The Fort McMurray wildfire was most likely man-made, says Chad Morrison, senior manager of Alberta wildfire investigations.

The exact reason it ignited is still under investigation, with the final report due in one month, Morrison says. No doubt the larger debate about origins of the fire will rage much longer.

As soon as the wildfire burned through Fort McMurray, a heated debate flared about what caused it.

Was the fire man-made or caused by Mother Nature? Was it simply the boreal forest doing what it does every 50 to 200 years, burning down as part of its natural regeneration cycle? Or was it caused by man-made climate change? Or perhaps it was more related to a natural El Nino weather event.

The answers are clearer now. It’s evident that numerous factors combined to create the wildfire that would grow into the Beast, destroying more than 1,600 structures and 580,000 hectares to date.

When it was first detected in the late afternoon of May 1, Alberta wildfire managers designated it as Fire 9, a two-hectare blaze about 20 to 30 km in the boreal forest southwest of Fort McMurray.

Veteran helicopter pilot Paul Spring, who has been fighting fires in the Fort McMurray area since 1980 and lost his home to the Beast, says the fire was definitely human-caused, as the skies were clear that weekend with no lightning in the area. “It’s human-related. This is not a natural-caused fire.”

The exact cause could be anything, a cigarette butt, a spark from an ATV exhaust, or even the carcass of a burning raven that got caught up in a power line, Spring says.

An Albert forestry helicopter crew out on surveillance on the extremely hot and dry day spotted the fire and landed at once, Morrison says. A team of four firefighters went to work with axes, pumps, hoses and a portable water bag.

The government’s plan with wildfires near communities is to contain them fast and have them out by 10 a.m. the following day.

“The philosophy is: ‘Get ’em quick, get ’em small,’ ” Spring says.

The fire’s location was called in and within two hours four water bombers were pounding it, Morrison says. It grew to 60 hectares in two hours. By midnight, it was 900 hectares and moving rapidly because of the parched, hot conditions.

“It doesn’t matter how many tankers or dozers you would have put on this thing, it wouldn’t have been able to stop it,” Morrison says. “Mother Nature is sometimes going to do what it’s going to do.”

On May 2, favourable winds kept the fire out of Fort McMurray, but on the morning of May 3 strong winds from the west blew the fire in, taking out numerous homes in the Abasand, Waterways and Beacon Heights.

The fire then jumped as far as 1.2 km across the vast Athabasca River valley to the north and burned into Fort McMurray’s 40,000 people suburb. This massive suburb is surrounded by forest and also has the large Birchwood ravine running through it.

If that ravine ignited, the whole community would have gone up in flames, but that’s where the Alberta forestry and city firefighters were able to make their stand. They battled the fire three straight days and nights, preventing the fire from destroying the vast majority of homes.

“There’s no question in my mind that that saved the rest of the city,” says regional fire Chief Darby Allen.

As for the cause of the fire, it’s clear that Alberta’s aggressive forest fire prevention around communities like Fort McMurray has led to an older forest with more deadfall fuel set to burn hot and fast when it ignites.

It’s also evident that man-made climate change had an impact. The winter was again warmer and there was an early snow melt, making for a much drier forest this spring.

Climate scientist Paul Roundy has said an unusually hot El Nino is the main culprit, as it is the specific cause of this year’s hot and dry April weather pattern in Alberta.

Social activist Naomi Klein also recently blamed El Nino, but said it has been affected by climate change. “It is El Nino supercharged with climate change,” said Klein. “That’s why temperature records are being broken all around the world.”

Roundy says some climate models suggest that a strong El Nino could become twice as frequent due to climate change, but it’s difficult to confirm this theory now. “The observed frequency of strong El Nino does not appear to be trending higher.”