A new report says the conditions that fuelled July wildfires in Ontario and the Northwest Territories were made roughly twice as likely due to human-induced climate change.

The report by an international team of scientists says what were once rare fire conditions are now increasingly likely today due to climate change, driven by the burning of fossil fuels.

The World Weather Attribution report says early observations indicate the hot, dry and windy conditions underlying fires in the Northwest Territories could now be expected to occur every two to six years, and every six to 15 years in Ontario.

In a world without human-caused climate change, the report suggests those conditions would have been much rarer, or less than once in 40 years.