I have no doubt that the fundamental

source of all our problems,

particularly our governmental problems,

is population growth.

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I love the years of living dangerously

because they tackled one of the main

myths about climate change head-on.

One of the main myths is 
that climate change

is a distant issue. 
It's distant in space;

it's only about the polar bear, 
and not about us,

and it's distant in time;

it's only about future generations, 
not about us.

This is a myth that isn't just among

people who don't think 
climate change is real.

Even many people who do view it as

"Oh it's just you know we'll

deal with it in the future."

The years of living dangerously said,

"No. We are dealing with

it right now whether you like it or not

and let us show you the faces of the

people around the world 
who are dealing with it."

So we're not talking like we were 
50 years ago, 40 years ago.

Oh, like this will be a problem.

It is a problem.

All the systems we have in place:

agriculture, urban environment.

Everything we've set up

has all been predicated on

this very, very stable climate, which

we're now starting to tinker with,

you know, fiddle with the dials
in an uncontrolled way.

The science is looking

at the impact of that on the climate,

the impact on humans, 
the impact on sea level,

the impact on precipitation.

It's gonna be the impact 
on food production.

It's gonna be the impact of

where people live, right?

There is a pretty serious impact.

There's gonna be an 
impact on biodiversity

which, in my opinion has been

bigger than sea level rise, right.

The decay of species.

Unfortunately, it's not the people who are

causing the problems that will be

most affected, so, you know,

American has the highest

commuters per capita.

But it's the people in the developing

natures- regions that will be 
affected most.

So poor old [Curabeth] is already having

saltwater intrusion, inundation,
and sea level rise.

And they're not putting any greenhouse

gas emissions into the atmosphere.

You can imagine that if you're on a

low line pacific island,

well actually a small amount of sea level

makes a massive difference 
to your livelihood.

Ah, combine that with, you know,

a high tide or a storm surge

and then, you know, we get

regions of the world 
that are very vulnerable

to these kind of combined events.

We are very, very vulnerable as a species

to relatively small changes in sea level.

There are countries like Bangladesh,

the Netherlands, and all the Atolls

in the South Pacific,

which would be absolutely devastated

from a sea level rise of 
more than a meter.

Millions and millions of people

are set to be displaced with our

low-end projections of sea level rise.

If we start tracking at higher ends

because of these rapid melting 
of the land ice

over the Greenland and Antarctic regions,

you could have, you know, even more

rapid displacement of populations.

The sea-level rise around about a meter

it's suggested would displace potentially

up to two hundred million people.

It's very clear that if you push

slowly on the climate,

a lot of the things that we have built

hit sudden thresholds.

Either the city is hiding behind the levy

and the water stays just below

the levy during the storm,

or just above.

And that little change

can make a huge difference to whether

your city is livable or not 
the next few weeks.

I think in the tropics, there's where

you're going to see the first real impacts

on people, because the people 
are living right downstream

below the glaciers, and there are

large numbers of people 
living downstream.

So, what's happening to those glaciers

becomes extremely important.

What glaciers do is

they act as sponges basically.

So, in the winter they hold that

snow that falls,

and then they release that snow

in the dry time of the year,

which is typically the summer.

So what glaciers do is 
they tend to even out

the annual precipitation that falls,

and essentially allow areas to carry on

to have agriculture, for example, 
in the summer

when otherwise there'd be areas

that are very, very dry.

If you go to a country like Peru,

seventy percent of the tropical glaciers

on Earth are in Peru,
in the Andes of Peru.

Here you have a country of thirty-four
million people.

Over fifty percent live in the desert

on the West coast of Peru, depending on
rivers that originate

in the glaciers up in the Andes.

Seventy-six percent of their electricity

comes from hydropower,

the water coming from those glaciers.

If you're working in Tibet, there are

forty-six thousand glaciers there.

And you take a river like the Indus river,

it flows through China, through Pakistan,

and through India, all are

nuclear power countries.

All depend on that river for 
its water supplies.

So these are places, geopolitical hotspots

in the future.

I think perhaps the biggest impact is
on agriculture, because the-

if you think of the prairies that

stretch East of the Rockies,

those huge areas are fed by

the rivers that flow from the Rockies.

So you can imagine that if we're trying

to feed a global population, and there are

crops like wheat, for example,

which don't have a high tolerance to

certain high thresholds,
then we could be in serious trouble.

Those that don't have access

to things like air conditioning

or good public health infrastructure.

You know, if you get a heat wave

in those sorts of areas

people get sick, or the elderly

generally get really sick after
a heat wave.

If they don't have
the public infrastructure

to cope with that more people will

unfortunately, be killed.

So when you look at health,

and you look at morbidity 
and mortality rates,

they increase substantially during
heat wave events,

and, in fact, Europe in 2003 there was

somewhere around about

thirty thousand to fifty thousand

excess deaths

due to the heat wave.

Some of my research is in East Africa.

We are seeing climate change impacts

in those places, and they're scary.

You see what happens to people

when the distributions of malaria carrying

mosquitoes expands. It kills them.

It's not an academic issue for me.

This is a deeply ethically based issue.

Climate change in the really short term

is expensive, but not hugely so.

And as the climate change gets bigger,

as we look farther into the future,

the price goes up. The damages go up.

Very crudely, each degree of warming

costs more than the previous degree.

The first degree was almost in the noise

of what we were used to; 
it's not very expensive.

But we've used that one.

And the second degree will cost

a little more. It's moving outside

of your experience, it's starting to
stress things,

and we've committed to that one
very broadly.

The third degree costs more
than the second.

And by the fourth, and the fifth,

now, sea level rise is going to get huge.

We have real problems with crops,

which may be bumping up against

biochemical limits and the ability to

feed ourselves gets 
a little bit worrisome.

And so, by the time you start running

to the third, the fourth, 
the fifth degree,

the cost of damages, the dangers,

go way up. But we're arguing now

about the third degree, 
because we've basically-

We've warmed almost all of the first one,

and we really have committed

to the second one.

There are consequences in terms

of human life for this.

There are consequences in terms

of extinction rates for this.

There are consequences in terms
of ecosystem services.

Every single day that goes by

that we don't begin to address these

problems, the problem gets worse,

more expensive, more immediate,

and in some parts of 
the world has a toll in

in terms of people dying.

And for me this is

just, like, fundamental. 
We don't have time

to muck about with this.

This is not an ivory tower argument.

This is one where 
the consequences are real.

We have to really try
and wake people up

to realize that this is happening,

it's very, very serious, but we

can solve it. But we have to do so

not because, you know, it's gonna
cut the economy,

but because it's the planet

we live on, and it's the people

that we love that are going to be affect-

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