Hello! It’s definitely not midweek anymore but that’s okay.
In light of the fires in Fort McMurray (poorly timed illumination pun not intended), I’d like to take some time to look at wildfires in general, including why we get absolute beasts like the one that’s been absolutely destroying northern Alberta over the past couple of weeks.
Superficially, forest fires are pretty much the same as any bonfire, and have mostly the same ingredients. Unfortunately, in the same way that nuclear reactors and atomic weapons are made from the same things, something about scale and presentation can turn a fun backyard activity into a city-wide evacuation. Forest fires vary widely in intensity and size as a plethora of factors come together to help or hinder the growth and success of the blaze. Such things as the moisture and composition of the fuels, the windspeed, and simply how much wood there is to burn can drastically affect the severity of a wildfire.
Wildfires have probably existed for as long as forests have on earth, with the first record appearing about 420 million years ago. This is around the same time that major forests began to develop as plants exploded into the continents using their sick, newly evolved vascular tissue. Interestingly enough, this led to a rapid increase in the amount of oxygen in the atmosphere, which in turn (possibly) lead to a massive increase in the number of fires that occurred. No one quite knows the extent to which this developed, as if the air had actually reached 35% oxygen all forests should have been annihilated in a series of catastrophic fires that probably didn’t happen (geology is HARD). 200 million years pass as fire levels fluctuate up and down, until (relatively) recent history, as about 10 million years ago there was a sharp increase in fires all over the world after what looks like a 45 million year hiatus of low activity. It’s incredibly difficult to say why this happened, as there was no new plants, oxygen levels slowly decreased and the global climate really didn’t change.
(author’s note: if this article teaches us anything, it’s that geologists, like biologists, have insanely hard jobs and probably deserve more respect)
The trend continues until incredibly recent history and well into human domination of the entire planet. Because of the relatively rapid fire cycle, the natural state of forested regions turned into one of balance as the small burns allowed fire-resistant species to dominate while the more vulnerable ones were kept in check, creating a nice feedback as fewer highly flammable plants meant the fires stayed small. Unfortunately, the sprawling size of areas like the North American boreal forests means that even small wildfires are annoying to expanding populations, and the general view was that they were too dangerous to have around. As a result, the beginning of the 20th century marked an increased effort in Canada and the U.S. to suppress all wildfires by any means necessary. This was a highly successful move, and the first ~60 years of the last century saw a decrease in fire activity and the area burned each year.
However, as with making bread and upgrading computers, the human race has proved to maybe be a little too good at stopping fires from happening, and the downward trend slowly stalled and turned around in the early 80s as:
1. ecologists and forestry councils realized that wildfires were a natural and critical part of renewing these ecosystems, and as such
2. decades of stopping this renewal process had generated huge forests that were absolutely loaded with fuel, as old growths and fire-vulnerable species became abundant.
For reference, in 1910 1700 small-moderate fires burned 3.1 million acres total in the northern Rockies, while in 2002 two fires in Arizona and one in Colorado were responsible for burning 588 000 acres alone. To be perfectly fair, 2002 was overall a pretty terrible year for wildfires all over North America but it does put into perspective just how much a few massive fires are now responsible for most of the burning each year. More specifically, Natural Resources Canada reports that the ~3% of fires that exceed 200 hectares (~500 acres) in size represent 97% of the burn area each year.
Speaking of overall bad times, we come to 2016, and Alberta. As an absolutely monstrous El Nino oscillation has dominated the Pacific this year, and Edmonton has received 37 of the normal ~120 mm of precipitation this year (about 30%) and northern Alberta experiences similar conditions, it’s little wonder that we’ve had such a wild start to forest fire season. The ground was also absurdly hot for this time of year, as shown by this lovely map of the mean land surface temperature anomaly of the week the fires started (April 30 to May 7):
The scale of colours ranges from deep blue at 12°C below the 2001-2010 average for that week to deep red at 12° above. Notice how almost the entirety of central Canada is dark red.
In all fairness, big forest fires happen every year, sometimes they happen in May, and sometimes they threaten or destroy towns or cities. Considering that Fort Mac was built right up against the edge of the surrounding forests (that were likely heavily suppressed, y’know, because people generally don’t like fires near their houses), it was only a matter of time before some fire at some point came knocking on the door. That said, it’s pretty terrible that the fire that had to happen also came during a year when everything is hot and dry, and during a week that experienced insanely high winds. To continue the awful personification from earlier, a fire did knock. Knocked the door down, that is Hagrid-style, although there was no gentle half giant and no birthday cake standing in the entry. Instead came disaster and a serious amount of politics caused by a terrible economy and insane weather.
It’s important to note that this was, ultimately, a natural event. Fires are an integral part of the boreal forest, and even if the start itself was human (which is likely, but not for certain), it’s good to remember that it was also only a matter of time before lightning did the same. Exacerbated as it was by decades of suppressed fires and a particularly ridiculous start to this particular year, we have to remember to stand by the people affected, no matter the cause, no matter the source of their income.
In the meantime, the Red Cross is still accepting donations, and you can do so (if you’re inclined or haven’t already) by donating here or texting REDCROSS to 30333. And respect the fire ban, kids, our firefighters are already super overworked.
Wow, so I know I learned an awful lot and probably did a terrible job explaining it, so if you want to check over what I wrote, here’s all the sites and papers I got information from, in no particular order:
BONUS: .gif of fire risk and fire risk projections over the past couple weeks collected by the Globe and Mail from the nrcan website.
So, that's all. I'll see you soon