But scientists are warning that climate change could spell danger.

As the temperature rises and melts, ice, polar bears need to hunt seals.

They're being forced to spend more time on land, bringing them closer to people.

Our science correspondent, Victoria Gill, has been in Churchill along with a team of polar bear researchers.

There's a polar bear under our tundra boogie, right now.

He's very curious about us.

Oh my word.

At the height of polar bear season in Churchill, Manitoba, conservation scientists are out on the tundra, monitoring one of the most southerly polar bear populations in the world.

So the polar bears are starting to gather in this area because there's going to be sea ice here first.

And for polar bears, sea ice means food.

The bears are waiting for the bay to freeze so they can use it as a platform to hunt seals.

But as the climate warms up here, the bears are having to wait for longer.

We had about 1,200 polar bears here in the 1980s and now we have closer to about 618.

So we've lost almost about 50% of these polar bears in the last several decades.

And we've tied that to these bears are on land about a month longer than their grandparents were.

In the long term, this threatens the survival of this polar bear population.

But in the short term, it means the bears here are getting hungrier.

The longer they're on shore, the longer they're fasting.

And the longer they might need to start looking for alternative sources of energy and food.

And sometimes those sources are us.

That poses a particular challenge for Churchill and the team of rangers who run its Polar Bear Alerts programme.

I came down this trail and I caught him up on this deck.

It was testing the door.

What did you do?

So at that point you haze them, right?

You use your vehicle, horns, croc or shells and you chase them in a desirable direction, which in this case would be away from town.

This is a place that takes pride in setting an example for how humans can coexist with these big predators.

Everyone here that we've spoken to is very aware of it all the time.

And should we go?

I can hear cracker shots over there.

That means that they may be moving a bear.

There's a bear there.

It's crossing the road.

Get in the car.

We heard crackers going off and now the Polar Bear Alert team are moving around.

So we're going to get back in the car.

So you can just see it through the trees there.

We could see the Polar Bear Alert team's quad bikes and their trucks moving the bear along.

While a loss of sea ice threatens the survival of Churchill's polar bears, it could also open up the bay and the town's port for more of the year.

The new marine observatory here, that opened just this year, is carrying out experiments that aim to better understand what winter conditions on the bay will be like in the future.

The bay is open water, essentially, on average, about five months a year.

And it's on its trajectory to become all year round.

And my colleague right there, he's working specifically on improving the projection of ice conditions to facilitate, to help make better decisions on the shipping season.

This is a town preparing for a future without sea ice in the bay.

The town's mayor, Mike Spence, says that could present opportunities.

What do you think this place could look like in ten years' time?

It'll be a bustling port.

The future looks bright.

The fate of the polar bears, of the polar bear capital of the world, though, depends on us, and whether we can rein in rising temperatures and preserve the ice that they depend on.

We can keep Arctic sea ice in the north and protect the species as a whole.

Sea ice is so much more than just, like, frozen ocean.

It really is, it's a garden, it's a platform, it's access to food.

It's life, really.

Victoria Gill, BBC News in Churchill, Manitoba.