(air whooshing)
Extinction,
(air whooshing)
a daunting and confusing word,
a natural force in nature that sees the end of some species,
creating space for others.
(soft music)
A force so powerful. It wiped out the dinosaurs.
(asteroid striking)
We hear in the news every day
that animal species are getting rarer and rarer.
Some scientists say we are entering a sick extinction.
Unlike anything the world has ever seen before.
(fire crackling)
There can be many causes of extinction
and we have a lot to lean,
but one thing is for sure,
(iceberg groaning)
there is no coming back.
(soft music)
It's easy to be confused about what extinction is,
how it happens and what it means.
(soft music)
In its simplest form,
it's when more members of a species are dying than are born.
Many factors can cause this to happen,
but one thing's for sure it comes to us all.
Extinction is a part of life on earth.
(soft music)
Much of what we know comes from clues buried in the earth.
Faint ghosts of long lost life.
The victims of extinction.
(soft music)
From the fossil record,
we can piece together the Earth's history
and understand the role extinction has played.
(soft music)
90% of all species
that have ever lived on the planet are extinct.
They had their time and now they are gone.
(soft music)
It's natural.
Part of the process of evolution,
one species evolving into another,
or dying out and creating opportunities
for new species to arise.
(soft music)
It's often a slow and steady decline.
As a species is less able
to cope with changing habitat and climate
or the arrival of new competing species
pressure from new predators or the decline of prey.
(soft music)
For whatever reason, their situation changes faster
than they can adapt to it.
And so their numbers begin to drop.
(soft music)
This is known as background extinction rate
and happens naturally like a ticking clock,
a biological baseline.
(soft music)
At a normal pace for every species lost,
another evolves to replace it.
(soft music)
There are exceptions to the rules.
(soft music)
Sometimes something catastrophic happens.
(asteroid roaring)
There have been five major extinction events
during the Earth's history, mostly caused by meteoric events
or bouts of increased volcanic activity.
(volcano rumbling)
(dinosaur tapping)
The fifth event in the sequence known as the big five
is the most famous.
(dinosaurs grunt)
66 million years ago, an asteroid the size of a city
hit the earth on the coast of Mexico,
sending up clouds of debris that blotted out the sun.
(asteroid whooshing)
It famously killed the last of the dinosaurs,
but also took with it at least 75% of lifeforms.
Like all mass extinctions. It was devastating.
(air whooshing)
But also created a land of opportunities for the survivors.
(air whooshing)
Without the huge dinosaurs that dominated the landscape,
the small mammals that lived in their shadows
had the chance to diversify.
(soft music)
It's when our own ancestors really got a foot in the door,
(soft music)
(birds chirping)
by studying the fossil record,
scientists have estimated a background rate,
the natural speed at which species die out
outside of catastrophic events.
And that reveals a problem.
(soft music)
Right now, the current extinction rate
is at least 10 times, and perhaps as much as 10,000 times
faster than it should be.
(soft music)
We're almost certainly in a sixth mass extinction event,
but this one's unlike any the world has ever seen before.
The question is, how much of this new wave of extinction
is because of us?
And what does it mean for the planet and our future on it?
(water roaring)
(soft music)
(air whooshing)
Extinction is a very hard thing to study or measure.
(air whooshing)
(soft music)
We don't even know
how many species we shared this planet with.
(birds chirping)
We know, there are at least 2 million
and estimates suggest perhaps as many as 8 million
other forms of life.
(water bubbling)
New species are discovered all the time.
And some of the new ones are already endangered,
before we even know that they exist.
(birds chirping)
Today, 25,000 plants
and animals are on the brink.
(soft music)
When you break down the statistics,
they're pretty frightening.
(water bubbling)
One third of corals,
(water bubbling)
sharks
and rays
(water bubbling)
and freshwater mussels are endangered.
(water bubbling)
20% of fish,
(water bubbling)
a fifth of all reptiles,
(birds chirping)
a sixth of birds,
(soft music)
and a staggering quarter of all known mammals
are facing extinction.
(soft music)
And nearly 70% of all plant species are threatened.
Considering that they give us oxygen to breathe
and other basis of the food chain.
This is something we should be pretty concerned with.
Even our closest relatives are in danger.
Half of all primates are threatened with extinction.
(baboons grunting) (birds chirping)
Why is it important for us to know.
(frogs croaking)
Take frogs example.
(frogs croaking)
Amphibians are very sensitive
to changes in their environment.
Things like poor water and air quality
can cause them to die off.
(frogs croaking)
(water bubbling)
If they're dying,
it tells us there is something wrong with their habitat.
And today a third of amphibians are facing extinction.
(insects chirping)
(air whooshing)
The Earth's climate goes through natural periods
of cooling and warming.
(soft music)
Not all animals can cope with their habitats getting warmer,
wetter, cooler,
or drier.
The varied climate also brings changes in sea level,
submerged land can rise
linking previously separated land masses.
(soft music)
Allowing animals to travel to new areas
where they might spread disease, hunt
or out-compete native species causing extinction.
(soft music)
And it's not just animals that immigrate.
(soft music)
10,000 years ago at the end of the last ice age
land bridges enable humans
to walk from Asia into North America.
(soft music)
Soon after the continent giant mammals like mammoths,
mastodons and giant armadillos became extinct.
(footsteps tapping) (elephant roars)
(footsteps tapping)
It's likely that the changing climate
was already putting those species under stress.
(elephant roars)
But also very likely that he was hunting pressure
from humans that drove them over the edge.
(footsteps tapping)
(elephant roars)
In other parts of the world, humans were starting to farm
switching from being nomadic hunter gatherers,
to forming permanent settlements and changing habitats
and plants and animals in them to suit their needs.
(birds chirping)
(animal mooing)
(soft music)
The domestication of livestock
and crops has led to a continued trend of reduced diversity.
As farmers have favored monocultures,
single species that they want to harvest.
(soft music)
Domestic animals were bred from wild species that were tamed
and then use to replace the wild species,
which were gradually hunted to extinction.
(soft music)
The majestic aurochs once roamed across Europe and Asia,
the great granddaddy of the domestic cow.
(air whooshing)
Running alongside herds of Tar-Pam,
(birds chirping)
the ancestor of our domestic horse.
(birds chirping)
These beautiful species, so vital to the development
of human farming have been totally extinct
for hundreds of years.
(birds chirping)
These are lookalikes bred back from ancient breeds.
(birds chirping)
(air whooshing)
As shipping technologies improved
global exploration saw the discovery
of new resources to exploit
(air whooshing)
and the transfer of non-native species around the world,
as people try to set up home
on far-flung corners of the globe.
(soft music)
Island species have small populations
and are especially vulnerable.
(soft music)
When people arrived on islands,
a pattern was repeated over and over.
Hunting animals, changing their habitats
and introducing predatory species
that they had no natural defense against.
(air whooshing)
(tortoise chucks)
Many were hard hit, such as the giant tortoise.
(footsteps tapping)
(birds chirping)
In the absence of predators or competition,
the gentle giants have reached huge sizes,
making them desirable sources of meat for sailors.
(soft music)
Their numbers were decimated and most species wiped out.
(soft music)
From the 1800s industry group.
(log rambles)
(seesaw roars)
Ramping up extinction rates
with their consumption and pollution.
(soft music)
There is no doubt this loss of species
is directly tied to us.
(soft music)
Though extinction is final, there are different definitions.
(air whooshing)
For example, species can be locally extinct.
The grizzly bear is the state symbol for California
because when Europeans first arrived,
the bears were abundant.
(soft music)
(bears grumbles)
Grizzly bears still exist in the North of the continent,
but are extinct in California.
(leaves rattling)
When there are too few examples of a species left
to perform a function in an ecosystem,
they are considered functionally extinct.
(soft music)
There are also species that are extinct in the wild.
Although they have been reintroduced at one time,
there were no California condors in the wild,
hunted, poisoned, and displaced from their habitat.
It was only breeding in captivity
that saved the last few birds.
(soft music) (birds chirping)
There are many animals that are not classified as extinct,
but are much more at risk of it.
(soft music)
They might be locally abundant, for example,
common in nature reserves,
but because their pockets of habitat are fragmented,
they can't mix.
This makes them much more susceptible to disease,
natural disasters, and other threats
that can wipe out many at once.
(soft music)
Just in terms of numbers of individuals,
we have lost 60% of all virtual bird life since 1970.
(soft music)
In other words, in just one human generation,
more than half of all animals have vanished.
(soft music)
Should we be bothered that some animals are disappearing
are they just unlucky species,
perhaps not strong enough to endure?
(birds chirping)
It does matter because all life is connected.
(soft music)
An ecosystem is like a stack of cards,
pull one out and everything else collapses.
(soft music)
All species of plants and animals
play a role in their environment.
(soft music)
But some, are more influential than others.
They are known as keystone species.
(soft music)
Perhaps the best known example
of the difference one keystone species can make
is the story of wolves in Yellowstone National Park.
(soft music)
Misguided theories on park management in the early 1900s
eradicated the wolf completely.
It became locally extinct.
This was done to protect the herds
of big game animals in the area,
but had the opposite effect.
Without predators, the elk population exploded.
The huge deer overgrazed killing young trees
before they could mature
and wiping out many different grasses and sedges.
(soft music)
Only the fastest growing plants could cope.
The rest disappeared.
(soft music)
Some of the plants played important roles
in anchoring riverbanks, and without them,
the fertile topsoil was washed away.
(soft music)
The land was eroding
as one of the cascading effects of removing wolves.
(soft music)
The changes meant many other species
could no longer find suitable habitats.
(water bubbling)
Beavers,
(water bubbling)
fish,
(water bubbling)
and many songbirds declined.
(birds chirping)
And with nothing to control their numbers,
the elk themselves were in bad shape.
(elk shrieking)
They'd eaten too much of the plant life
and struggled to make it through winter.
The health of the herds was reduced.
(air whooshing)
Thankfully though wolves were exterminated in the USA,
the species was not totally extinct.
(air whooshing)
(soft music)
In the 1990s wolves from Canada were used
to reintroduce the species to Yellowstone.
(wolf whimpering)
They quickly reduced the elk numbers
and it wasn't long before plant and animal diversity
began to return to the region.
(soft music)
While extinctions can be natural,
most of what we are seeing is not,
it's caused by us and in a whole variety of ways.
(soft music)
(rabbit scratching)
The most direct way we get rid of animals is deliberate.
(birds chirping)
The wolves of Yellowstone and the bears of California
were purposefully exterminated
because people didn't want them around.
(soft music)
Predators in particular are often killed
sometimes to protect people,
but mostly to protect livestock and the game birds
and animals that people want to hunt for themselves.
(soft music) (birds chirping)
Hundreds of predatory mammals and birds like foxes,
(soft music)
Coyotes,
(soft music)
eagles,
(soft music)
and hawks
are poisoned or shot.
(soft music)
(gunshot)
(birds chirping)
Of course, humans have always hunted animals.
In the past, they provided food, tools, and clothing.
(footsteps tapping)
But early humans took only what they needed
and used all parts of the animal.
(fire crackling)
(bird chirping)
(people chanting)
Animals have been and still are killed for food,
clothing, medicine, feathers,
eggs, trophies, souvenirs,
and supposedly for fun in cruise sports.
(loud bang)
(soft music)
(air whooshing)
Whatever humans take, we tend to take too much.
(air whooshing)
And we have a long history of over-exploitation.
(water bubbling)
In the 18 and 1900s, we brought the great whales,
the biggest creatures on the planet
to the very brink of extinction.
(soft music)
Hunting them for oil into meat.
(soft music)
They would protect it from commercial harvest,
(soft music)
but not until they were so rare
that they were no longer profitable to hunt.
(soft music)
Elephants too.
They were hunted purely for their ivory,
much of which was turned into billiard balls and piano keys.
(soft music)
It decimated their numbers,
even though elephants are another keystone species
that's thin out forests and keep the savannas open
to the benefit of thousands of other species.
(soft music)
Trophy hunting has driven hundreds of species into decline.
(gunshot)
Some have been permanently wiped out.
(soft music) (birds chirping)
While others like tigers and rhinos, hang by a thread.
(soft music) (birds chirping)
Then there's hunting for food.
The seas are especially over-exploited.
We harvest about 85 million tons of Marine life every year.
For some species, it's just more than they can sustain.
Caught where once the mainstay for many Northern fisheries,
but now in some areas,
they are too rare for it to be viable to hunt them.
(soft music)
(water bubbling)
Sharks too are being massively over-fished
sometimes for meat, sometimes just as by catch,
being caught accidentally in nets set for other species.
(boat engine roaring)
And especially for their fins,
an ingredient in the much prized Asian dish, shark fin soup.
(water bubbling)
Sharks are the wolves of the sea
and where their numbers are diminished,
whole habitats are being damaged as food chains fall apart.
(water bubbling)
(birds chirping)
Nothing is immune to our attacks,
even plants.
(machete rattling)
Brazil nut trees are now rear
because too many seeds are being harvested.
And the forest is being cleared
before the survivors have the chance to mature.
(footsteps tapping)
But even all of this direct exploitation
is not really the biggest problem
that most plants and animals face.
It's ally indirect actions
that are pushing them to the brink.
(air whooshing) (birds chirping)
One of the things humans have done
in the last few hundred years, both deliberately
and accidentally is transfer animals
and plants into habitats where they don't belong.
(boat engine roaring)
Some of them were stowaways, hitching rides on boats.
As humans explored the world.
(soft music)
This brought rats and mice to islands
where they wreaked havoc with species,
not used to mammalian predators.
(soft music)
Hundreds of birds were wiped out, including the famous Dodo.
(birds chirping)
We also introduce animals on purpose
because we want to take home with us wherever we go,
hunting and eating the same things.
(water bubbling)
So when European settled in Australia,
they took with them rabbits to release into the wild,
to hunt and eat.
(rhythmic music)
Only 24 rabbits were released.
((rhythmic music))
But the speedy breeders
in a land without their normal predators
soon reached plague proportions.
(rhythmic music)
The country was soon overrun with 600 million of them.
It was a devastating change to the continent.
(rhythmic music)
(birds chirping)
Australia had broken away from other land masses
millions of years ago
and its animals and plants were unique.
(soft music)
It was a landscape dominated by Marsupials
slower breeders
that have a lower impact on the fragile
often desert like landscape.
(birds chirping)
The rabbits, bred so much faster that they took over.
(soft music) (birds chirping)
Stripping the food other species needed.
(soft music) (birds chirping)
And turning the landscape into a desert.
(soft music) (birds chirping)
Many Australian species have not recovered
and still teeter on the brink.
(birds chirping)
You might think humans would learn from their mistakes,
but no, they continue to this day.
(birds chirping)
(air whooshing)
There's another side to shipping around
and mistreating wildlife, whether for pets or food,
one that's particularly relevant now.
(soft music) (people chanting)
All major disease outbreaks, whether it's AIDS,
SARS, swine flu, bird flu,
or COVID-19
have come from inappropriate mistreatment
and movement of wild life.
(soft music)
Another factor that threatens our own health
as well as wildlife is pollution.
(soft music)
Pollution can be accidental like oil spills
that poison Marine life.
Threatening everything from plankton
to turtles and seabirds.
(soft music) (birds chirping)
But most is churned out constantly by us,
sewage and fertilizers run into the water table
and can poison or over and reach aquatic habitats,
choking them out.
(soft music)
Exhaust fumes from cars and factories chuck out chemicals
like sulfur dioxide and nitrogen oxide into the atmosphere.
They are dissolved by moisture and fall as acid rain.
(soft music) (raindrops)
The chemical cocktail can damage forests and kill fish.
(soft music)
(air whooshing)
We also love to use chemicals to try and control nature.
We sprayed pesticides, herbicides
and fungicides on our homes,
gardens and especially crops.
(tractor engine roaring)
(bees chirping)
As a result, wild flowers and insects have becoming rare.
(birds chirping) (bees chirping)
A famous example of that impact is DDT,
organic chlorides heavily used as an insecticide
from the 1950s onwards.
(tractor engine roaring)
They were very effective at killing off insects.
(soft music)
But as a result, songbirds also died off.
(soft music)
In huge numbers.
(soft music)
(birds chirping)
They had another side effect.
(birds chirping)
Bird started laying eggs with abnormally thin shells
that broken the nests.
(soft music)
The numbers of predatory birds,
including the majestic osprey diminished.
(birds chirping)
All poisons climb food chains past
and accumulated from prey to predator.
(plane engine roaring)
DDT was banned in the 70s in many countries,
there was not completely out of circulation
and still persists even in small amounts in human body fat.
(footsteps tapping)
Our use of chemicals threatens our own bodies,
let alone the impact it has on nature.
(soft music)
(water bubbling)
But we are still not done with the list
of ways we are killing off the wild.
Carbon dioxide is a natural part of our atmosphere.
It's the waste or by-product of us breathing,
(people chanting)
but it's levels in the atmosphere
have dramatically increased since the industrial revolution.
The burning of fossil fuels is taking carbon
once locked away in the earth and releasing it into the air.
It is a major greenhouse gas
acting like a blanket around the earth.
(soft music)
Heat from the sun is trapped like being in a greenhouse.
And that is what's driving global warming.
(soft music)
It's possible that the climate
would be slowly changing anyway,
but it's certain that human activities
are escalating it dramatically.
(soft music)
The changes are so fast that it's hard for animals
and plants and even us to adapt in time to cope.
(soft music)
We all know about polar bears
and other creatures from the cold
that are struggling to adapt.
They have become the poster child for climate concerns.
(soft music)
But it affects all life.
(soft music)
Already in Europe,
the populations of flying insects have declined by 75%
in just 30 years, largely due to climate change.
(soft music)
(insects chirping)
Insects are the foundation of most food webs.
So the loss will cascade throughout ecosystems.
(insects chirping)
In the United States,
the number of bees has dropped by half in just 20 years.
The impact of chemical pollutants
on climate change combined.
If we lose bees, we have some serious problems ourselves.
70% of the plants we eat are pollinated by bees.
All of these problems have the potential to be catastrophic,
especially when combined,
but it's probably not the biggest threat.
(soft music)
There is little doubt
that the biggest issue life on our faces
is the sheer number of people.
(ship engine roaring)
(people chanting)
In just one human lifespan, we have gone from 1 billion
to nearly 8 billion people.
(upbeat music)
It's a growth rate that is hard for our planet to sustain.
(upbeat music)
We need too many resources
(upbeat music)
and too much surface area to feed ourselves
and our energy demands
and that doesn't leave much room for anything else.
(soft music)
(air whooshing)
(birds chirping)
Our expansion leads to habitat destruction,
one of the biggest drivers of extinction.
(plane engine roaring)
The problem we all hear most about is the rainforests.
They are one of the worst hit habitats
cut for timber and cleared farming.
(tractor engine roaring)
It's a double loss.
Rainforest soils are poor,
crops quickly absorb all nutrients.
After that, they are useless.
(soft music)
Rainforest doesn't recolonize well.
So the land becomes dry scrub.
(soft music)
Rainforests are the most diverse habitats on the planet
teaming with millions of incredible species.
(soft music) (birds chirping)
But they are all being lost for short-term farming gains.
(soft music) (water bubbling)
(soft music) (birds chirping)
Rainforests coverage is 7% of the land surface,
but how 60% of species.
(soft music) (birds chirping)
(power saw engine roaring)
An area, the size of 36 football fields
is destroyed every minute.
(power saw engine roaring)
(cow mooing)
Replaced by herds of cattle or plantations of single species
with palm oil being one of the worst culprits,
(people chanting)
few creatures can survive in the monocultures.
(people chanting)
Scientists suggest that by the end of the century,
40% of rainforest species will join the long list
of extinct animals.
(soft music)
Of course, it's not just rainforests.
Woods are cut for timber.
(log rumbles)
Wetlands are drained for farming and development,
mangroves and other fragile coastal habitats are cleared
to make way for waterfront properties and luxury resorts.
(soft music) (birds chirping)
We are paving over the natural world.
Animals, plants, and their habitats are being fragmented
and isolated, making them much more susceptible
to overgrazing in breeding disease
and ultimately extinction.
(soft music)
How does it affect us?
(soft music)
We lose biodiversity, meaning that ecosystems
no longer function and we need them.
They regulate water cycles and protect us from the elements,
habitats purify our water, absorb pollutants
and lock away carbon.
And the animals in them
are part of the food chain we depend on.
(soft music)
Either directly as food because they pollinate
and fertilize plants that we eat.
(soft music) (bees chirping)
Losing nature is also damaging our culture.
We cherish the diversity of animals
and plants that share our planet.
It's inspired our history and mythology,
whether we know it or not,
we retain a deep connection to wildlife.
(ducks quacking)
And to be totally selfish,
nature has a direct cash value to us
through crop pollination.
(insect buzzing)
Medicine,
timber,
food.
(soft music)
Water purification, protecting our coastline,
our economy, all of these are in one way
or another dependent on natural resources.
(soft music)
Each time a species becomes extinct,
a natural system unravels a bit.
(soft music)
There have been five mass extinctions before,
but this sixth one is the first
to be caused by a single species.
(soft music)
Us.
(soft music)
And it's one that threatens to end our time on earth too.
(people chanting)
(birds buzzing)
(fire crackling)
Scientists warn us
that we are well into the sixth extinction event
with biodiversity loss happening at a terrifying rate.
(fire crackling)
They also say that it's not too late
to halt the decay of biodiversity
and loss of ecosystem function,
but only if we really act hard and fast.
The window of opportunity to save the world
is rapidly closing.
(iceberg groaning)
But there are plenty of people trying.
(soft music)
All over the world land has been set aside
as nature reserves.
(soft music) (birds chirping)
Endangered species are being bred in captivity
so that if anything happens to their kind in the wild,
there's a chance they can be re-established.
(soft music)
International conventions meet to decide
which species are in danger and put measures in place
to limit trade and protect them.
(plane engine roaring)
Gene banks and seed banks are like genetic arcs
storing the diversity of the planet for the future.
(soft music)
And all of us can play our part too.
Do you want to save the planet?
Plant some wild flowers in your garden,
school or even window box?
They will attract insects, increasing biodiversity.
The flowers will help boost the numbers of pollinators
like bees and butterflies,
and the insects will attract birds.
You can create a whole ecosystem.
(soft music)
Even tiny pots of plant life are especially important
in the urban environments
that have replaced animals' natural habitats,
all over the world.
(birds chirping)
You can also cut back on consumption,
turn off lights, switch things off when done with them.
(soft music)
Think about where your food comes from.
And if natural habitats are harmed to produce them.
Beef is one of the worst things you can eat.
(cow mooing)
Rainforests are destroyed to create grazing space
and to grow soy to fatten up cattle.
(soft music)
Palm oil is another terribly damaging product.
(fire crackling)
Threatening ages rainforests, and the animals in them.
(soft music)
Eat less fish and check it's from a sustainable stock
and caught in a way that doesn't threaten other species.
(bird chirping)
Check timber or wooden furniture is from a forest
where it will be replanted.
(soft music) (birds chirping)
Avoid single use plastics and dispose of them carefully
and recycle where possible.
Plastic is a major killer of Marine wildlife,
like turtles and whales.
Even as it falls apart, the fragments are eaten by plankton
and build within the food chain.
(birds chirping)
Everything eats them, even us.
(people chanting)
(bike engine roaring)
We need to commit to decarbonizing our economy
to reduce greenhouse gas emissions,
and switch to renewable energies.
(wind turbine whooshing)
(soft music)
To help reduce carbon emissions, walk more, cycle
and take public transport.
(soft music)
We need to learn from the past
and think sustainably taking only what we need.
(soft music)
These are small and easy changes we can all make
to make the world a better place.
(soft music)
There are currently a million species
racing towards extinction.
(soft music)
The situation can seem hopeless
but humans are a very powerful
and influential force on this planet.
(soft music)
We have caused the decline of wildlife and wild places,
but if we have the power to cause this massive change,
we surely also have the power to correct it.
(soft music)