no, they continue to this day.

532
00:30:55,570 --> 00:30:57,716
(birds chirping)

533
00:30:57,716 --> 00:31:00,270
(air whooshing)

534
00:31:00,270 --> 00:31:02,280
There's another side to shipping around

535
00:31:02,280 --> 00:31:06,610
and mistreating wildlife, whether for pets or food,

536
00:31:06,610 --> 00:31:09,200
one that's particularly relevant now.

537
00:31:09,200 --> 00:31:13,436
(soft music)
(people chanting)

538
00:31:13,436 --> 00:31:17,270
All major disease outbreaks, whether it's AIDS,

539
00:31:17,270 --> 00:31:20,050
SARS, swine flu, bird flu,

540
00:31:20,050 --> 00:31:22,200
or COVID-19

541
00:31:22,200 --> 00:31:25,010
have come from inappropriate mistreatment

542
00:31:25,010 --> 00:31:26,903
and movement of wild life.

543
00:31:26,903 --> 00:31:29,320
(soft music)

544
00:31:32,610 --> 00:31:35,260
Another factor that threatens our own health

545
00:31:35,260 --> 00:31:37,890
as well as wildlife is pollution.

546
00:31:37,890 --> 00:31:40,720
(soft music)

547
00:31:40,720 --> 00:31:43,610
Pollution can be accidental like oil spills

548
00:31:43,610 --> 00:31:45,033
that poison Marine life.

549
00:31:46,800 --> 00:31:48,480
Threatening everything from plankton

550
00:31:48,480 --> 00:31:50,148
to turtles and seabirds.

551
00:31:50,148 --> 00:31:55,148
(soft music)
(birds chirping)

552
00:31:55,800 --> 00:31:58,633
But most is churned out constantly by us,

553
00:32:00,290 --> 00:32:03,410
sewage and fertilizers run into the water table

554
00:32:03,410 --> 00:32:07,260
and can poison or over and reach aquatic habitats,

555
00:32:07,260 --> 00:32:08,251
choking them out.

556
00:32:08,251 --> 00:32:10,668
(soft music)

557
00:32:15,340 --> 00:32:19,230
Exhaust fumes from cars and factories chuck out chemicals

558
00:32:19,230 --> 00:32:23,113
like sulfur dioxide and nitrogen oxide into the atmosphere.

559
00:32:24,780 --> 00:32:29,483
They are dissolved by moisture and fall as acid rain.

560
00:32:29,483 --> 00:32:34,233
(soft music)
(raindrops)

561
00:32:41,418 --> 00:32:44,744
The chemical cocktail can damage forests and kill fish.

562
00:32:44,744 --> 00:32:47,161
(soft music)

563
00:32:48,503 --> 00:32:51,740
(air whooshing)

564
00:32:51,740 --> 00:32:55,103
We also love to use chemicals to try and control nature.

565
00:32:55,990 --> 00:32:58,610
We sprayed pesticides, herbicides

566
00:32:58,610 --> 00:33:00,550
and fungicides on our homes,

567
00:33:00,550 --> 00:33:01,396
gardens and especially crops.

568
00:33:01,396 --> 00:33:04,362
(tractor engine roaring)

569
00:33:04,362 --> 00:33:06,140
(bees chirping)

570
00:33:06,140 --> 00:33:09,919
As a result, wild flowers and insects have becoming rare.

571
00:33:09,919 --> 00:33:12,650
(birds chirping)
(bees chirping)

572
00:33:12,650 --> 00:33:15,563
A famous example of that impact is DDT,

573
00:33:17,010 --> 00:33:20,890
organic chlorides heavily used as an insecticide

574
00:33:20,890 --> 00:33:22,713
from the 1950s onwards.

575
00:33:22,713 --> 00:33:24,500
(tractor engine roaring)

576
00:33:24,500 --> 00:33:26,856
They were very effective at killing off insects.

577
00:33:26,856 --> 00:33:29,660
(soft music)

578
00:33:29,660 --> 00:33:33,178
But as a result, songbirds also died off.

579
00:33:33,178 --> 00:33:35,595
(soft music)

580
00:33:37,780 --> 00:33:39,067
In huge numbers.

581
00:33:39,067 --> 00:33:42,143
(soft music)

582
00:33:42,143 --> 00:33:44,540
(birds chirping)

583
00:33:44,540 --> 00:33:46,076
They had another side effect.

584
00:33:46,076 --> 00:33:48,380
(birds chirping)

585
00:33:48,380 --> 00:33:52,150
Bird started laying eggs with abnormally thin shells

586
00:33:52,150 --> 00:33:53,463
that broken the nests.

587
00:33:53,463 --> 00:33:55,970
(soft music)

588
00:33:55,970 --> 00:33:57,850
The numbers of predatory birds,

589
00:33:57,850 --> 00:34:00,658
including the majestic osprey diminished.

590
00:34:00,658 --> 00:34:03,408
(birds chirping)

591
00:34:07,940 --> 00:34:11,300
All poisons climb food chains past

592
00:34:11,300 --> 00:34:13,714
and accumulated from prey to predator.

593
00:34:13,714 --> 00:34:16,400
(plane engine roaring)

594
00:34:16,400 --> 00:34:19,970
DDT was banned in the 70s in many countries,

595
00:34:19,970 --> 00:34:23,010
there was not completely out of circulation

596
00:34:23,010 --> 00:34:27,871
and still persists even in small amounts in human body fat.

597
00:34:27,871 --> 00:34:30,871
(footsteps tapping)

598
00:34:34,960 --> 00:34:38,330
Our use of chemicals threatens our own bodies,

599
00:34:38,330 --> 00:34:40,714
let alone the impact it has on nature.

600
00:34:40,714 --> 00:34:43,131
(soft music)

601
00:34:45,505 --> 00:34:46,910
(water bubbling)

602
00:34:46,910 --> 00:34:48,550
But we are still not done with the list

603
00:34:48,550 --> 00:34:50,513
of ways we are killing off the wild.

604
00:34:52,130 --> 00:34:55,303
Carbon dioxide is a natural part of our atmosphere.

605
00:34:56,410 --> 00:34:59,209
It's the waste or by-product of us breathing,

606
00:34:59,209 --> 00:35:00,920
(people chanting)

607
00:35:00,920 --> 00:35:02,770
but it's levels in the atmosphere

608
00:35:02,770 --> 00:35:06,293
have dramatically increased since the industrial revolution.

609
00:35:07,600 --> 00:35:10,380
The burning of fossil fuels is taking carbon

610
00:35:10,380 --> 00:35:14,513
once locked away in the earth and releasing it into the air.

611
00:35:15,910 --> 00:35:17,800
It is a major greenhouse gas

612
00:35:18,850 --> 00:35:20,901
acting like a blanket around the earth.

613
00:35:20,901 --> 00:35:23,010
(soft music)

614
00:35:23,010 --> 00:35:27,220
Heat from the sun is trapped like being in a greenhouse.

615
00:35:27,220 --> 00:35:29,549
And that is what's driving global warming.

616
00:35:29,549 --> 00:35:32,360
(soft music)

617
00:35:32,360 --> 00:35:33,840
It's possible that the climate

618
00:35:33,840 --> 00:35:36,220
would be slowly changing anyway,

619
00:35:36,220 --> 00:35:39,210
but it's certain that human activities

620
00:35:39,210 --> 00:35:40,909
are escalating it dramatically.

621
00:35:40,909 --> 00:35:44,070
(soft music)

622
00:35:44,070 --> 00:35:47,540
The changes are so fast that it's hard for animals

623
00:35:47,540 --> 00:35:51,515
and plants and even us to adapt in time to cope.

624
00:35:51,515 --> 00:35:53,932
(soft music)

625
00:35:55,970 --> 00:35:57,500
We all know about polar bears

626
00:35:57,500 --> 00:35:59,580
and other creatures from the cold

627
00:35:59,580 --> 00:36:01,830
that are struggling to adapt.

628
00:36:01,830 --> 00:36:04,775
They have become the poster child for climate concerns.

629
00:36:04,775 --> 00:36:07,192
(soft music)

630
00:36:10,550 --> 00:36:12,324
But it affects all life.

631
00:36:12,324 --> 00:36:14,741
(soft music)

632
00:36:18,580 --> 00:36:20,170
Already in Europe,

633
00:36:20,170 --> 00:36:24,380
the populations of flying insects have declined by 75%

634
00:36:24,380 --> 00:36:28,139
in just 30 years, largely due to climate change.

635
00:36:28,139 --> 00:36:30,556
(soft music)

636
00:36:32,165 --> 00:36:33,990
(soft music)
(insects chirping)

637
00:36:33,990 --> 00:36:37,940
Insects are the foundation of most food webs.

638
00:36:37,940 --> 00:36:41,507
So the loss will cascade throughout ecosystems.

639
00:36:41,507 --> 00:36:44,424
(insects chirping)

640
00:36:45,490 --> 00:36:47,120
In the United States,

641
00:36:47,120 --> 00:36:51,383
the number of bees has dropped by half in just 20 years.

642
00:36:52,400 --> 00:36:54,140
The impact of chemical pollutants

643
00:36:54,140 --> 00:36:55,893
on climate change combined.

644
00:36:57,480 --> 00:37:02,103
If we lose bees, we have some serious problems ourselves.

645
00:37:02,950 --> 00:37:07,493
70% of the plants we eat are pollinated by bees.

646
00:37:09,520 --> 00:37:12,643
All of these problems have the potential to be catastrophic,

647
00:37:13,600 --> 00:37:15,533
especially when combined,

648
00:37:17,010 --> 00:37:19,181
but it's probably not the biggest threat.

649
00:37:19,181 --> 00:37:22,000
(soft music)

650
00:37:22,000 --> 00:37:23,420
There is little doubt

651
00:37:23,420 --> 00:37:26,660
that the biggest issue life on our faces

652
00:37:26,660 --> 00:37:28,457
is the sheer number of people.

653
00:37:28,457 --> 00:37:30,229
(ship engine roaring)

654
00:37:30,229 --> 00:37:33,720
(people chanting)

655
00:37:33,720 --> 00:37:38,130
In just one human lifespan, we have gone from 1 billion

656
00:37:38,130 --> 00:37:40,205
to nearly 8 billion people.

657
00:37:40,205 --> 00:37:42,788
(upbeat music)

658
00:37:43,960 --> 00:37:47,312
It's a growth rate that is hard for our planet to sustain.

659
00:37:47,312 --> 00:37:50,260
(upbeat music)

660
00:37:50,260 --> 00:37:52,330
We need too many resources

661
00:37:52,330 --> 00:37:55,160
(upbeat music)

662
00:37:55,160 --> 00:37:57,770
and too much surface area to feed ourselves

663
00:37:57,770 --> 00:37:59,710
and our energy demands

664
00:37:59,710 --> 00:38:01,994
and that doesn't leave much room for anything else.

665
00:38:01,994 --> 00:38:05,237
(soft music)

666
00:38:05,237 --> 00:38:07,904
(air whooshing)

667
00:38:14,612 --> 00:38:17,550
(birds chirping)

668
00:38:17,550 --> 00:38:21,610
Our expansion leads to habitat destruction,

669
00:38:21,610 --> 00:38:23,592
one of the biggest drivers of extinction.

670
00:38:23,592 --> 00:38:27,630
(plane engine roaring)

671
00:38:27,630 --> 00:38:31,083
The problem we all hear most about is the rainforests.

672
00:38:32,180 --> 00:38:34,990
They are one of the worst hit habitats

673
00:38:34,990 --> 00:38:37,384
cut for timber and cleared farming.

674
00:38:37,384 --> 00:38:40,801
(tractor engine roaring)

675
00:38:44,220 --> 00:38:45,513
It's a double loss.

676
00:38:46,350 --> 00:38:47,783
Rainforest soils are poor,

677
00:38:49,760 --> 00:38:52,133
crops quickly absorb all nutrients.

678
00:38:53,200 --> 00:38:55,179
After that, they are useless.

679
00:38:55,179 --> 00:38:57,596
(soft music)

680
00:38:58,980 --> 00:39:01,740
Rainforest doesn't recolonize well.

681
00:39:01,740 --> 00:39:03,569
So the land becomes dry scrub.

682
00:39:03,569 --> 00:39:05,986
(soft music)

683
00:39:13,560 --> 00:39:17,030
Rainforests are the most diverse habitats on the planet

684
00:39:17,030 --> 00:39:19,366
teaming with millions of incredible species.

685
00:39:19,366 --> 00:39:24,366
(soft music)
(birds chirping)

686
00:39:28,140 --> 00:39:31,512
But they are all being lost for short-term farming gains.

687
00:39:31,512 --> 00:39:34,919
(soft music)
(water bubbling)

688
00:39:34,919 --> 00:39:37,550
(soft music)
(birds chirping)

689
00:39:37,550 --> 00:39:41,470
Rainforests coverage is 7% of the land surface,

690
00:39:41,470 --> 00:39:43,676
but how 60% of species.

691
00:39:43,676 --> 00:39:48,676
(soft music)
(birds chirping)

692
00:39:59,742 --> 00:40:03,010
(power saw engine roaring)

693
00:40:03,010 --> 00:40:06,250
An area, the size of 36 football fields

694
00:40:06,250 --> 00:40:08,487
is destroyed every minute.

695
00:40:08,487 --> 00:40:12,070
(power saw engine roaring)

696
00:40:24,544 --> 00:40:27,410
(cow mooing)

697
00:40:27,410 --> 00:40:30,980
Replaced by herds of cattle or plantations of single species

698
00:40:32,330 --> 00:40:35,095
with palm oil being one of the worst culprits,

699
00:40:35,095 --> 00:40:37,540
(people chanting)

700
00:40:37,540 --> 00:40:40,171
few creatures can survive in the monocultures.

701
00:40:40,171 --> 00:40:42,390
(people chanting)

702
00:40:42,390 --> 00:40:46,070
Scientists suggest that by the end of the century,

703
00:40:46,070 --> 00:40:49,310
40% of rainforest species will join the long list

704
00:40:49,310 --> 00:40:50,597
of extinct animals.

705
00:40:50,597 --> 00:40:53,490
(soft music)

706
00:40:53,490 --> 00:40:56,163
Of course, it's not just rainforests.

707
00:40:57,120 --> 00:40:59,084
Woods are cut for timber.

708
00:40:59,084 --> 00:41:02,410
(log rumbles)

709
00:41:02,410 --> 00:41:05,763
Wetlands are drained for farming and development,

710
00:41:07,250 --> 00:41:10,630
mangroves and other fragile coastal habitats are cleared

711
00:41:10,630 --> 00:41:14,308
to make way for waterfront properties and luxury resorts.

712
00:41:14,308 --> 00:41:19,308
(soft music)
(birds chirping)

713
00:41:29,200 --> 00:41:31,673
We are paving over the natural world.

714
00:41:34,840 --> 00:41:38,950
Animals, plants, and their habitats are being fragmented

715
00:41:38,950 --> 00:41:43,460
and isolated, making them much more susceptible

716
00:41:43,460 --> 00:41:47,270
to overgrazing in breeding disease

717
00:41:47,270 --> 00:41:49,261
and ultimately extinction.

718
00:41:49,261 --> 00:41:51,678
(soft music)

719
00:41:52,730 --> 00:41:54,270
How does it affect us?

720
00:41:54,270 --> 00:41:56,687
(soft music)

721
00:41:57,920 --> 00:42:02,160
We lose biodiversity, meaning that ecosystems

722
00:42:02,160 --> 00:42:06,740
no longer function and we need them.

723
00:42:06,740 --> 00:42:10,913
They regulate water cycles and protect us from the elements,

724
00:42:11,970 --> 00:42:16,420
habitats purify our water, absorb pollutants

725
00:42:16,420 --> 00:42:18,520
and lock away carbon.

726
00:42:18,520 --> 00:42:19,940
And the animals in them

727
00:42:19,940 --> 00:42:22,122
are part of the food chain we depend on.

728
00:42:22,122 --> 00:42:24,620
(soft music)

729
00:42:24,620 --> 00:42:27,980
Either directly as food because they pollinate

730
00:42:27,980 --> 00:42:29,959
and fertilize plants that we eat.

731
00:42:29,959 --> 00:42:33,690
(soft music)
(bees chirping)

732
00:42:33,690 --> 00:42:37,430
Losing nature is also damaging our culture.

733
00:42:37,430 --> 00:42:39,580
We cherish the diversity of animals

734
00:42:39,580 --> 00:42:41,863
and plants that share our planet.

735
00:42:42,860 --> 00:42:45,423
It's inspired our history and mythology,

736
00:42:46,550 --> 00:42:48,400
whether we know it or not,

737
00:42:48,400 --> 00:42:50,783
we retain a deep connection to wildlife.

738
00:42:50,783 --> 00:42:52,930
(ducks quacking)

739
00:42:52,930 --> 00:42:55,290
And to be totally selfish,

740
00:42:55,290 --> 00:42:58,020
nature has a direct cash value to us

741
00:42:58,020 --> 00:42:59,803
through crop pollination.

742
00:42:59,803 --> 00:43:01,590
(insect buzzing)

743
00:43:01,590 --> 00:43:02,920
Medicine,

744
00:43:02,920 --> 00:43:04,110
timber,

745
00:43:04,110 --> 00:43:04,947
food.

746
00:43:04,947 --> 00:43:08,000
(soft music)

747
00:43:08,000 --> 00:43:12,460
Water purification, protecting our coastline,

748
00:43:12,460 --> 00:43:15,510
our economy, all of these are in one way

749
00:43:15,510 --> 00:43:18,695
or another dependent on natural resources.

750
00:43:18,695 --> 00:43:20,720
(soft music)

751
00:43:20,720 --> 00:43:23,740
Each time a species becomes extinct,

752
00:43:23,740 --> 00:43:25,893
a natural system unravels a bit.

753
00:43:25,893 --> 00:43:28,310
(soft music)

754
00:43:30,000 --> 00:43:33,000
There have been five mass extinctions before,

755
00:43:33,000 --> 00:43:35,390
but this sixth one is the first

756
00:43:35,390 --> 00:43:37,488
to be caused by a single species.

757
00:43:37,488 --> 00:43:39,905
(soft music)

758
00:43:40,950 --> 00:43:41,861
Us.

759
00:43:41,861 --> 00:43:44,278
(soft music)

760
00:43:48,270 --> 00:43:52,259
And it's one that threatens to end our time on earth too.

761
00:43:52,259 --> 00:43:55,092
(people chanting)

762
00:44:01,527 --> 00:44:02,360
(birds buzzing)

763
00:44:02,360 --> 00:44:04,050
(fire crackling)

764
00:44:04,050 --> 00:44:05,240
Scientists warn us

765
00:44:05,240 --> 00:44:08,350
that we are well into the sixth extinction event

766
00:44:08,350 --> 00:44:11,538
with biodiversity loss happening at a terrifying rate.

767
00:44:11,538 --> 00:44:14,288
(fire crackling)

768
00:44:16,020 --> 00:44:18,910
They also say that it's not too late

769
00:44:18,910 --> 00:44:20,750
to halt the decay of biodiversity

770
00:44:20,750 --> 00:44:23,250
and loss of ecosystem function,

771
00:44:23,250 --> 00:44:26,893
but only if we really act hard and fast.

772
00:44:28,890 --> 00:44:31,530
The window of opportunity to save the world

773
00:44:31,530 --> 00:44:32,893
is rapidly closing.

774
00:44:34,268 --> 00:44:37,185
(iceberg groaning)

775
00:44:44,702 --> 00:44:46,617
But there are plenty of people trying.

776
00:44:46,617 --> 00:44:49,034
(soft music)

777
00:44:52,111 --> 00:44:54,470
All over the world land has been set aside

778
00:44:54,470 --> 00:44:55,813
as nature reserves.

779
00:44:57,193 --> 00:45:02,193
(soft music)
(birds chirping)

780
00:45:04,710 --> 00:45:07,900
Endangered species are being bred in captivity

781
00:45:07,900 --> 00:45:11,010
so that if anything happens to their kind in the wild,

782
00:45:11,010 --> 00:45:13,486
there's a chance they can be re-established.

783
00:45:13,486 --> 00:45:15,903
(soft music)

784
00:45:19,550 --> 00:45:22,380
International conventions meet to decide

785
00:45:22,380 --> 00:45:25,900
which species are in danger and put measures in place

786
00:45:25,900 --> 00:45:27,911
to limit trade and protect them.

787
00:45:27,911 --> 00:45:31,190
(plane engine roaring)

788
00:45:31,190 --> 00:45:34,620
Gene banks and seed banks are like genetic arcs

789
00:45:34,620 --> 00:45:37,276
storing the diversity of the planet for the future.

790
00:45:37,276 --> 00:45:39,693
(soft music)

791
00:45:41,260 --> 00:45:43,403
And all of us can play our part too.

792
00:45:46,830 --> 00:45:48,423
Do you want to save the planet?

793
00:45:50,320 --> 00:45:52,590
Plant some wild flowers in your garden,

794
00:45:52,590 --> 00:45:54,703
school or even window box?

795
00:45:56,760 --> 00:45:59,993
They will attract insects, increasing biodiversity.

796
00:46:01,380 --> 00:46:04,170
The flowers will help boost the numbers of pollinators

797
00:46:04,170 --> 00:46:05,853
like bees and butterflies,

798
00:46:07,370 --> 00:46:09,593
and the insects will attract birds.

799
00:46:10,750 --> 00:46:12,857
You can create a whole ecosystem.

800
00:46:12,857 --> 00:46:15,274
(soft music)

801
00:46:17,260 --> 00:46:21,010
Even tiny pots of plant life are especially important

802
00:46:21,010 --> 00:46:22,670
in the urban environments

803
00:46:22,670 --> 00:46:25,000
that have replaced animals' natural habitats,

804
00:46:25,000 --> 00:46:26,273
all over the world.

805
00:46:26,273 --> 00:46:29,023
(birds chirping)

806
00:46:30,370 --> 00:46:33,120
You can also cut back on consumption,

807
00:46:33,120 --> 00:46:36,269
turn off lights, switch things off when done with them.

808
00:46:36,269 --> 00:46:38,686
(soft music)

809
00:46:41,750 --> 00:46:44,110
Think about where your food comes from.

810
00:46:44,110 --> 00:46:47,173
And if natural habitats are harmed to produce them.

811
00:46:48,280 --> 00:46:50,412
Beef is one of the worst things you can eat.

812
00:46:50,412 --> 00:46:52,240
(cow mooing)

813
00:46:52,240 --> 00:46:55,670
Rainforests are destroyed to create grazing space

814
00:46:55,670 --> 00:46:57,686
and to grow soy to fatten up cattle.

815
00:46:57,686 --> 00:47:00,103
(soft music)

816
00:47:01,650 --> 00:47:04,306
Palm oil is another terribly damaging product.

817
00:47:04,306 --> 00:47:06,300
(fire crackling)

818
00:47:06,300 --> 00:47:09,223
Threatening ages rainforests, and the animals in them.

819
00:47:09,223 --> 00:47:11,640
(soft music)

820
00:47:15,530 --> 00:47:19,210
Eat less fish and check it's from a sustainable stock

821
00:47:19,210 --> 00:47:22,325
and caught in a way that doesn't threaten other species.

822
00:47:22,325 --> 00:47:24,992
(bird chirping)

823
00:47:26,914 --> 00:47:27,747
Check timber or wooden furniture is from a forest

824
00:47:30,470 --> 00:47:31,748
where it will be replanted.

825
00:47:31,748 --> 00:47:36,748
(soft music)
(birds chirping)

826
00:47:39,480 --> 00:47:43,440
Avoid single use plastics and dispose of them carefully

827
00:47:43,440 --> 00:47:45,053
and recycle where possible.

828
00:47:47,970 --> 00:47:50,680
Plastic is a major killer of Marine wildlife,

829
00:47:50,680 --> 00:47:52,343
like turtles and whales.

830
00:47:55,150 --> 00:47:59,000
Even as it falls apart, the fragments are eaten by plankton

831
00:47:59,000 --> 00:48:00,903
and build within the food chain.

832
00:48:02,706 --> 00:48:05,456
(birds chirping)

833
00:48:06,700 --> 00:48:09,334
Everything eats them, even us.

834
00:48:09,334 --> 00:48:12,167
(people chanting)

835
00:48:14,444 --> 00:48:16,300
(bike engine roaring)

836
00:48:16,300 --> 00:48:20,160
We need to commit to decarbonizing our economy

837
00:48:20,160 --> 00:48:22,500
to reduce greenhouse gas emissions,

838
00:48:22,500 --> 00:48:24,367
and switch to renewable energies.

839
00:48:24,367 --> 00:48:27,784
(wind turbine whooshing)

840
00:48:29,154 --> 00:48:31,073
(wind turbine whooshing)
(soft music)

841
00:48:31,073 --> 00:48:33,490
(soft music)

842
00:48:36,760 --> 00:48:40,960
To help reduce carbon emissions, walk more, cycle

843
00:48:40,960 --> 00:48:42,460
and take public transport.

844
00:48:42,460 --> 00:48:44,410
(soft music)

845
00:48:44,410 --> 00:48:46,310
We need to learn from the past

846
00:48:46,310 --> 00:48:49,715
and think sustainably taking only what we need.

847
00:48:49,715 --> 00:48:52,600
(soft music)

848
00:48:52,600 --> 00:48:56,280
These are small and easy changes we can all make

849
00:48:56,280 --> 00:48:58,464
to make the world a better place.

850
00:48:58,464 --> 00:49:00,750
(soft music)

851
00:49:00,750 --> 00:49:02,650
There are currently a million species

852
00:49:02,650 --> 00:49:04,217
racing towards extinction.

853
00:49:04,217 --> 00:49:06,210
(soft music)

854
00:49:06,210 --> 00:49:08,350
The situation can seem hopeless

855
00:49:09,730 --> 00:49:11,950
but humans are a very powerful

856
00:49:11,950 --> 00:49:14,072
and influential force on this planet.

857
00:49:14,072 --> 00:49:15,920
(soft music)

858
00:49:15,920 --> 00:49:19,453
We have caused the decline of wildlife and wild places,

859
00:49:20,650 --> 00:49:23,623
but if we have the power to cause this massive change,

860
00:49:24,630 --> 00:49:28,216
we surely also have the power to correct it.

861
00:49:28,216 --> 00:49:30,633
(soft music)