An Inconvenient Truth Page #6

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on the tips

of their constituents' tongues,

it's easy for them to ignore it.

To say, "Well, we'll deal

with that tomorrow."

So the same phenomena of changing

all these patterns

is also affecting the seasons.

Here is a study from the Netherlands.

The peak arrival date for migratory birds

and their chicks hatched

on June the 3rd.

Just at the time when the caterpillars

were coming out.

Nature's plan.

But 20 years of warming later,

the caterpillars peaked

two weeks earlier,

and the chicks tried to catch up with it,

but they couldn't.

And so, they're in trouble.

And there are millions

of ecological niches

that are affected by global warming

in just this way.

This is the number of days with frost

in Southern Switzerland

over the last 100 years.

It has gone down rapidly.

But now watch this.

This is the number

of invasive exotic species

that have rushed in to fill the new

ecological niches that are opening up.

That's happening here

in the United States, too.

You've heard

of the pine beetle problem?

Those pine beetles used to be killed

by the cold winters,

but there are fewer days of frost,

and so the pine trees are

being devastated.

This is part of 14 million acres

of spruce trees in Alaska

that have been killed by bark beetles.

The exact same phenomenon.

There are cities that were founded

because they were just above

the mosquito line.

Nairobi is one, Harare is another.

There are plenty of others.

Now the mosquitoes, with warming,

are climbing to higher altitudes.

There are a lot of vectors for infectious

diseases that are worrisome to us

that are also expanding their range.

Not only mosquitoes,

but all of these others as well.

And we've had 30 so-called

new diseases

that have emerged

just in the last quarter century.

And a lot of them, like SARS, have

caused tremendous problems.

The resistant forms of tuberculosis.

There are others.

And there's been a re-emergence

of some diseases

that were once under control.

The avian flu, of course,

quite a serious matter, as you know.

West Nile Virus.

It came to the eastern shore

of Maryland in 1999.

Two years later,

it was across the Mississippi.

And two years after that,

it had spread across the continent.

But these are very troubling signs.

Coral reefs all over the world,

because of global warming

and other factors,

are bleaching and they end up like this.

And all the fish species

that depend on the coral reefs

are also in jeopardy as a result.

Overall, species loss is now occurring

at a rate 1,000 times greater

than the natural background rate.

This brings me to the second canary

in the coal mine.

Antarctica.

The largest mass of ice on the planet

by far.

A friend of mine said in 1978,

"If you see the breakup of ice shelves

along the Antarctic peninsula,

"watch out

"because that should be seen

as an alarm bell for global warming."

And actually, if you look

at the peninsula up close,

every place where you see

one of these green blotches here

is an ice shelf larger

than the state of Rhode Island

that has broken up

just in the last 15 to 20 years.

I want to focus on just one of them.

It's called Larsen B.

I want you to look

at these black pools here.

It makes it seem almost

as if we're looking through the ice

to the ocean beneath.

But that's an illusion.

This is melting water

that forms in pools,

and if you were flying over it

in a helicopter,

you'd see it's 700 feet tall.

They are so majestic, so massive.

In the distance are the mountains

and just before the mountains

is the shelf of the continent, there.

This is floating ice,

and there's land-based ice

on the down slope of those mountains.

From here to the mountains

is about 20 to 25 miles.

Now they thought this would be

stable for at least 100 years,

even with global warming.

The scientists who study

these ice shelves

were absolutely astonished

when they were looking

at these images.

Starting on January 31, 2002

in a period of 35 days

this ice shelf completely disappeared.

They could not figure out how

in the world this happened so rapidly.

And they went back to try to figure out

where they'd gone wrong.

And that's when they focused

on those pools of melting water.

But even before they could figure out

what had happened there,

something else started going wrong.

When the floating sea-based ice

cracked up,

it no longer held back

the ice on the land,

and the land-based ice

then started falling into the ocean.

It was like letting the cork

out of a bottle.

And there's a difference between

floating ice and land-based ice.

That's like the difference between

an ice cube floating in a glass of water,

which when it melts doesn't raise

the level of water in the glass,

and a cube that's sitting atop

a stack of ice cubes

which melts and flows over the edge.

That's why the citizens

of these Pacific nations

have all had to evacuate

to New Zealand.

But I want to focus on West Antarctica

because it illustrates two factors about

land-based ice and sea-based ice.

It's a little of both.

It's propped up on tops of islands,

but the ocean comes up underneath it.

So as the ocean gets warmer,

it has an impact on it.

If this were to go,

sea level worldwide

would go up 20 feet.

They've measured disturbing changes

on the underside of this ice sheet.

It's considered relatively

more stable, however,

than another big body of ice

that's roughly the same size.

Greenland would also raise sea level

almost 20 feet

if it went.

A friend of mine just brought back

some pictures

of what's going on on Greenland

right now.

Dramatic changes.

These are the same kinds of pools

that formed here,

on this ice shelf in Antarctica.

And the scientists thought

that when that water seeped back

into the ice, it would just refreeze.

But they found out

that actually what happens

is that it just keeps on going.

It tunnels to the bottom

and makes the ice like Swiss cheese,

sort of like termites.

This shows what happens

to the crevasses,

and when lakes form,

they create what are called moulins.

The water goes down to the bottom

and it lubricates

where the ice meets the bedrock.

See these people here for scale.

This is not on the edge of Greenland,

this is in the middle of the ice mass.

This is a massive rushing torrent

of fresh melt water

tunneling straight down

through the Greenland ice

to the bedrock below.

Now, to some extent,

there has always been seasonal melting

and moulins have formed in the past,

but not like now.

In 1992, they measured

this amount of melting in Greenland.

Ten years later, this is what happened.

And here is the melting from 2005.

Tony Blair's scientific advisor

has said that

because of what's happening

in Greenland right now,

the maps of the world will have

to be redrawn.

If Greenland broke up and melted,

or if half of Greenland

and half of West Antarctica

broke up and melted,

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