Northwest Wildfires: Are We Seeing a "New Normal" Due to Climate Change or and "Old Normal"?

Some of the news media, politicians, and environmental advocacy groups have claimed that the smoke hitting western Washington during the past two summers are a "new normal."   That Northwest summers should be smoke and fire free, and that anthropogenic global warming has created an new regime of fires and smoke that has never been experienced before.

As I will describe below, those making such claims are seriously misinformed

Wildfires are an essential part of the ecology of our region, particularly east of the Cascade crest.  When European settler reached the region in the 1800s they found an area that was frequently smoky in summers, with major fires.  And the reason that current inhabitants of the region think smoke is an outlier is because of nearly a century of fire suppression in the West.

To put it succinctly, during the past few summers we have gotten a taste of the "old normal", one that was very familiar to our great grandparents and their predecessors.  And one that we will experience frequently in our future if we don't take steps to restore our forests and to bring back regular fire.

An excellent illustration of our firy and smoky past is found in this graphic produced by the Oregon Department of Forestry (OD) showing acres burned and number of fires from 1911 to 2017 (see below). 

The number of acres burned early in the 20th century absolutely dwarfs when are experiencing recently.   And there has been no increase in the number of fires.  During the 1940s, we got good at suppressing fires (with new technologies such as airplane drops of water/retardant) and the number of fires dropped precipitously, with a modest recent rise (but nothing compared to the 1917-1940 period).

Smoke and fire was part of life here in the Northwest before the period of near-total suppression began around approximately 1940.  Native Americans started fires to encourage the productivity of the land.  The early settlers of the region experienced one major fire (with lots of smoke) after another.  Some examples will illustrate.

In 1844, a wildfire approached and almost destroyed Fort Vancouver, north of present-day Portland.  A year later, the Great Fire of 1845 burned down the north half of Lincoln and the south half of Tillamook counties destroying most of the old growth timber of the area (1.5 million acres).  In 1853, the Yaquina fire engulfed 450,000 acres in Oregon, followed by the Silverton Fire of 1865 (million acres in Oregon) and 1868 Coos Fire (Oregon, 300,000 acres).

1895 was a particularly dry, warm year in Washington State.  A detailed report by the U.S. Weather Bureau office here in Seattle reported:

August 1895 was an excessively dry month in all parts of the state.... On many days that were otherwise clear the sun was almost entirely obscured by excessive smoke from forest fires, which extended over a great part of the eastern, as well as the entire western section of the state.

Mark Twain had been invited to speak in Olympia that summer but his reception was smoked out by extensive fires on the Olympics.  An amusing repartee followed:

Mr. Twain, as chairman of the reception committee, allow me to welcome you to the capital of the youngest and most picturesque State in the Union. I am sorry the smoke is so dense that you cannot see our mountains and our forests, which are now on fire.’ Mark said; ‘I regret to see—I mean to learn (I can’t see, of course, for the smoke) that your magnificent forests are being destroyed by fire. As for the smoke, I do not so much mind. I am accustomed to that. I am a perpetual smoker myself.’”

Didn't mind our smoke

A few years later, a huge fire--the Yacolt Burn--- burned 238,000 acres in Clark, Skamania, and Cowlitz counties resulting in over 65 deaths. The fire dropped one-half inch of ash in Portland. The smoke was so thick that street lights glowed at noon in Seattle 160 miles  away and ships on the Columbia River were forced to navigate only by compass. It makes our recent experience seem like a walk in the park.

But the real show stopper was the Big Burn of 1910, which destroyed 3 million acres and killed 87 people, a vast area encompassing parts of eastern Washington, northern Idaho, western Montana, and parts of BC.   The Big Burn was a turning point in many ways, pushing the U.S. government to get into fire suppression on a massive scale.   At first, our technology and organization was not up to the job and major fires continued, such as the Dole Valley Fire of 1929 that burned over 300,000 acres in Clark and Skamania counties.

But by 1940s, we became very good at it.   Active suppression kept down the number fires and quickly extinguished most of the ones that did start.  

Forests that once encompassed big trees with substantial spacing between them, started to fill in as the big trees were removed and the absence of fires allowed dense, unhealthy stands of smaller trees to develop.  We created sick forests where beetles and other insects did great damage, untempered by frequent fires.  Degraded forests, where huge amounts of "fuel", enhanced by slash left on the ground by careless logging, became primed for huge, catastrophic fires. And we decided to expand our homes and recreation in to the forests, endangering the new residents and initiating many fires.

Today, the bill for our suppression of fire and poor forest management in the Pacific Northwest and British Columbia has now come due.  Those who blame our dangerous situation on a "new normal" solely resulting from climate change, are not only misinformed, but they can act as obstacles to the actions that are acutely needed:  a massive effort to thin our forests and bring back low-intensity fire.  Some enlightened politicians, like Senator Maria Cantwell, are calling for such an approach...they should be supported.

Warming from increasing greenhouse gases is surely making the situation a bit worse, and its impact will undoubtedly escalate when the real warming occurs later in this century.   But today, global warming is a relatively small element of the current wildfire situation, particularly in the slow to warm Pacific Northwest.  As citizens of one small region, there is only so much we can do to stop global warming. But we can fix our forests, improving the fire/smoke situation today and preparing for the greater warming that is undoubtedly in our future.

from Cliff Mass Weather and Climate Blog https://ift.tt/2P4vL9b