Subarctic boreal forest, vital for the planet, is at risk

It burns, it drifts, it falls victim to insects. And it's shrinking.

The boreal forest, which is second only to the Amazon in terms of its vital role in ensuring the future of the planet, encircles the Arctic-and it is in just as much danger from climate change as the South American rainforest.

The deep, verdant green ringwhich stretches across Canada, Scandinavia, Russia and Alaska-has been weakened by increasing forest fires, the melting of permafrost, intensifying insect infestations and warming temperatures.

Experts are categorical in their warnings: the forest is encroaching on the tundra, and the prairies are slowly taking the place of the trees.

In his cabin in Quebec, not far from the banks of the St Lawrence River amid the trembling aspen and black spruces, Jean-Luc Kanape, a member of the Innu Indigenous group, says he likes to feel the "energy of the wind, the cold."

"When I'm in the heart of the forest, I feel like I'm part of it. The trees are like my roots," says the brawny 47-year-old, his hair askew and his skin bronzed from the sun.

Kanape has dedicated his life to the protection of the caribou, a species whose habitat is under threat because of the effects of deforestation and global warming. And he is worried. "We often say we need to save the planet, but that's not true," he says, suggesting humanity's own existence is what is at stake.

The forest-named for Boreas, the Greek god of the north wind-covers 10 percent of the world's land surface and has a decisive impact on the globe's northern oceans and overall climate.

Its 1.2 billion hectares (nearly three billion acres), which account for nearly a third of all forested land in the world, help slow global warming by absorbing a significant amount of carbon emissions.

The boreal forest holds twice as much carbon as all tropical forests combined, and also helps purify a massive amount of freshwater.

There have always been natural changes to its makeup, but scientists are now concerned that those changes are happening more often, and are even becoming the norm.

Dead tree trunks stretch towards the sky-ghostly white shadows staining the green canopy in this corner of Alberta province.

On the ground, shrubs and grass battle to stay alive.

"I'll never again see a spruce tree in these hills," laments Harvey Sykes, a 70-year-old former oil industry worker who lives in the Fort McMurray area, home to the world's biggest oil sands production complex.

Here, the boreal forest still bears the signs of a huge fire in May 2016 that sent 90,000 residents scrambling for safety from a wall of flames along a lone access road.

"This one was a monster," recalls Sykes, pointing to the hills where the blaze began. "A fire like that, you don't confront it... you get out of there."

Like many in the region, Sykes lost everything in the inferno-his house, his belongings and a lifetime of mementos.

The wildfire remains the most destructive natural disaster in Canada's history, with 2,500 buildings destroyed and damages totalling nearly 10 billion Canadian dollars ($7.4 billion US).

It was the first time in the country's history that residents found themselves in danger as a direct result of the consequences of climate change on the boreal forest.

Today, wildfires are multiplying in Alaska, Canada and Siberia. They are one of the greatest threats to northern woodlands even if, paradoxically, they are also essential to the forest's survival and evolution.

Fires release precious nutrients into the forest soil, and create holes in the tree canopy that allow sunlight to break through, contributing to the growth of new trees.

In the boreal forest, the most prevalent type of fire is a crown fire, which spreads quickly from treetop to treetop. These blazes are more intense and more difficult to fight than fires on the ground.