(polar bear whining) - It's been four months since your last bite.
(snow crunching) You may fool yourself into
digging out some frozen kelp but you know that dinner
actually sits comfortably (seal purring)
200 miles away. It's so frustrating.
(polar bear groaning) The last thing you need right now is a huge male looking for trouble. (polar bear roaring) (deafening winds) At first glance,
(dramatic orchestra music) the Arctic feels brutally devoid of life, though a select group of animals have figured out a way to thrive. (seal moaning) (polar bears moaning)
But the real force here works quietly underfoot. Every winter, sea ice
starts small and delicate. (ice crackling)
Then it grows over millions of square miles. How is it possible that this freezer holds the key to our entire planet? (ice cracking)
Like a lung, sea ice breathes life into the Arctic every year. In a cycle that impacts the
climate across the globe. This is the story from the
edge of the Canadian Arctic where it all starts. My name is Bertie Gregory and I'm a National Geographic
wildlife filmmaker. Everything is at stake. They're all waiting for the Big Freeze. (temperature clock ticking) (waves crashing)
(mellow orchestra music) Temperatures are starting to drop in the Hudson Bay, but it needs to get a lot colder for the salt water to
completely freeze over. Until then, the seals
are just too far away and the hungry bears have
no choice but to wait. (deafening wind)
This guy is a big bruiser and he's coming in, like
all the other polar bears, they're coming to the water's edge, ready for the Big Freeze. But right now, the ice isn't quite ready. You can see him (chuckles)
kind of falling through it and stumbling on his way. (snow crunching) You know, you spend four
or five months on that, starving, not eating anything. You know that as soon as that sea freezes, that's your fast food buffet is ready. (sad orchestra music) (winds roaring) The Arctic hosts our planet's
most brutal snowstorms. (snow crunching)
But today, weather is the last thing this bear
needs to worry about. (dramatic music) He's moving on. This big male on the left approaching the even bigger male on the right, so we about to get some action. (snow crunching)
(polar bear growling) (thrilling orchestra music) (polar bears roaring)
(climatic orchestra music) Oh, they're just battering each other. (polar bears grunting) In case, we've added an unnecessary amount of dramatic music. You be forgiven for
thinking that these two guys are in some brutal fight to the death, but actually this time of year, males don't really have
anything to fight over. Here, there's no females in heat. There's no food. And instead, they've got
a bit of a bromance going. (polar bear whining)
And now, I mean, look at them after hammering each other, having a little snooze together. Although they're solitary
most of the year, when males finally meet up, they can be really playful. They often pair up with a sparring buddy because in a few months, they'll be on the ice fighting in deadly battles over breeding rights. (polar bear groaning) (playful orchestra music)
But polar bears are incredibly well adapted to the challenges of these hardships. Their enormous 12-inch white
paws are like snowshoes, spreading their weight on thin ice. Their short, gripping
claws and soft footpads also prevent them from slipping. The bear's narrow head and long neck allows them to grab seals through their breathing holes in the ice. And if you have to pull a
600-pound seal out of the water, then a massive set of canines with setback premolars, allow you to bit down deep. But hands down, their key adaptation is their incredible thermal insulation. (winds roaring)
If we switch from a normal camera like this camera and the camera you're
looking at me on now, to a thermal camera, you're now looking at me in heat. So, if I take my glove off, you see how my hands and
my face are bright orange. That means, I'm losing
heat to the environment like there is no tomorrow. I'm so badly adapted to this place. Whereas, if you look at the bear, he's that dark purple, almost black color. And that is because of
that thick, thick fur, which obviously I don't have. My biggest challenge here
is keeping warm enough, whereas his is keeping cool enough. (wind howling) (pensive orchestra music)
Hang on, Steve. You see that bear over there? He's coming in pretty good. - Hey, buddy. You need to start thinking
twice about walking in. (snow crunching) - There are very few animals that will actually try and hunt people. And polar bears are one of those animals. - Hey, slow down. Slow down. Hey, we're not an easy meal. Hey, hey.
(rocks banging) Slow down, hey!
(snow thrashing) Slow down. I'm gonna hit you with the rock. Hey! Close enough. No, no, no. No. (polar bear huffing) Hey, sit down. (polar bear whining)
Sit. There you go. - Well, Steve told it to sit and it sat. (wheezes) Unbelievable. - [Steven] Hey, go play with your friend. - This bear will just have to wait for the Big Freeze to get his dinner, along with the others, all stalling for time along the coast. (polar bears whining) (thoughtful music) The most powerful force in the Arctic starts small, really small. (ice crackling) So fragile, that it could
break in your fingertips. It grows inch by inch, almost when no one's looking. But once it starts, there's no stopping.
(dramatic orchestra music) The water hits 28.8 Fahrenheit and the Big Freeze has finally arrived. (stern violin music) And finally what was
thousands of miles of liquid has turned into this
rock-solid ice pathway across the ocean. (strict violin music) Polar bears have depended on
The Big Freeze for millennia. The problem is that our warming climate is delaying its arrival by
more than a day each year. That means, that this generation has lost at least a month of hunting that previous ones relied on. (seal purring) We've got to turn this around and save our planet's
most vital cooling system. (snow crunching)
(polar bear grunting) And off he goes Slowly but surely, our
bear starts his trek out over the ocean, for as long as the ice will let him. (snow crunching)
(dramatic orchestra music) (sad piano music)
