As anyone with any awareness of Canadian events knows, the City of Fort McMurray has undergone a complete evacuation because of an out-of-control wildfire. The news has kept me with one eye locked on my media feed as I have marveled at the resilience and dignity of the people of Alberta in this hour of need. As many have suggested, this is not a time to worry about the politics, but rather one to worry about and pray for the people displaced by this natural disaster. From a political perspective our leaders have shown admirable gravitas with Prime Minster Trudeau treading the cautious line dealing directly with the wildfire without using it for political advantage. At one point in the day, it looked like Green Party Leader Elizabeth May might have decided to attempt to make political hay from the fire, but she quickly issued a correction and has since shown the calm and restraint we expect from our leaders in times like these.
Unfortunately, while Canadian political leaders have performed well, many climate activists out there have tried to use this natural disaster to score points. As I noted above, Ms. May’s first press conference sought to link the fire to climate change although she later prepared a press release saying:
“No credible climate scientist would make this claim, and neither do I make this claim. Rather, we must turn our minds in the coming days to the impact of increased extreme climate events, and what we can do collectively to respond to these events.”
The claim in question being that the fire was directly related to climate change. That being said some far less socially aware people have decided that a human disaster is exactly the right time to push their political agendas. The most obvious case being a post at Slate written by Mr. Eric Holthaus titles: Wildfire Rips Through Canadian City, Forcing 80,000 to Flee. This Is Climate Change which I have seen re-tweeted more times than I can count.
Before I go any deeper into this discussion, I’d like to clear up a few points. As anyone familiar with Alberta geography knows, the City of Fort McMurray is located in the southern edge of the Canadian boreal forest. As any forester will tell you the boreal forests are hard-wired for fire. As Natural Resources Canada puts it forest fire:
is as crucial to forest renewal as the sun and rain. Forest fires release valuable nutrients stored in the litter on the forest floor. They open the forest canopy to sunlight, which stimulates new growth. They allow some tree species, like lodgepole and jack pine, to reproduce, opening their cones and freeing their seeds.
Forest fires are simply a way of life in the boreal forests and interface fires (fires that jump from wild lands into neighbouring communities) are a particular concern for any town that has been carved out of the boreal forest.
As for climate change, the science on that topic appears to be equally clear. The climate change models tend to agree that climate change will likely result in increasing severity and intensity of future forest fire regimes. The problem lies when activists, not satisfied with what the models project; decide instead to over-egg the sauce in order to score petty political points. As an example, let’s consider Mr. Holthaus’ article in Slate.
The first section of the article is nondescript as it repeats what has been reported in any number of articles elsewhere. Climate change is not mentioned until almost half-way though the article. This seems odd to me since the title of the report specifically insists that “This is Climate Change”. One would expect a lot of meat justifying this rather definitive statement. In actuality rather than meat all Mr. Holthaus provides is some very weak tea. The only paragraph that has anything to do with climate change appears right in the middle where he writes:
One thing that is certain is that this fire has a clear link to climate change. Canada’s northern forests have been burning more frequently over recent decades as temperatures there are rising at twice the rate of the global average. A 2013 analysis showed that the boreal forests of Alaska and northern Canada are now burning at a rate unseen in at least the past 10,000 years. The extreme weather of recent months is also closely linked with the ongoing record-setting El Niño conditions in the Pacific Ocean, which tends to bring a warmer and drier winter to this part of Canada. Last month, Canadian officials mentioned the possibility of “large fires” after over-winter snowpack was 60 to 85 percent below normal and drought conditions worsened.
Now the first sentence is unreferenced and frankly unsupported. The second sentence presents a statement that confusingly, is directly contradicted by the reference provided in the text presumably to support it. The citation leads to a Natural Resources Canada (NRC) page that says the following:
This complex combination of influences makes it difficult to identify clearly whether any measurable changes in the patterns of wildland fire over the last few decades can be linked directly to climate change. Nevertheless, pattern changes do appear to be underway.
In Canada’s northwestern boreal regions, for example, the annual amount of forest area burned by wildland fires rose steadily over the second half of the 20th century. Some of this increase has been attributed to climate change.
By contrast, in Canada’s southern boreal forest, the annual amount of area burned seems to have decreased during the 20th century. This trend might be the result of climate change causing greater amounts of precipitation over time in these regions.
However, analyses of fire history suggest that it is the effect of climate variability on precipitation regimes that is the primary reason for the decreasing fire activity in southern regions.
The NRC statement clearly says that it is difficult to identify whether climate change is to blame. Yet Mr. Holthaus states the opposite that “there is a clear link”. I’m not sure how Mr. Holthaus squares that circle. Moreover, the NRC clearly points out that in the southern boreal forest (i.e. where Fort McMurray is situated) the annual amount of area burned seems to have decreased and then attributes that decrease to climate change? But Mr. Holthaus uses that same citation to support a completely different (and contradictory) claim.
At this point I can only guess that maybe Mr. Holthaus is unfamiliar with Canadian geography. My suspicion is further reinforced by reading his next sentence about the 2013 study. Now being a scientist I am prone to linking to the actual study in question rather than a ThinkProgress.org (Climate Progress) report on the study. Looking that the actual study (and not the slanted reporting of it), I discover that it deals exclusively with the upper northwestern portion of the sub-arctic boreal forest (in Alaska). This would represent the “Northwestern Boreal region” in the NRC quote above. It has absolutely nothing to do with the boreal forest around Fort McMurray, it is irrelevant to the discussion at hand. You see people forget that the boreal forests are huge covering up to 55% of Canada’s land mass and that this land area cannot be treated as if it was one single unit.Put another way, central Alberta and central Alaska are a long ways apart and experience very different climatic conditions.
The final few paragraphs of this section of the article further link the forest fire to the recent El Nino. This is a fair comment as one clearly understood downside of El Nino is reduced precipitation and an early fire season for Northern Alberta and the BC Peace District.
Looking at the supporting information provided with his article, it is clear that Mr. Holthaus failed to link the fire to climate change. Rather, the references he provides in his piece actually make it clear that climate change is not a likely major contributor to this fire. Rather the fire is a natural occurrence that may have been hastened by the effects of the recent El Nino. It is hard how anyone could realistically read those references and conclude: “This is Climate Change”.
Now I suppose I could end this piece here, but as I indicated above, I firmly believe that climate change will eventually result in increased incidence and size of wildfires in the west and so I was wondering if any signal was yet evident of that trend. Being a scientist, I decided to get the data and see what it had to say. Specifically, I downloaded the NRC National Forest Database, Forest Fires Tables- Statistics by Province. Because the files are not spreadsheet ready I had to fix them up and then I ran them through a statistical software package for environmental applications (called Pro-UCL) that I happen to have on my computer. Specifically, I looked at the data for area burned (in hectares or ha) in the Province of Alberta from 1990 through 2015. What I found was a dataset with a lot of variation.
The mean area burned for the 26 year period was 170,961 ha while the standard deviation was 229,086 ha. Any statistician looking at those numbers would recognize that we have a messy set of data with a huge difference between the lowest value (1961 ha in 1996) and the highest value (806,055 ha in 2011). Looking at that information, the 2015 value (491,768 ha) isn’t even particularly high for this dataset. To see if any trends existed in the data I ran some Mann-Kendall tests on the data. A Mann-Kendall is a test used to try and identify trends in data where you have no basis for believing the data fits a known distribution. The results of the Mann-Kendall analysis was that the number of hectares burned does not show any evidence of a significant increasing or decreasing trend over the time period covered (1990-2015). When I shortened the time period covered to start at year 2000 the p-value actually got worse (approximate p-value of 0.482). That p-value represent is pretty definitive indication that no trend exists in the recent data.
So what is the take-way from this blog post? Well the climate models indicate that in the long-term (by the 2091-2100 fire regimes) climate change, if it continues unabated, should result in increased number and severity of fires in the boreal forest. However, what the data says is that right now this signal is not yet evident. While some increases may be occurring in the sub-arctic boreal forests of northern Alaska, similar effects are not yet evident in the southern boreal forests around Fort McMurray. As for Mr. Holthaus, I would recommend that he edit his article to better reflect the citations he provides since he certainly does not do them justice in his article’s current iteration.
My final word is for the activists who are seeking to take advantage of Albertans’ misfortunes to advance their political agendas. Not only have you shown yourselves to be callous and insensitive at a time where you could have been civilized and sensitive but you cannot even comfort yourself by hiding under the cloak of truth since, as I have shown above, the data does not support your case.