Saturday, May 07, 2016

The Meaning of the Fort McMurray Fire

Ironic. Safe to say there are a lot of people there who are opposed to reducing the use of fossil fuels, because of the oil sands operations there.

I suggest reading the whole article at the following link:



by Greg Laden on May 6, 2016

It is hard to understand the connection between climate change and wild fire. This is in part because it is hard to understand the factors that determine the frequency and extent of wild fires to begin with, and partly because of the messiness of the conversation about climate change and fire. I’m going to try to make this simple, I don’t expect to succeed, but maybe we can achieve a somewhat improved understanding.

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Fires start, and humans starting fires is, really, just as “natural” in a way as any other way to start a fire. But fire starting is not context free. It is difficult to start a fire with human intent, carelessness, accident, or with lightning, in a wet forest. Stuff doesn’t burn that well, so a fire might start up but then it dies out. If, however, there is plenty of fuel and the fuel is dry, a real fire is more likely to get going. The conditions in Alberta (and over a much larger area, including the northern Tier of the US states at the moment) are ripe for fires to get started right now, and in many areas, have been so for weeks.

Once the fire starts, it burns. The more fuel, the more intense the burn, and the larger area with fuel, the larger the fire may become. Winds push the fire along and spread it. So, dry conditions with a good breeze are optimal to get a fire started and spread.

The conditions in the vicinity of Fort McMurray have been dry all winter. There was reduced snow pack, and the snow pack melted away quickly. there has been very little rain. There has been a lot of wind, which further dries things out. There has been a lot of heat, a warmer atmosphere, which exacerbates the drying. The forested areas of Alberta are ripe for fires starting, and for their spread, and for their intensity.

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Weather is climate, now, just as climate is weather over the long term. If the climate changes for any reason, the weather changes. In other words, the relationship between climate changing and weather being altered is a natural tautology. All weather events are related to climate because they are climate.

The relevant question, then, is not is there a link between A and A (because they are the same things at different scales) but rather, is the nature of a potential weather event — including it’s likelihood as a statistically defined hazard, or other variables such as how big, how wet, how hot, how dry, or when it happens, etc. — different now than it would have been in the absence of surface warming cause by the human release of greenhouse gas pollution?

When it comes to fire, the answer is, simply yes. But, the reasons for this are complex.

Surface warming has caused … wait for it … warming. The warm air exacerbating the Alberta fires is warm air we can presume is contributed to by an El NiƱo event (which has been winding down but surface temperature remain elevated after the event itself is over), riding on top of surface temperatures elevated by global warming. There are a lot of ways to get warm air into Alberta in May, but we know that the northern regions have been warming apace with global warming, with winters shorter, snow pack melting out faster, etc. So we can be reasonably confident that the “warming” part of “global warming” can account for … warming, generally, probably here, now, this Spring.

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Surface warming has caused atmospheric moisture to become more clumped. This has to do with differential warming in the Arctic vs. the rest of the planet, which has caused the polar jet stream to change its characteristics, so instead of being usually straightish as it runs around the planet, it seems now to be usually slow moving and wavy. This has caused large areas of the landscape to experience prolonged dry conditions, sometimes for months (then it rains) and sometimes for years (like in California, where there is a drought). Meanwhile, other areas experience multiple 100-year or 500-year rainfall events with flooding in a short period of time. The forested regions of Alberta have been dry.

The same effect might also have brought prolonged and energetic winds to Alberta over recent weeks, making it more dry and fanning and spreading fires once they start. I quickly add that I’m not sure if Alberta has been exceptionally windy or, of so, why, but that is something that should be examined.

Finally, climate change has helped the spread of the pine bark beetle in the region. Fort McMurray is within the area of increased pine bark beetle activity, but other areas farther to the west are even worse. These beetles turn normal trees into kindling, providing fuel for any fires that start in the area.

So, yes, the Alberta fires, and other fires in western Canada and in the northern tier of the US are more frequent and larger than they otherwise would have been because the things that cause fires to get started and spread are worse because of climate change.

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The people of Fort McMurray did not decide to cause climate change. They decided to get a job so they could eat and live in a house. Same with the coal minters in West Virginia or the workers in a Koch refinery somewhere. It is only form a position of great and unexamined privilege that one can see the victims of this enormous catastrophe as getting what they deserve. [We need to help the people who are being displaced from these jobs that are destroying us.]

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