What if a small cut like this could kill you?
It could have – once upon a time.
Now we have penicillin,
an antibiotic that's saved countless lives.
Like many other drugs used to treat malaria, pain and cancer...
Penicillin was made using substances that come from nature.
But we're losing plants, animals and other species
way too quickly.
It's not only destroying our chances
to find more revolutionary drugs.
It's also wrecking the ecosystems
that keep us healthy in the first place.
So by killing biodiversity, are we also putting our lives at risk?
It's 1928 – and world-famous scientist
– and slob – Alexander Fleming finds mold
growing on bacteria-filled petri dishes he hasn't cleaned up.
Amazingly, the area around the mold is free of bacteria.
The fungus killed them.
The discovery paved the way for modern antibiotics,
and it came from the natural world.
Biodiversity –
the plants, animals and other elements that make up nature –
is behind many more drugs than you may think.
Around 70% of cancer medications alone
are based on natural substances.
"We have medications for heart disease
coming from the foxglove.
We have medications for cancer
from the yew tree and from the mayapple."
That's Cassandra Quave –
she's an ethnobotanist and wrote a book
called "The Plant Hunter".
"We're looking for new molecules from nature
inspired by those medicines that have been used in the past
and continue to be used
by people living under different paradigms of medical traditions
around the world."
People all over the world have been using nature directly
to heal themselves for thousands of years.
There's latex from fig trees
to treat intestinal parasites in the Amazon
and neem oil used to treat skin disorders in India.
An estimated four billion people
still rely primarily on natural medicines.
"This is not a thing of the past.
This is happening right now all around the world."
But using natural remedies and nature derived medications
is becoming more and more difficult.
And that's because we're quickly losing biodiversity.
The International Union for Conservation of Nature
has assessed more than 150,000 species as part of its Red List,
which tracks the state of biodiversity.
Over a quarter are threatened with extinction.
Animals and other species are disappearing
tens to hundreds of times faster
than at any other time in history,
according to some estimates.
Experts say the biodiversity crisis could be a bigger threat
than climate change.
And the problem...
is us.
"The two things
that threaten biodiversity the most at the moment
are overharvesting and land conversion."
That's EJ Milner-Gulland,
professor of biodiversity at Oxford University.
"And that's not just clearance of land for livestock to graze,
it's clearance of land for food, for livestock to eat
and clearance of the oceans, I should also say for food."
We're chopping down forests, overfishing our oceans.
We're heating the climate, introducing invasive species
and polluting the planet.
In short, we're messing with the intricate balance
between different species in ecosystems –
where a rich biodiversity of different plants and animals
depend on each other for their survival.
A healthy ecosystem is like this Jenga tower –
stable.
But let's say animals or plants start to die off
within the ecosystem one by one.
To begin with, it's not a huge deal.
The tower is still standing.
But slowly, it becomes more and more unstable.
Until eventually, the tower – our ecosystem –
topples altogether.
In other words, all of the species within it could disappear.
We need nature's ecosystems to be healthy and working.
Not only do they provide us the medicine we need
when we're sick.
They also keep us healthy in the first place.
Just to give a few examples:
Trees and shrubs clean our air
by absorbing harmful substances.
Outside air pollution kills four million people every year.
A Boston University study found that up to 38,000 deaths
could have been prevented in the largest US cities alone,
if there had been more greenery.
Then there's soil.
The microbes in it provide the nutrients to grow
around 95 percent of our food, according to the UN.
And there's wetlands that remove
harmful pollutants from the water.
Entire cities rely on this.
Like Kolkata in India.
Around 750 million tonnes of sewage and wastewater
are pumped into the wetlands on the Eastern border of the city.
And there, the waste is purified
and used for fish food and to grow vegetables.
"There are the services that natural ecosystems provide
and as a result of those services,
natural systems support human health."
Peninah Murage researches the links
between health and the environment
at the London School of Hygiene and Tropical Medicine.
"A lot of the things that nature does for us, it does for free.
Because it does it for free, we don't really value it."
Although there have been attempts.
The Boston Consulting Group estimates
that ecosystem services are worth
around 140 trillion euros every year – about twice global GDP.
Our use of natural resources is, at least in part,
the reason why over the past 200 years,
average life expectancy for humans all over the world
has increased.
"We've been getting healthier and healthier,
more and more affluent. So a reduction in poverty.
Our population has increased tremendously.
We've been able to do that by tapping into natural resources.
But we're pushing nature too far –
we are using more of its resources
than the Earth can regenerate.
And by destroying biodiversity,
we are also making ourselves more vulnerable
to new health threats.
Scientists who have studied the COVID-19 virus say
it most likely came from animals originally
and jumped to humans.
This is known as a zoonotic disease.
Ebola, influenza, and HIV are other examples of this.
Things like chopping down forests and hunting –
so everything where humans and wildlife are in close contact –
increase the risk of these spreading.
"Our health, our wellbeing can no longer continue to improve
and it's going to get to a point where
we've destroyed the environment to such a state
that it can only go downward.
So what can we do
to save biodiversity and keep humans healthy?
Clearly, there's no one solution.
But there are different ways to protect,
regenerate and sustainably manage ecosystems.
For example, rewilding – or rebuilding ecosystems –
reintroducing species
that have been lost from particular regions.
You can find out more
about rewilding vultures in Eastern Europe in our Planet A video.
Agroforestry is another example.
So instead of completely razing land for agriculture,
using the native trees and shrubs to help grow crops.
"It turns out that trees are really good at increasing soil fertility.
They're like organic natural fertilizers."
Or we could simply leave forests standing –
and plant more trees.
They are home to around 80 percent of land-based biodiversity,
provide clean air and water and each tree sucks in CO2.
Things are moving in the right direction.
Global governments have committed to protect
30 percent of land and oceans
and restore degraded natural areas by 2030.
But these promises need to be turned into action.
"If there's anything that I've learned in this journey,
it's really that human health and planetary health
are intricately intertwined.
You can't have one without the other."
If we look after nature, it has the capacity to help us even more.
Because there are species like sea sponges, for example,
that are already being studied
and could provide more drugs to treat cancer.
And scientists are also looking to plant species
to treat the bacteria now resistant to the antibiotics,
like Penicillin, that we discovered almost a century ago.
It's an absurd race against time:
Finding the cure before species go extinct.
"Biodiversity is the fabric
that holds our life support together on our planet.
And if we didn't have living wild nature, it would be, you know,
much harder or impossible to live on this planet.
Without biodiversity,
humans could be the next threatened species.
And even if it doesn't come to that:
Wouldn't you just prefer
to live in a world full of beauty and diversity?
How important is the natural world to you and your health?
Let us know in the comments below.
And don't forget to subscribe.
We release a new video every Friday.