With an extinction threat looming, no wonder polar bears are at our door and on the roof

Our planet is changing. So is our journalism. This column is part of a CBC News initiative entitled "Our Changing Planet" to show and explain the effects of climate change. Keep up with the latest news on ourClimate and Environment page.

Bobbi Stevens had no idea she was going to make national news this month when an unusual visitor a polar bear not only came to her house, but made its way to her roof.

Stevens lives in St. Anthony, a town on the northern tip of Newfoundland, not far from Labrador and the sea ice that the north Atlantic serves up around this time of year.

"My roof's not that strong and I only have one door on this house. One less nail and he might have come through," Stevens said in an interview with CBC.

"I'm just glad I didn't know he was there when he was there."

Stevens learned about the bear from the barks of her dog, and got a surprise when she opened her door. "I looked up on the bank above my steps [and] this polar bear was looking me in the face."

She didn't know that the bear had been above her head until she learned that a neighbour's security camera had recorded the animal's explorations.

WATCH | Polar bear checks out a rooftop on a home in St. Anthony, N.L.:

Polar bear climbs onto roof of Newfoundland home

2 years ago

Duration 0:52

A polar bear climbed onto the roof of Bobbi Stevens's home in St. Anthony on Sunday evening.

Polar bear sightings in communities along Newfoundland and Labrador's coastlines are not that rare at all, especially in recent years. More years than not, there is a warning somewhere in the province, sometimes in multiple places, for the public to beware of polar bears on the land, and not on ice or at sea, their more usual terrain.

Shrinking fields of ice

But shrinking ice fields in the Arctic a factor accelerated by climate change have had enormous consequences for an animal that is literally linked to the region. The word "arctic," after all, comes from the Greek word "arktos," meaning "bear."

The very name of the animal polar bear ought to remind us that it should be found (and flourishing) closer to and not farther away from the North Pole.

• Do you have a question about climate change and what is being done about it? Send an email toask@cbc.ca

Yet here we are, and there they are. In preparing this column, I looked at our coverage over the years of polar bear sightings and encounters. There have been plenty of them, and a few themes emerged, including bears showing up in places like La Scie, Fogo Island, Greenspond,Grates Cove, and even as far afield as the Hibernia platform, which is anchored about 315 kilometres southeast of St. John's.

Violent encounters between bears and people are not common, but they do happen. For instance, a hiker was seriously injured in Torngat Mountains National Park nine years ago. More often, fortunately, people have been rattledbut not hurt.

Polar bears, after all, are more apt to eat seals, not people. But to find the seals, they need ice, and that is where things have gone proverbially south.

Much less ice, much less time to hunt

Scientists have been collecting evidence for years about the loss of sea ice and piecing together the impact it has had on polar bears. The impact of course extends beyond that species, as they and we are all connected. Last year, CBC Newfoundland and Labrador produced a series called Thin Ice, which examined how dwindling ice has affected the Inuit of northern Labrador.

For generations, residents of those Inuit communities relied on the ice for transportation and hunting routes. The loss of ice is one of the factors that have pushed Inuit to depend increasingly on store-bought food.

Polar bears have been stressed with the loss of ice, with some researchers raising concerns for years now about possible extinction.

"It's clear that, you change the sea ice, you affect the bears," Andrew Derocher, a University of Alberta professor and polar bear authority, told CBC News in 2016.

"There's only so far that you can push them. At some point there's just not enough sea ice for them to persist in an area and we would expect them to blink out."

Here's how seriously things have been changing in a relatively short period of time. Data collected since the late '70shave shown a dramatic erosion in the pathways bears can hunt in the Arctic. A study published six years ago by the European Geosciences Union found that by the middle of the century, there will be seven fewer weeks a yearthat polar bears can hunt.

That means bears have been going farther afield for food, including marathon swims over a few days in the melting Beaufort Sea. We also have learned that other available foods, like berries, are not enough to complement a diet that is heavy on seal blubber.

The crisis affecting polar bears has been playing out before eyes for years, and communities that are closer to the sea ice have been getting used to perennial visitors. Consider Black Tickle, a small fishing community in southern Labrador, not far by sea from St. Anthony.

"I think we've had 17, 18 or something come through," resident Jeffrey Keefe said earlier this month. (It's happened before; in 2015, Keefe said dealing with polar bears was "like herding cows.")

It's obviously a change in ways for humans and bears alike. Keefe related that this season, polar bears have been spotted away from the shoreline.

"We've had polar bears actually in through the trails, in through the woods, because they're getting drove ashore in different areas," he said.

WATCH | Inuit leader Natan Obed talks candidly about the threats that climate change poses to Canada's North:

Climate change is causing a disconnect for northern Labrador communities, Inuit leader says

3 years ago

Duration 2:35

Natan Obed describes how daily life has changed, just in his own lifetime

Keefe points to climate change for unpredictable changes in ice.

Friday was Earth Day, a day earmarked tolook at environmental issues and climate change. It's hard locally not to connect the dots with shrinking ice caps and sea ice and a species that is struggling to adjust.

Read more from CBC Newfoundland and Labrador