BC Wildfires – Human-Caused Climate Change or Pine Beetles and a Dry Year

Contributed by Ralph Bullis, P. Geol., FGC © Sept. 2017

With such a bad wildfire season in BC and with so much disruption in the province, I suppose it’s inevitable that someone (Al Gore? CBC? The Weather Channel?) would step up and state categorically that this is all caused by humans using fossil fuels.

However, if you look up the BC government and federal government statistics on BC wildfires and plot out the past 40 years – since 1977 – and what you find is somewhat surprising. First of all, there has been a steady decrease in the number of fires over that period with the average being just over 2,100 per year. This year, up to early September we’ve had about 1,230. Yet, the number of hectares burnt is huge – almost 12,000 square km – more than the previous worst in 1958 (with about 8,550 sq. km.).ralph bullis part one graphs bc wildfires

The second thing that surprised me in the data is that up until about 2002, the average number of sq. km. burnt per year was about 320 and the trend was flat (with an anomalous spike in 1982 with about 2,800 sq. km. burnt). But since 2002 we have seen a significant increase in the areas burnt – in fact the average from 2003 to 2016 is about 1,550 sq. km. or about 5 times the average up to 2002.

So what’s going on? How can the number of fires annually be steadily going down yet the amount forest being burnt increasing and the increase in burnt areas beginning about 2002?

Well, I talked this over with some friends and the suggestion arose that perhaps the insect infestations might play a role.

So, I retrieved the insect infestation data and when I plotted the pine beetle infestation numbers, it turns out that there was a rapid increase in the number of hectares infested starting in about 2000. As you can see from the attached plot, the number of hectares under pine beetle infestation climbs rapidly from less than 200,000 ha in 1999 to over 10 million ha in 2007. The good news in all of this is that the beetle infestation since then has been rapidly dying off, down to just over 300,000 ha in 2015.

ralph bullis part 2 pine beetles

So, just at the same time period when extensive areas of forest were dead or dying due to pine beetles we see an anomalous uptick in forest fire extents.

ralph bullis 3 cost of wildfires

Now, the coincidence of larger fires and extensive forest kills due to pine beetles may be just that – coincidence – and there may not be a correlation. But, if it comes to a choice of blaming the extensive forest burns on climate change or on those huge expanses of highly combustible dead forest due to pine beetle infestations, I know what the scientist in me would select.


Ralph Bullis is a UBC Geology grad (1970) who has worked for over 40 years in the mining and exploration industry, in many countries on various projects. He has special expertise in Securities filings for regulators and for oversight of exploration and company due diligence activities. A registered Professional Geologist since 1982, he currently sits on the Discipline Committee of NAPEG. In 2013, Ralph Bullis was made a Fellow of Geoscientists Canada (FGC) for contributions to the industry. He has prepared and presented several conference papers on gold, gold mines, statistics of ore reserves and I have had several papers published.
Ralph says: “I have followed the climate debates with interest ever since the mid-70s when “global cooling” was all the rage. With my background in statistics, evaluations and due diligence I would have to say that if the IPCC were a junior mining company it would have been de-listed years ago.”

1 Comment

  1. Carolyn Carruthers

    Thanks Ralph for the information.
    Do you have any more about how the fire started? Was it human caused or caused by lightening?

    Also wondering if you have done research on the California wildfires.
    Thanks for the scientific research!

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