A monster forest fire that began in early May is still burning in Canada’s vast, isolated north woods. That may seem of little consequence to anyone other than the 88,000 residents of Fort McMurray forced to flee as the blaze swept into the northern Alberta city.

Yet large fires like these matter immensely to the rest of the planet.

Fires so intense that they consume millions of acres of trees and scorch the soil on the forest floor have become the kind of extreme disruptors that are remaking the boreal forest and transforming its role as one of the world’s great protectors against global warming.

The boreal, which takes its name from Boreas, the Greek god of the North Wind,