The Waldo Canyon fire raging on the western edge of Colorado Springs has riveted my attention in the last few days. It is but one of many in Colorado this year, though uncomfortably close to yours truly, and right next door to the home of a close friend. One question unasked in the non-stop local media coverage is the effect of climate change on fire-prone regions, a topic explored in a recent study by researchers at UC Berkeley and Texas Tech. The following extract, from a piece by Nathanael Massey at Climate Wire, gives the unnerving details.
Although no single fire, no matter
how severe, can be concretely linked to global climate change, the climatic
conditions seen in Colorado this year fit the kind of pattern scientists expect
to see in the future.
In one of the most comprehensive
fire-modeling studies to date, researchers from the University of California,
Berkeley, and Texas Tech University aggregated 16 separate climate models to
map future fire-prone regions of the globe.
Their findings suggest that, in the
decades to come, fire prevalence will decrease in tropical regions -- but will
increase, possibly severely, at more northerly latitudes, and particularly in
the western United States.
"In next 30 years, we're
looking at pretty consistent disruption of current fire patterns for over half
the planet -- most of which involve increases" in severity, said lead
author Max Moritz, a fire specialist based at UC Berkeley's College of Natural
Resources.
Toward the end of the century, he
said, an increased prevalence of fire becomes a near certainty for most of the
Northern Hemisphere.
Modeling future climate scenarios
is a notoriously tricky science, involving wide margins of uncertainty, myriad
variables and a profusion of data. To improve accuracy, Moritz's team looked
for commonalities among 16 models and produced their own projections of the
results.
With this new, aggregate climate
map in hand, they turned to a technique used primarily by ecologists and
biologists, called species distribution modeling, to identify fire-prone
regions of the globe.
When modelers want to predict the
future movement of a particular species, they first establish a set of
conditions -- in terms of climate, soil quality and other variables -- under
which that species is likely to thrive. Examining future climate projections
over a large area, they can identify regions where such conditions are likely
to arise, drawing the species to them as they do so.
The researchers realized they could
apply the same science to fire. "Basically, we looked at fire as an
organism," said Moritz. "We asked ourselves, 'What are its habitat
requirements? What are the conditions under which fire's going to
thrive?'"
Fire prevalence would intensify in
regions characterized by two factors, they decided -- an abundance of fuel and
long, dry summers. They looked to their models to determine where this
"perfect storm" might come together and found that, by the end of the
century, almost all of North America and most of Europe would likely see a jump
in the frequency of wildfires.
Tropical regions, despite holding
an abundance of fuel, would see their dry season decline, lessening their
chances for severe burns.
Given those trends, human beings
will need to adjust their approach to fire management, said Moritz.
Fire has always been an integral
part of the ecology of the western United States, a force of destruction but
also of renewal. Periodic wildfires clear old growth, curb beetle kill and even
aid in the propagation of certain plant species whose seeds can be released
only under extreme heat.
Humans, on the other hand, have
generally opted to obstruct the cycle rather than coexist with it. And that has
had some unintended consequences.
Fire suppression throughout much of
the 20th century allowed fuel to accumulate, leading to a sharp uptick in
severe, extensive burns in the 1980s and 1990s.
Since then, forest managers have
begun to adopt "controlled burn" regimes, in which fires are
intentionally set in areas judged to need them.
If Moritz's projections are
correct, however, efforts to control seasonal fires -- through both suppression
and pre-emption -- will need to be scaled up in tandem with increased fire
prevalence.
Those efforts are progressing, if
slowly. The U.S. Forest Service announced yesterday that it has contracted for
seven new "next generation" air tankers for wildfire suppression,
part of the service's ongoing efforts to replace its current, aging fleet.
Nathanael Massey, “As
Wildfires Rage in U.S. West, Scientists Predict Worse Blazes in Future,” Climate Wire, June 14, 2012, via Scientific American.
The above image is from krdo.com, the website of a Colorado Springs TV station.
