The planet’s warming had a strong influence on destructive wildfires in Canada that have raged across Ontario and the Northwest Territories since late June, making the extreme fire weather that fueled them at least twice as likely, according to a report published Thursday by World Weather Attribution. With global temperatures roughly 1.4C above pre-industrial levels, Canada is experiencing a notable rise in extremely hot and dry weather — the ingredient required to turn minor ignitions into infernos. Researchers found that the severe conditions behind the recent blazes in Ontario are now twice as probable as they would be in a world untouched by human-caused greenhouse gas emissions. The change is even more stark in the Northwest Territories: There, a week of fire weather as extreme as this year’s — which would occur once-a-decade without global warming — is now estimated to return every two years.