Now we all agree that forest fires did not start happening just because humanity decided, fairly recently, to burn up all of the world's coal, oil and gas as fast as they could.
But the human decision to go on burning all that fossil carbon even after being warned that it would lead to global warming and stronger winds did lead directly to the fact that today's forest fire seasons around the world start much earlier and end much later.
And that they all burn much more intensely, thanks to drier hotter fuel and stronger winds bringing in more fresh oxygen.
Canada's Tar Sands are not the biggest single source of human added carbon in the atmosphere.
But they are one of the biggest and by far the biggest one that was brought on stream, after humans were told it was foolishly dangerous to increase further the huge amount of carbon we were already adding to the air in the mid 1980s.
By the time that a link between burning fossil fuels and an destructive increase in global temperatures was made obvious in the the mid 1980s, literally trillions of dollars had already been sunk into oil operations into huge efforts in Saudi Arabia and in East Texas.
For most humans, all that time, money and effort spent made it hard to stop pumping and just throw it all away. But the oil sand projects developers do not have that excuse --- they knew what their planned new operations would do to world temperatures and they went straight ahead anyway.
Moral and ethical teachers would say that as a result of going ahead despite having full knowledge of the dire consequences makes them - not Texans or Saudis - are far more morally responsible, regardless of the relatively small size, globally, of their operations.
So yes, residents of Fort McMurray, capital of Canada's Tar Sands regions, did not start today's forest fires.
But are they partially responsible for the fact that today's forest fires are, on average, worse than before ?
Yes, I believe they need share some of the blame for that.
Today we all should worry about and pray for the 100,000 people stuck in and around Fort McMurray with a huge hot fire and strong winds threatening not only the city itself but also cutting off the only escape road out of the city and through the bush.
But afterwards, we can only hope for an honest assessment of the connection between the massive amounts of Alberta oil sand being turned into atmospheric CO2 and the hotter longer forest fires in the area immediately around those same oil sand sites ....