- [Narrator] We're talking about why
biodiversity is important specifically to us as humans
in the form of ecosystem services.
Given that we'll lose about 20%
of the present species richness by the middle of the century
it's crucial to ask why that should matter to any of us.
Should be worried about that loss?
And why do so many of us care so much about it already.
There are three main ways
in which biodiversity is crucial to humans.
The first is by direct services,
the second is by indirect services,
and the third is the aesthetic or ethical effect.
We get so many things directly from biodiversity
on this planet, food, clothing, housing,
transportation, many medicines and medical supplies,
and even energy in some cases.
These things are derived directly from various ecosystems.
Food goes without saying, all of our major food types,
as diverse as they might be,
originated in diverse ecosystems.
Turns out, that they're a wild types of tomatoes
still growing in Peru.
These Peruvian tomatoes are a different species
from the kind of tomato we typically eat
and hold some of the genetic diversity within them.
When bred with some of the tomatoes that we're using
as our own food now, the yield from the hybrid tomatoes
can go up almost as much as 50%.
And, we wouldn't have that productivity
if we'd let that wild type of Peruvian tomato go extinct.
If we didn't have that as part of
the biodiversity out there today,
there's no way that we would have access
to that genetic diversity.
Another direct service provided by biodiversity is shelter.
Originally, we built housing out of all kinds
of biological materials and even today,
we're still building houses out of trees.
What about medicine?
Almost all the medicines that humankind has developed
have come directly from studying the way
that organisms live in their environment,
how they interact and the chemicals that they use
during those interactions.
The rosy periwinkle is a very famous example
of a plant that grows in some
very secluded environments in Madagascar.
And it turns out that this plant produces
a couple of very interesting chemicals
that are now used to treat childhood leukemia.
Again, we wouldn't have those medicines
if the rosy periwinkle had gone extinct.
Some of the more interesting things
that I think people forget about
when thinking about the value biodiversity
fall under the category of indirect services
that are delivered to us by healthy ecosystems.
If you think about mangrove swamps
which hare these fantastic places
along the coastal margins of some tropical countries
where specific types of trees,
trees called mangroves grow.
Mangroves can grow in salt water,
so they form a semi-marine forest
at the edge between land and sea.
There are many species of mangrove trees
and they're all really tough, resilient plants
that provide tremendous services to us
and to the natural environment.
They protect the coastline from wave action
and erosion, they're nurseries for all kinds
of different types of organisms,
and some of these are very important food types for us.
Unfortunately, in certain parts of the world
people are destroying the mangroves
in order to make shrimp fisheries.
They remove the mangroves and set up shrimp farms
with the idea that they're adding economic value
to that part of the coastline
by putting in a shrimp farm
that's going to produce a commercially viable product.
But if you look at a graph of the value of these things
then value of the shrimp farm
is really only one third, maybe even only one quarter
of the value of the original, undisturbed mangrove swamp
because of the protection that the mangroves give
against storms and erosion
and the food sources they produce such as fish.
You can actually attach a dollar value to these things
which is sometimes the only way
that people really come to grips with ecosystem value.
It's the only way that people really understand
the value of ecosystem services to humanity.
Economic value of intact biodiversity
has also been determined for ecosystems
far from mangrove swamps, much closer to home.
Some years ago, a large city on the east coast,
which shall remain nameless, except that it's New York,
had an issue with the quality of its source water.
There are rivers feeding into the New York City area
and the sources of that water were being compromised
by pollution and environmental degradation
to the point where biodiversity
was being lost in some of those areas.
So, city officials had a question in front of them,
how do we deal in a cost effective way
with this problem of declining quality of our water.
It turns out that to build treatment plants
to deal with cleaning the water up
was gonna cost somewhere in the neighborhood
of $6 billion just to build the treatment plants.
Then another $300 million per year
to maintain those plants
and make sure that they were doing the things
they were supposed to by removing the harmful chemicals
that were being introduced
through environmental degradation upstream.
Then they looked at what it was gonna cost
to clean up and restore the environments
to make sure that the ecosystems
and the biodiversity in those ecosystems
were maintained to the point where they were doing
what they would naturally do
by removing chemicals from the water,
basically filtering it through wetland habitat.
Wetlands are tremendous, tremendous places
for the recycling of dangerous chemicals
and for the removal of chemicals from water
and for clarifying and cleaning water.
The cost for this restoration
was gonna be about $1 billion, spread over 10 years.
Much, much lower costs.
So the answer was pretty clear,
you're gonna go and spend
that billion dollars over 10 years.
Not only do you enhance the quality
of the water in a very cost effective way
but you do something else, too.
And that addresses the third and final aspect
of biodiversity value.
The ethical and aesthetic services
or value provided by biodiversity.
These services may in fact be, in some ways,
the most important ones.
Sure, we can attach dollar values
to the direct and indirect costs
of a decline in biodiversity
and the decline environmental services
and ecosystem services but the ethical
and aesthetic value is something
that's very, very difficult to put a price on.
You might say, okay, well, it costs so much
to go visit a park or you might enjoy the views so much
that you'll put a quarter into the telescope
and soak in that environment
but that's not really what we're talking about.
The value here comes in what we leave for the future.
A drop in biodiversity, removal of biodiversity,
the extinction of species,
those are things that we can't repair.
Lost biodiversity is something we cannot bring back.
So our children are gonna inherit a depleted world.
The ethical and aesthetic quality
of the environments that they're going to experience
in their future, is gonna be decreased.
How do you put a dollar value on that?
We are the stewards of the environment
but we are also the major influence
on environmental quality and certainly
on ecosystem function these days
through our activities that result in pollution,
over fishing, habitat destruction,
loss of certain species from the environment.
No one wants a world that's filled
with nothing but wheat, corn, dandelions,
some cows and us.
That's a very simple ecosystem
that's fraught with future difficulty and instability.
If you reduce biodiversity to the point where
the loss of species in the ecological food web
causes an ecological collapse of that system,
we won't be just standing by watching that collapse,
we're going to be part of it.
Clearly, biodiversity ecosystem
are great places to live and to visit.
There's much to see and make you feel happy,
restful, appreciative, full of awe,
reminded of what a remarkable and unique plant this is.
After all, it's ours.
I think there's a deeper sort of
societal psychology at work here.
And it behooves us to pay attention
not just to the economically measured
direct and indirect services and benefits
provided by diversity rich, healthy ecosystems.
But also to the ethical and aesthetic value
of those amazing environments
that are the inheritance we will leave
for future generations.