Yesterday, the New York Times ran a story that was blatantly false, with the Seattle Times featuring it as well.
The claim: that Western Washington will experience more "megafires" due to human-caused global warming (climate change).
Unfortunately, the writer of this story (a Washington State stringer for the NY Times) failed to examine the historical record or the best science, getting the essential facts wrong.
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How do I know the writer got it wrong?
Because for the past two years, I have researched this very issue and just published a paper on this topic in the peer-reviewed literature (here). I have read every paper and report on this issue.
So exactly that did the NY Times (and the Seattle Times) get wrong?
The article defines megafires as ones that involve hundreds of thousands of acres.
How many such fires have occurred since 1900 in western Washington?
ONE. The Yacolt Fire of 1902 (238,000 acres), just north of the Columbia River.
Has there been an increase in the number or size of large western Washington fires during the past 50 years, a period in which the Earth and our region have warmed?
The answer is no, which alone should make one doubt the NY Times claims.
If global warming contributes to big fires, we should be seeing increases in the number of big western Washington fires due to such climate change. We are not.
The reason for this lack of correlation between warming and big local fires is clear.
Big western Washington fires are very different animals from the small localized westside fires, such as the current Bear Gulch fire on the Olympic Peninsula (about 4000 acres now).
To have a "megaburn" burn in western Washington, one needs strong, sustained easterly (winds from the east. No matter what the temperature, no matter what the prior rainfall, without strong easterly winds we do not get westside megafires.
It is very difficult to produce large wildfires in the very moist environment of western Washington forests. Only strong easterly winds make it possible.
How do I know this?
Because in my research (again published), I looked at EVERY large western Washington and Oregon fire of the past 150 years, examining all available weather observations and simulating most of them with a modern high-resolution model (see sample below of near-surface winds for the 1902 Yacolt fire, colors indicate wind speed).
Every one of them was associated with strong easterly flow.
So what does this have to do with climate change and global warming?
It turns out that strong easterly winds are REDUCED in our area under global warming/climate change.
You read that right. The threat of the necessary strong easterly winds is LESSENED by climate change.
I can tell you why.
Anthropogenic (human-caused) global warming is greater in the interior of continents than over the slower-to-warm oceans. Virtually every climate simulation shows this...it is not controversial (see example below from regional climate runs made by my group)
Warm air is less dense than cold air, which results in preferential pressure declines inland than over the slower-to-warm coastal areas.
If pressure falls more inland (where it warms more), then winds tend to move from west to east (air tends to blow from a high-pressure area to a lower-pressure pressure).
Onshore flow like this is just the OPPOSITE of that needed for big western Washington wildfires.
To put it succinctly: the NY Times and Seattle Times not only got the story wrong, they got it REVERSED. Global warming will reduce the potential for western Washington mega-wildfires because the necessary easterly winds are weakened.
The writer of this story did not bother to examine the frequency of local megafires nor understand the meteorology that drives them.
Such sloppy and poorly researched "journalism" misinforms readers and leads to poor decision-making. Very disappointing.
VERY disappointing journalism, I agree. Another example of captured media.
ReplyDeletePlease provide a link to a non-paywalled copy of your research paper
ReplyDelete“Has there been an increase in the number or size of large western Washington fires during the past 50 years, a period in which the Earth and our region have warmed? The answer is no, which alone should make one doubt the NY Times claims.”
ReplyDeleteThis seems like a key claim. Can you show some data to support it? It might be tough given the changes in fire suppression over this period.
jerry....the information is in the blog. There has been only ONE such event since 1900....the 1902 event. There is no fire suppression that can help with such events--with the strong winds the fires are out of control. ..cliff
DeleteCliff is a welcome referee in the ever hyped up, attention seeking media machine.
ReplyDeleteI have a little different take on this article and Cliff's response to it. A large mega fire requires the coming together of these factors: an ignition source, a large fuel bed ready to burn, and strong winds. Absent one of these factors and a large fire will not occur. First off, there may be an increasing number of ignition sources as the population increases. Secondly, what the article points out is that with global warming, the fuel bed may be increasingly ready to burn, as witness the increasing number of smaller fires west of the Cascades in recent years. Thirdly, Cliff may be right that with global warming, the number of east wind episodes will decrease. Not all east wind episodes in the past have resulted in large fires, either because there was no ignition source or fires present then, or the fuel was not dry enough. Now with the possible increase in ignition sources and drier fuel due to global warming, even with fewer east wind episodes, there may be about the same chance for a mega fire as before since the fuel will be more often ready to burn.
ReplyDeleteBut if we have “the increasing number of smaller fires west of the cascades” won’t that help prevent mega fires since the small fires will reduce fuel bed size? Let the small fires burn to clean the floor.
DeleteLazy journalism from the paper of Walter Duranty. Thanks again Cliff.
ReplyDeletewxman.... each year, with normal climatology, you can get the big western fires, IF you can get the strong winds. I looked an antecedent conditions...no pattern. By middle to end of summer the forests will burn if the winds are strong enough..cliff
ReplyDeleteHard to accept that there will be no strong easterly winds in the future during fire season. The modeling seems simplistic and static but it seems the reality is going to be more dynamic with high and low pressure systems interacting dynamically.
ReplyDeleteNo one said no strong easterly winds...but they will be reduced by climate change...which could neutralize the increasing warmth.
DeleteI once found some old maps of the puget sound area (I think from the late 1800s) that showed huge burned areas in eastern king county. I thought it was interesting but never investigated the source of those fires.
ReplyDeleteThere is a very interesting July 28 post (long) in Gig Harbor Now regarding the history of fire and smoke in the Puget Sound area during the late 19th and early 20th century. The gist of the story is that summertime fire and and heavy smoke often did not even make the news because it was so commonplace.
ReplyDeletehttps://www.gigharbornow.org/news/arts-entertainment/gig-harbor-now-and-then-history-of-wildfire-smoke-gig-harbor/
There appeared to be more large fires and smoky days in the late 1800s, early 1900s in the Pacific Northwest, even though based on the weather records existing then, this did not seem to be a period of especially dry seasons, except for a few years such as 1889 and 1910. One does notice from old photos, extensive burned off areas especially near railroad right-of-ways. I believe the extensive burned areas were caused not so much by dry seasons, but by frequent ignitions from the old trains, careless fires from logging operations and clearing fires started by settlers. All of this during a period when there was little or no organized fire suppression.
ReplyDelete