Tuesday, March 24, 2015

Ooops! watts posited Anthony? pine beetle and forest fires

Anthony came up with another weird post today, I know.  Using a just released study that claims pine beetle killed forests aren't any more likely to burn than dry healthy forests, he rips Joe Romm for an article he wrote a couple years ago about drying forests, warmer temperatures, and even increased bark beetle infestations, conspiring to increase fire danger as we move forward, and then he tippy toes off stage to let his fans chew on the bones.

"Ooops! Posited pine beetle to increased wildfire risk debunked by CU study"
Anthony Watts / March 24, 2015
It has been posited by paid alarmists like Joe Romm that global warming will increase pine beetle outbreaks, thus increasing the chances of wildfire. For example, in April 2013 Romm wailed:
“…the mountain pine beetle, has already killed 70,000 square miles of trees — area the size of Washington state. As winters become milder, weather becomes drier and higher elevations become warmer, bark beetles are able to thrive and extend their ranges northward. 
An increase in some species of bark beetle can actually increase the risk of forest fires in areas affected by the beetle — the study notes an outbreak of the mountain pine bark beetle, which attacks and kills live trees, created a “perfect storm” in 2006 in Washington, where affected lodgepole pines burned “with exceptionally high intensity.” 
From the University of Colorado at Boulder: 
"Western forests decimated by pine beetles not more likely to burn" (see the bottom for quotes from this study)

Anthony, nor is it any less likely to burn! 
Bark beetle infestations are continuing to decimate healthy forests throughout the world.
Temperatures continue to increase.
Watersheds continue drying out.
Fire danger continues rising.

Anthony, how is that study supposed to change any of that?  What's with the weird glee?
Instead of always battering "alarmists" - why never show any interest in learning about the substance of these issues?
"It has been posited by paid alarmists like Joe Romm that global warming will increase pine beetle outbreaks, thus increasing the chances of wildfire."
Look at Joe's article you'll see that heat and drying are front and center, bark beetle infestations are simply another piece of the malaise.

Nothing about that equation has changed Anthony, what's your point?  

What does it matter that overall, one study can't find a big difference in past fire patterns?  Besides, reflecting on yesterday's world as this study does is fine for establishing a baseline for later comparison, but it's no predictor for forest fire dynamics in the brave new warming world we are entering.
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Here's the beginning of the paragraph to the sentences Anthony quotes above. 

USDA: Climate Change Will Double Area Burned in Wildfires By 2050
Posted by Joe Romm,  April 5, 2013

"The report also outlines the other effects climate change will have on the forests of the U.S. The Rocky Mountain forests are expected to become hotter and drier as the planet warms, conditions that in addition to wildfires will lead to an increase in infestations of insects such as the bark beetle, which has already destroyed tens of millions of acres of U.S. forests. ..."
~ ~ ~ ~ ~ 
"The report’s findings are in line with previous studies on climate change’s relation to fire risk: a 2012 study found that wildfire burn season is two and a half months longer than it was 40 years ago, and that for every one degree Celsius temperature increase the earth experiences, the area burned in the western U.S. could quadruple. The findings are also in line with the observed impacts climate change is having on wildfires. Wildfires in 2012 burned a record 9.2 million acres in the U.S., and record-breaking heat and dry weather in Australia provided ideal conditions for at least 90 fires that raged through the country this January. ..."

"David Peterson, a U.S. Forest Service biologist who co-authored the report, told the Denver Post that the destruction the bark beetles have inflicted upon western forests in recent years has been unprecedented:
“We’re getting into extreme events that seem to be having more and more effects across broader landscapes.”
Now from 'Anthony's' CU study:

Study: Western forests decimated by pine beetles not more likely to burn
March 23, 2015
Hart, Schoennagle, Veblen

“The bottom line is that forests infested by the mountain pine beetle are not more likely to burn at a regional scale,” said CU-Boulder postdoctoral researcher Sarah Hart, lead study author. “We found that alterations in the forest infested by the mountain pine beetle are not as important in fires as overriding drivers like climate and topography.” 

“I think what is really powerful about our study is its broad scale,” said Hart. “It is pretty conclusive that we are not seeing an increase in areas burned even as we see an increase in the mountain pine beetle outbreaks,” she said.

“These results refute the assumption that increased bark beetle activity has increased area burned,” wrote the researchers in PNAS. “Therefore, policy discussions should focus on societal adaptation to the effect of the underlying drivers: warmer temperatures and increased drought.”
From the actual study:  http://www.pnas.org/content/early/2015/03/18/1424037112.abstract


In the western United States, mountain pine beetles (MPBs) have killed pine trees across 71,000 km2 of forest since the mid-1990s, leading to widespread concern that abundant dead fuels may increase area burned and exacerbate fire behavior. Although stand-level fire behavior models suggest that bark beetle-induced tree mortality increases flammability of stands by changing canopy and forest floor fuels, the actual effect of an MPB outbreak on subsequent wildfire activity remains widely debated. 
To address this knowledge gap, we superimposed areas burned on areas infested by MPBs for the three peak years of wildfire activity since 2002 across the western United States. Here, we show that the observed effect of MPB infestation on the area burned in years of extreme fire appears negligible at broad spatial extents. 
Contrary to the expectation of increased wildfire activity in recently infested red-stage stands, we found no difference between observed area and expected area burned in red-stage or subsequent gray-stage stands during three peak years of wildfire activity, which account for 46% of area burned during the 2002–2013 period. Although MPB infestation and fire activity both independently increased in conjunction with recent warming, our results demonstrate that the annual area burned in the western United States has not increased in direct response to bark beetle activity. Therefore, policy discussions should focus on societal adaptation to the effects of recent increases in wildfire activity related to increased drought severity.

Seems over reaching, not to say adapting to drought conditions shouldn't be top on our list.  And how conclusive should we consider this study before it has a chance to be evaluated by the expert community in light of other studies? 

More important, it's no big surprise that weather is the overriding factor with forest fires.  I've watched the daily temperature arc drive forest fire intensity, on a hot day a couple degrees makes an amazing, a frightening, amount of difference.

Still the bottom line remains that dead forests make for great tinder and they will burn when they are hot and dry!  Figuring out respective percentages seems not so important compared to the reality of the hotter and drier world we are entering.  
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Incidentally, there's an interesting trajectory to the character of fires in beetle kill zones.  First the bark beetle attacks, depending on the tree's vigor it will fight off the infestation or slowly succumb, with death, and slow decomposition of the tree.  

First there's slowly increasing susceptibility to fire.  Then just as the trees die with the needles continuing to dry out, that's the "perfect storm" window - true tinderboxes ready to burst into dramatic blistering "crown fires".
However with a number of seasons the needles and small branches get shorn from the trees and fall, collecting on the ground in thick layers.  At this point crown fire danger drops off dramatically, instead when a fire does get started it tends to be slow moving, and it digs down into the duff.  Such fires can smolder subsurface for a long time and travel large distances and are hard to spot and fight.

Worst, these less dramatic fires travel near the ground and usually sterilize the soil making plant reestablishment and regrowth much more difficult.  

And of course looking into the future we know the heat's going to keep mounting.  As for the Bark Beetle story, it's complex and fascinating:

April 12, 2013
A citizen's review of the "San Juan Bark Beetles and Watersheds Workshop"

May 12, 2013
The changing face of our forests - bark beetle and global warming

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