National Geographic: Six Degrees Could Change the World Page #2

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Now global warming

is measured in decades,

even years.

It means scores of species

won't be able to keep up.

Warming at this speed could send

us into uncharted territory,

like nothing we've experienced

in the history of life on Earth.

Global warming started

with our insatiable appetite for energy.

Every switch we flip, every plug,

every button we push

to turn something on,

inevitably leads back

to a place like this.

Nearly 90 percent of the world's energy

starts as a fossil fuel:

Coal, oil, natural gas.

These three fuels combined

are the single largest source

of CO2 emissions pouring

into the atmosphere.

If the world warms by two degrees,

some changes to the biosphere

are no longer gradual.

Greenland's glaciers are disappearing.

So much ice has melted,

polar bears struggle to survive.

Insects migrate

in strange new directions.

As a temperate climate

moves north in the U.S.,

pine beetles kill off

the white bark forests,

a grizzly bear's key source

of food in the fall.

New forests take root

in Canada's melting tundra.

The Pacific islands

of Tuvalu are lost

beneath the rising tides

of global warming.

This could be our world

plus-two degrees.

At two degrees of warming,

the impacts in the marine ecosystem

are going to be much more severe.

The oceans are the planet's

largest "carbon sink,"

nature's primary mechanism

for absorbing CO2

out of the atmosphere.

But lately there are indications

these systems are breaking down.

Under normal conditions,

tiny sea creatures like forams

and coccolithophores

absorb carbon out of the water

and use it to build

their shells and skeletons.

But there is a tipping point,

when too much CO2 in the oceans

turns the water

increasingly acidic.

Acidification dissolves

the creatures' shells and skeletons

and prevents them from absorbing

more CO2 out of the water

to build new ones.

Some of these tiny animals

at the bottom of the food chain

measure only one millimeter.

But the fate of all sea creatures,

of all shapes and sizes,

larger and larger,

hangs in the balance.

Alter the ocean's chemistry,

and nature's primary mechanism

for controlling the climate

begins to break down.

You lose a coral reef,

you lose perhaps 500,000 species.

You lose those little coccolithophores,

these little algae,

and you start to lose things

that are very important

to life on this planet.

We're losing some of the most vital

elements of the way the world works.

And that's got us all concerned.

Scientists half a world away

share those concerns.

They're investigating global warming

at the climate's opposite extreme.

It took nature 150,000 years

to make the great Greenland ice sheet

that's now melting into the sea

faster than at any time in history.

As it disappears, rising oceans

will flood coastal cities

around the world.

Greenland's Jakobshavn Glacier

is the fastest moving ice field

on the planet,

more than 40 meters per day,

melting into the sea

twice as fast as a decade ago.

Rising temperatures

are transforming

one of the Earth's harshest climates,

disrupting the way people have lived

in Greenland for hundreds of years.

For as long as anyone can remember,

sled dogs have been

a symbol of wealth here

and a necessity for survival,

especially for hunting

across the winter sea ice.

When the winter ice started thinning,

dogs became an expense

most islanders couldn't afford.

In this town of 4,500 people,

there are 4,000 dogs,

with very little to do these days.

Many are starving.

Some are being put down.

Marit Holm is one of Greenland's

five veterinarians.

As she patrols the town of Ilulissat,

she sees the impact of climate change

in every sled dog

without a sled to pull.

So, what I do, I drive

around and look after the dogs.

The dogs are hungry,

so I have to be a little bit careful

not to get bitten.

And when the dogs are hungry,

they are a little bit more dangerous

to people and kids walking around.

It doesn't seem to be sick.

He's very skinny.

So I have to try to find out

who's the owner

and talk to him.

These animals were

once in peak physical condition.

They served a vital purpose

in their owners' lives.

That's a thing of the past,

and we don't see

any young people who take

some dogs and live

as a fisherman and a hunter.

Dogs have been

in Finn Sistall's family

as long as he can remember.

He finally gave up his team of 19

just in the last few years.

In the winter,

even though it was

an impossible thing to do

about 20 years ago,

most of the fishermen go out

with a boat today

instead of dogsleds.

When Finn was growing up,

this was their winter hunting ground,

solid ice for more than half the year.

Everything happened so fast.

It's so visible.

You don't have to be a scientist

to determine what's happening.

With each passing season,

Finn watches as traditions

locked in the ice melt away.

Something

interesting in this ice,

because you

can see small bubbles.

And these bubbles are older

than all living creatures in the world.

And you can listen to it.

[Popping]

Because the bubbles

are so compressed,

and when they get out,

it's like popping.

You can talk to the ice.

That's what an intrepid team

of scientists does once a year,

fly into Greenland's interior

to listen to the ice.

Swiss camp is a scientific

research installation

built directly into the glacier

to track climate change.

Dr. Konrad Steffens

has erected 23 full-service

weather stations

that take a complete range of climate

measurements every 15 seconds,

updating global warming

computer models

all over the world.

The ice sheet is very old.

It's over 150,000 years old.

If you start to remove it,

then you actually start a process

that is unknown to civilization.

We have never seen

Greenland disappearing.

Watch it, watch it, watch it.

In 1992,

was slipping into the sea

and disappearing.

Ten years later, that number

more than doubled

to 15.5 kilometers annually.

Steffens wouldn't understand

how warmer weather affects

the speed of glaciers,

until he came upon

one of the strangest

and most dangerous features

of this forbidding landscape.

Rivers of melted ice

are cascading straight down

into the glacier,

creating huge tunnels

called moulins.

The team lowers

a fiber-optic camera.

Their hypothesis:

That melt water

has cut all the way through

to the bedrock

a quarter of a mile below,

and is lubricating

the underside of the glacier,

propelling it faster

and faster into the sea.

Fifty meters.

Sixty meters.

For Steffens and his team,

it is a chilling moment.

This shaft, and many like it,

go all the way through the glacier,

revealing a whole new mechanism

for speeding

the ice sheet's disappearance.

It's melting so rapidly now,

oceans could rise

as much as a meter

over the next century.

The consequences

could be catastrophic.

The Greenland ice sheet

actually contains enough frozen water

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