There are few truly wild places left...
...and none so majestic as this.
In winter, endless darkness is brightened...
...by the frisky dance of the northern lights.
And 30 below is the norm.
It's lovely weather for polar bear families.
One hundred and fifty thousand years ago...
...some brown bears moved north and gradually adapted.
Over time, their fur turned white...
...for camouflage.
Their snouts got tonger...
...and their noses keener...
...to detect even the slightest whiff of dinner.
This is a cold, stark world...
...but to polar bear mothers and cubs...
...it's paradise.
Because they're built for the Arctic...
...polar bears cannot thrive anywhere else.
They're at home here and only here.
Polar bears have always hunted...
...from floating platforms of sea ice.
Feasting on rich seal meat...
...has made these the largest bears in the world.
But now the Arctic is warming...
...and the sea ice is melting away...
...making it harder than ever to catch seals.
This warming...
...has left the polar bears on thin ice.
The less ice there is to reflect the sun's rays...
...the faster the ocean warms.
That's why the Arctic is warming twice as fast as any other region.
In 1980...
...the summer sea ice covered 25 percent more ocean...
...than it does now.
If the current trend continues...
...the Arctic Ocean could be free of sea ice each summer...
...by the year 2050.
Even if we can't stop this loss, we can slow it down.
Just as we release the greenhouse gases that are warming the region...
...we can help reduce them.
Ocean currents flow from the Arctic...
...and cool the entire planet.
So we're all closely connected to the top of the world.
Most Arctic glaciers are melting faster than ever before.
Ironically, the faster these glaciers melt...
...the more majestic their waterfalls.
The distance between ice packs is growing.
Nowadays, a polar bear in search of sea ice often has further to go.
It can be a swim to nowhere.
When they can't find seals to eat...
...mothers make do with meager scraps.
One mother and her cub set out on the longest swim ever tracked.
The mother swam continuously for nine days...
...covering 430 miles.
But her cub did not survive.
Some cubs do survive...
...especially if the mother is a clever scavenger.
Like polar bears...
...birds are struggling as the Arctic warms.
Arctic birds time their lives to the seasons.
So do the Inuit people...
...like Simon Qamanirq.
Polar bears surprise us in camp.
Especially in the lean summer months.
My father could read the clouds.
He knew when the storm was coming.
But now the ancient weather patterns have changed.
Our grandfathers fed their families well.
My family has always depended on snow and ice.
Nowadays when the ice melts, we can adjust...
...but the polar bears are not so lucky.
The ice is forming later in the year...
...so it's thinner.
Sometimes we fall through.
My friend Adam Ravetch has been coming up here for 20 years...
...to photograph the animals.
I love it when a mom dances with her 2-year-old cub...
...cheek to cheek.
Polar bears are great swimmers...
...even though they only use...
...their gigantic front paws.
These dedicated mothers put over two years...
...into raising their young.
Walrus moms spend even longer.
Walrus love clams.
They dive down from rafts of ice...
...which drift along and carry them to fresh supplies...
...of their favorite treat.
As sea ice melts...
...walrus are stuck on land...
...so mothers must swim farther to find food for their young.
Mothers teach their young survival skills...
...such as scaring off intruders.
One morn sent me a very clear message:
"Get lost."
Summer in the Arctic now lasts about a month longer.
Walrus and hungry bears...
...wait and wait for the sea to freeze over.
The males get restless...
...and start sparring.
They're testing each other's skills.
It's fun.
When it's not...
...mating season, these fierce rivals are content to live and let live.
The bears need...
...to get back out to their hunting grounds now that the sea ice is...
...finally freezing over.
This water is literally as cold as ice.
The salt keeps it from freezing.
These sea anemones look healthy.
But the greenhouse gases we release thousands of miles...
...away have made the Arctic Ocean more acidic.
Down here, there's only one exit...
...and it's pretty scary thinking you could be trapped.
Diving beneath the ice takes courage.
But for the people who devote their lives to studying the Arctic...
...taking risks is part of the job.
Each spring in Alaska...
...large herds of caribou set out on a long journey.
No one has ever tracked the entire migration on foot...
...until now.
Leanne Allison, a filmmaker...
...and Karsten Heuer, a biologist...
...plan to live with the herd for five months.
We're gonna do this trip to see what the caribou mothers go through...
...and to see this migration from their perspective.
And it's gonna be our honeymoon as well.
Honeymoon?
These newlyweds will follow the caribou...
...all the way to their birthing grounds.
These caribou mothers are on a tight schedule.
Yeah, that's gotta be caribou paths. Look at that drainage coming in.
Yeah, just over there...
With the warm spring, the snowpack’s melted early.
And so the rivers are flooding...
...and this is gonna be a problem for the caribou to get across.
This is climate change slowing down the herd.
This water is so cold it can stop your heart.
We've gotta get across fast.
The caribou moms are traveling hundreds of miles...
...to get to the coastal plain of Alaska...
...which is the safest place to give birth.
This year the migration is about three weeks late...
...so some of the caribou mothers have to give birth along the way.
Some of these calves are just a week...
...or two old, and they're easy pickings for bears and wolves.
We're seeing a lot of calves get separated from their mothers.
A lot of them don't survive.
The caribou finally reach their goal.
This is the place where the calves have their best chance to survive.
But just a few days after they give birth, the botflies hatch.
These bugs are potentially deadly to these caribou.
They can burrow up their noses, lay their eggs there...
...and they can set off stampedes.
It's why caribou head for the high country: to get away.
Caribou mothers are having a tough time as the Arctic warms.
But polar bear mothers face an even greater struggle.
To learn more about polar bears...
...a team of naturalists and filmmakers gathered on Svalbard island...
...in Norway.
They signed on with a seasoned captain and headed north.
My name is Bjorne Kvernmo...
...and I'm captain of this ship.
There are over 20,000 polar bears in the world...
...and most of them are camera-shy.
To photograph these reluctant film stars...
...John Downer uses clever robotic cameras...
...camouflaged in white.
The bears were curious about the remote cameras.
One bear was especially helpful.
It's hard to keep up when you're only 3 months old.
They all wanted to know what made the cameras tick.
Next year we're coming back with stronger cases.
Bears nearly always avoid people...
...which made filming them next to impossible.
Then the team got lucky.
They found a mom with two cubs, about 7 months old.
For five days, she never left their boat.
Because the sun never sets in the summer...
...bedtime is anytime.
Before long, we saw what a tough job this mother faces...
...protecting her babies from male polar bears.
Hungry males prefer seals...
...but in a pinch, they have always gone after defenseless cubs.
Even a half-ton male can be sneaky when he's on the prowl.
The mother seemed to pick up the scent of a male.
But we couldn't see him.
We didn't know why she was agitated.
We finally spotted a male quite a ways off...
...zeroing in on the mother and her cubs.
Now that seals are so hard to catch, starving males...
...might be targeting cubs more often.
Before he got close, the male lost the scent.
But next time...
...things could be much different.
The male cub followed the mother everywhere, step-for-step.
But the female was more inquisitive.
When mothers go hungry...
...they're too lean to nurse more than one cub...
...but this mother had enough milk to nurse two.
She was always on alert.
If she caught the scent of a male...
...she'd hustle the cubs off to safety.
This mother fended off four attacks in five days.
The moms have one thing going for them:
They're willing to die to protect their cubs.
Playful cubs can really work up an appetite.
Tasty seals may hide, but hungry moms can sniff them out.
When you want to grab a bite to eat up here...
...timing is everything.
Peek-a-boo.
The cubs finish everything on their plate...
...but the scent of fresh seal meat attracts attention.
Trouble always seems to...
...come along when you least expect it.
The mother leads her cubs away, downwind.
But the male picks up the family's scent again.
We watch helplessly as the male sneaks up.
The mother senses danger, but from where?
The male outweighs the mother two-to-one...
...but all that weight doesn't slow him down one bit.
Once the huge male locks in on his target, he never lets up.
The male keeps gaining on the family.
Then the mother turns to face him...
...slowing him down just long enough for her frightened cubs to escape.
At the moment of truth, the mother sent a very clear message:
"You can get to my cubs if you want...
...but you'll have to kill me first."
This brave mother was willing to do anything to protect her cubs.
But she's powerless to save the habitat they need to survive.
There are few truly wild places left...
...and none so majestic as this.
But the Arctic is warming faster than it has for thousands of years...
...and losing its dazzling crown of ice.
Arctic animals need ice to survive.
They live in a delicate balance with the natural world...
...mothers most of all.
How could they live in a world without ice?
The mothers here nurture their young so lovingly.
Perhaps they can inspire us...
...to protect their home with that same care.
Perhaps we can help keep the Arctic white.
The Arctic is one of the hardest places on Earth to survive...
...but to a polar bear, it's paradise.
Cubs play and resilient mothers thrive.
It's the only home they'll ever have.