Misc. Mental Musings
Widespread Wildfires
S. G. Lacey
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WOW:
The West Coast of the United States is burning. Again.
This seems to be a reoccurring summer phenomenon in recent years. Now, it’s extending into the fall. But what is the cause?
Higher average daily temperatures. Residential areas expanding into the wilderness. Elongated stints of drought. Amplified national news coverage. All of these factors play a part, but each is nuanced.
Only time will tell if this increased prevalence of fires nationally is an anomaly, or an adaptation. Looking at the historical data can give us insight into the future.
Currently, the analytical trends since the start of the 21st century don’t look promising. [REF]
WHAT:
A wildfire is simply defined as uncontrolled burning of natural vegetation. Such events occur around the globe, effecting all manner of ecosystems and climates. In the past, wildfires have predominantly been caused weather events, like lightning and volcanos, and typically impacted remote, and occasionally rural, areas.
Planet Earth is inherently prone to fire, due to the prevalence of carbon-based vegetation, and the abundance of oxygen in the atmosphere. Based on fossil records, these burning events have been occurring worldwide at various scale for over 400 billion years.
In recent years, especially on the western side of the United States, the source, scope, and scale of forest fires seems to be changing. Is this due to the ebb and flow characteristic of many natural phenomenon, like seasonal hurricane prevalence, and winter mountain snow totals? Or, is there something more sinister and persistent afoot?
Wildfires can be classified into 3 categories, based on the type of material they consume. Ground fires actually ignite organic matter within the soil, allowing them to retain heat, and smolder for long periods of time. Surface fires, these most common format, rapidly consume low-lying, often dry, vegetation, like scrub brush and grasslands. Lastly, crown fires simply scorch the tops of trees, traveling with the aid of wind through the leafy forest canopy. [REF]
In many cases, multiple types of fires can occur at the same site through flame transfer mechanisms. Heat can be transmitted from the ground to the surface through roots, then from the surface to the canopy through vines. Fire has a tendency to grow and proliferate once it gets going.
The properties of a ranging wildfire are both impressive, and terrifying. Many of these occurrences start small, requiring only 3 inputs: combustive material, adequate oxygen supply, and a single spark.
Only a small percentage of the natural occurring wildfires are even known to humans in real time, and a minute subset of these discovered ignitions turn into substantial blazes. But those that do explode, garner a vast majority of resources, from both a publicity, and management, standpoint.
The progression of burning which occurs are the front of a forest fire is well-researched, and not dissimilar to the thermal activity in a home fireplace.
Once the air temperature exceeds 100°C, water molecules within the trees start to vaporize. At 230°C, flammable gases in the wood are released through pyrolysis, with smoky smoldering at 380°C, and complete ignition at 590°C. The wall of warm air preceding a large fire can exceed 800°C, promoting faster spread through combustive flashover. [REF]
The forward rate of spread, or FROS, is a key metric for monitoring wildfire movement. This leading edge of destruction can move quite rapidly, up to 10 mph. And this is just one of a raging blaze’s many offensive tools. Like an army, a fire can engage in a flanking maneuver, while simultaneously tracking backwards from the ignition point.
Unlike traditional military forces, as a wildfire extends its scope of battle, it strengthens and grows, rather than being spread thin, from a resource standpoint.
The other trick up a fire’s sleeve is an aerial assault. Moving in a steady, linear, plodding, path is the most common burn trajectory. However, in high wind scenarios, hot embers can be deposited up to 12 miles away from the source. This new spark creates another nucleation site, usually in similarly fragile and combustive vegetation, which can combine with, or even exceed the original blaze in scope.
All these factors conspire to make wildfires very difficult to contain, once a critical mass is reached.
2020 was one of the worst years on record for worldwide fire damage. The United States was hit quite hard, with the states of California, Washington, Oregon, and Colorado feeling the brunt of the damage. Unfortunately, 2021 is continuing the trend of rampant burning, with several months still to go. [REF]
WHERE:
The 2021 Dixie Fire in Northern California is an exemplar of the current challenges in the western US. Starting in mid-July, it burned over 850k acres in the first 3 months, and destroyed hundreds of physical structures.
Now 95% contained, but still smoldering away in many spots, this is the 2nd largest fire by size in the history of the embattled state. Informatively, the remainder of the top 5 all occurred during the 2020 calendar year.
The Bay Area Fire of 2020 was a true monster. Somewhat of a misnomer, based on the origin point, this September fire ended up quickly spreading to Washington and Oregon. Engulfing over a million total acres, and killing 35 people, at its peak, this blaze was swallowing up land equivalent to the city of Washington, DC. Every day.
In terms of financial toll, it’s hard to top the infamous Camp Fire, which started on November 8th, 2018. Raging through a relatively developed area, this blaze torched nearly 20k homes, wiped the unfortunately named town of Paradise, CA completely off the map, and caused 85 casualties. This was one of the most publicized, and most invasive, wildfires ever to impact developed society. [REF]
Albeit, forest fires in the United States are not just a modern phenomenon.
October 1871 was the most aggressive month of burning in the history of the country. The Peshtigo Fire in Wisconsin destroyed 1.2 million acres of forest and farmland, killing over 2,000 residents in the process, the most casualties for any single wildfire event.
This disaster occurred concurrently with the two other, more notable, “Great” fires in Michigan and Chicago. These urban events were much more damaging from a property standpoint, and conspired to result in the most disastrous month of widespread fire damage in American to this day. [REF]
Regardless of the lax building construction techniques, and limited firefighting technology, of this bygone era, it’s clear that environmental conditions like stifling heat, and high winds, are a major driver of fire proliferation.
These days, insurance companies are finally becoming wise to the risks of wildfires, thus starting to require supplemental policies in high-risk regions. The heat map below uses likelihood of a wildfire starting, opportunity for intensification, and potential home damage, to come up with a composite risk score. [REF]
While this information is well known within the industry, unfortunately, there’s a large segment of homebuyers who are completely oblivious to the risks associated with their seemingly beautiful, rural, mountain property.
WHEN:
Counterintuitively, stormy weather often promotes, rather than dampens, forest fires. While the rain helps to moisten the vegetation, lightning strikes are a primary source of fire ignition. Also, the heavy winds associated with a storm front are the primary culprit fanning the flames, thus spreading the scope of the inflicted area.
There’s no debating that the decade long drought across the Sierra Nevada Mountain range has primed the landscape for the devastating fires which have occurred in recent years. Lack of rain, combined with above average temperatures, has created a tinderbox of dead, dry, wood, which is a perfect fire fuel source. [REF]
Research shows that brief periods of heavy rain, which spurs rapid vegetation growth, then a prolonged period of drought, which dries out the underbrush, creates the most dangerous conditions for large wildfires. The recent trends of intermittent heavy precipitation, and very low relative humidity, across the western half of North America, has created a perfect storm.
There are many seasonal elements associated with wildfires, beyond the simple warm, dry, summer climate considerations.
Global warming has led to rapid spring mountain snowmelt, reducing river flow rates, and more rapid drying of topsoil. Alaska, with rocky, glacier-covered, peaks, and average temperatures increasing at twice the rate of the contagious US, is a scary proxy for what could happen in the Rocky and Sierra Mountain ranges in coming decades.
During the past decade of summers, the state of Alaska has frequently amassed over 2 million acres of burning timberland annually, well above the long-term average for this arctic region.
The western half of the country is not the only region prone to burning. The southeastern, heavily wooded, portion of the country, also has some issues.
Tree pathogens like hemlock wooly adelgid, emerald ash borer, and chestnut blight, have resulted in more deadfall as a fire fuel. In an effort to get ahead of this potential inferno, states throughout the Appalachian Range have taken a much more proactive measures than their counterparts on the other side of the Mississippi River, with regards to regular, controlled, burns. [REF]
As shown in the following grid, peak wildfire season across the United States occurs between June and August, with the maximum month for acreage burn falling in this range every year between 1992 and 2015, except 2011. [REF]
Historically, the winter has been a slow time for wildfires in the US. Unfortunately, the large California blazes which initiated in November during 2018 and 2020 seem to be bucking this historical trend. We’ll have to see what happens in this volatile state as the 2021 calendar year rolls over.
WHO:
There’s a group of unsung heroes battling these increasingly prevalent wildfires, which continue to crop up across the nation. These seasonal, mobile, firefighters are commonly referred to as “hot shots”.
The job is grueling, with all manner of non-traditional employment skills needed. Cutting firebreaks across smoldering brush by hand. Hiking daily half marathons over mountainous terrain with 50-pound packs. Sleeping when, and where, you can, over a grueling 5-month season of perpetual reactivity.
A hot shots role is half lumberjack, half Prometheus.
Like seemingly all jobs these days, fire crews are having trouble retaining employees. Considering the brutal conditions they face on a daily basis, no one can blame them. With a starting pay of $13.50 per hour, for U.S. Forest Service workers, while putting their lives at risk on a daily basis, the trade-off is no longer making less sense for many. [REF]
This is a grueling job, with lifelong effects on the body. An increasing number of participants are realizing the risks aren’t worth the reward. This exodus leaves hot shot crews, which typically rely on 20+, well-trained, close-knit, members, desperately short-staffed, while each fire season continues to be more brutal in both size and scope.
There are all manner of factors which hot shots must consider in their daily battles. Geography can often be used as a tool for slowing wildfire spread, relying on a river, roadway, or rocky outcrop as a fire break. However, in hilly terrain, fires can spread very rapidly uphill, especially when winds from below conspire to fan the flames.
Predictably, burn rates are based on sunlight, with the midday heat, then afternoon winds, reigniting, then powering, ongoing blazes. To combat this, the perpetual 24-7 efforts of hot shots use 10AM as a starting point, when the crew is the freshest, and preemptively ready for the multitude of flare-ups which are likely to occur.
Another interesting character in the US wildfire saga is one who was invented. A big, friendly, brown bear, with a tan ranger’s hat, and a consistent message.
“Only you can prevent forest fires.”
While national wildfire mitigation efforts started in the early 1900’s, Smokey the Bear wasn’t conceived until 1944. The surprising motivation was to minimize forest fires domestically, thereby allowing all resources to be devoted to America’s war efforts across the Atlantic. In hindsight, this cute and cleaver creature may be too effective for his blue jeans. [REF]
While campfire safety was, and remains to be, an important preaching, decades of strict mitigation, with any fires which did materialize rapidly being put out, has resulted in a massive buildup of dry deadfall. Maybe it’s time for Smokey to change his tune.
By continuing to put out small blazes, and not allowing natural burning to run its course, in many areas forest floor thick underbrush and downed debris has piled up for decades. Now, in this recent stint of drought across the southwest, many regions are primed for huge, volatile wildfire events.
Modern research has suggested that alternative fire mitigation methods might be the answer. Recent changes in forest management techniques are leading to more controlled burns, to minimize the build-up of risky debris. These practices align with the methods used by Indigenous Peoples for centuries, before residential housing development inundated many of these high-risk regions, especially in California. [REF]
Maybe it’s time to focus more on the human and housing tolls, rather than considering only on hectares decimated.
WHY:
In addition to the traditional known natural causes of wildfires, there’s an almost unlimited number of human induced fire-starting mechanisms. Some of these are accidental, others deliberate, a few even nefarious.
Sparks from a chainsaw blade against a rock. Ignition from a live downed power line. An errant firework, or a casually discarded cigarette. Slash and burn techniques used to rapidly clearing fields for planting. Outright arson. All these methods contribute to the annual wildfire tally around the globe.
Experts estimate that over 85% of wildfires are now initiated by human activity. Like many elements of the natural world, humanity is having an increasingly large impact.
While climate change many be the cause of these larger, more devastating wildfires, ironically, some blazes have gotten so large that they are now influencing the weather. Massive temperature and humidity gradients between the ground-level and higher-altitude air, create winds which can reach 200 mph. Thus, the rare, but recently popularized, fire tornado is created.
There is another important climate contribution from forest fires. These blazes, ravaging though all manner of organic material, release large amounts of carbon dioxide into the air, along with other volatile compounds like nitrogen oxides.
Since 1900, wildfires have accounted for roughly 20% of all global carbon emissions. In 2020, with an abnormally busy forest fire season in California, atmospheric CO2 contributions from smoke exceeded 30% of the carbon dioxide generated through all fossil fuel consumption for the state’s 40 million residents. [REF]
Despite the seemingly catastrophic impact of wildfires of humans, these events actually serve as a critical survival role for many other species on Planet Earth.
Chaparral plants, like the manzanita and scrub oak, require fire to germinate their seeds. Mountain pine trees, such as the bristlecone, use the heat to open up their hearty, serotinous, cones. Leaves of some flora contain a resinous, flammable, oil, which is actual meant to fuel a fire’s spread, and thus the scope of the plant’s potential for sprouting after the burn. [REF]
In all these cases, a raging fire is the key to release and distribute the valuable seeds, which allows for future generations of each vegetation type. Without regular burns, sometimes required as frequently as every 5 years, these species will not be able to reproduce and thrive.
Impressively, plants are not the only biological actor to benefit from forest fires. In Australia, there are several known species of clever birds, including kites and falcons, which will pick up burning sticks, and carry them across manmade fire breaks, in an effort to flush out prey from the brush. Savvy predators indeed.
Unlike humans, who are entrenched in their homes, with numerous possessions, most animals have a collection of innate skills for surviving wildfires, honed over centuries of evolutionary experiences.
Burrowing deep into the earth. Using sheer speed to outrun the heat. Finding a protective body of water. Retreating to barren high ground.
Life will find a way.
A wildfire burn can have a cleansing effect on the landscape, clearing dead leaves and debris, thus allowing new green shoots to sprout. While seemingly damaging, the fire’s relentless destruction can clear out invasive insects, and disease-ridden foliage, thus resetting the ecosystem back to its natural, healthy, state. [REF]
In fact, these recovery zones, known as complex early seral forest habitats, exhibit higher biodiversity and range of species, than the established old growth timberlands which they often displace.
WELL:
While this exploration has focused primarily on the United States, wildfires are currently a global issue. The Amazon rainforest across South America is burning. The Siberian taiga in the Arctic is shrinking. The brushland of Australia is being converted to desert. [REF]
There’s no doubt that throughout North America, the impact of recent, prevalent, forest fires has been devastating, not just to those residents who unfortunately lost their homes, or lives, but also the numerous farmers and ranchers, who previously relied on this now scorched earth for their livelihood.
There are also health and safety considerations, not just for individuals immediately adjacent to the burning fires, but potentially nationally, on account of the smoke and toxins dispersed into the air, with widespread transfer via shifting winds.
Still, the outlook is not all doom and gloom. We’re slowly learning more about the importance of regular wilderness cleansing, and the opportunity for regrowth it can provide. Our civilization has been dealing with wildfires for several millennium. Maybe we just need to look back to the teachings of our ancestors.
WATCH:
Live US wildfire tracking in real time. [REF]
Background on the historic and devastating 2020 California wildfire season, with many compelling pictures. [REF]
Interactive fire and smoke map of the entire United States. [REF]
Documentary film about the Granite Mountain Hot Shots crew, which was unfortunately wiped out in a 2013 fire. [REF]
A bunch of vivid and engaging wildfire infographics. [REF]