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The Best Science Writing Online 2012
Showcasing more than fifty of the most provocative, original, and significant online essays from 2011, The Best Science Writing Online 2012 will change the way...
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BOULDER, Colo. – As the West has warmed and dried over the past 30 years, headlines describing fire season have grown ever more apocalyptic: "epic" dryness, "monster" fires, new records for damage and devastation.
This year is no exception. The Waldo Canyon Fire has incinerated hundreds of homes in Colorado Springs, and every indication points to another big, early start to the wildfire season.
Recent research, however, suggests these severe conflagrations could be a prelude. Climate stressors are putting increasing pressure on a "fire deficit" the West has accumulated over the past 100 years, say scientists who have compared today's burn rates with fire activity over thousands of years. As the West continues to warm, that debt will come due – possibly with interest – triggering fires that are fiercer and harder to contain, they warn.
"If you just look at what the current climate is like, the rate of biomass burning should be much higher than what we've observed over the 20th century," said Patrick Bartlein, a climatologist at the University of Oregon and a co-author of the study, published earlier this year in the journal Proceedings of the National Academy of Sciences.
Fire activity for the last 100 years has been remarkably low compared to the past three millennia, Bartlein and his colleagues concluded. Given just how much the West has warmed since the early 1900s, these scientists believe fire should be more common and widespread than it has been.
Fire activity hasn't grown with the warming climate, Bartlein said, because since about 1900 Westerners have worked hard to keep fire out. "This divergence between climate and fire activity is unsustainable," he added. "Eventually, nature will catch up."
In their research, Bartlein and his colleagues used a record of past fire activity obtained from cores of sediments extracted from the bottom of mountain lakes. These sediments contain layers of charcoal particles that fell from smoke plumes or were carried into lakes by streams after wildfires. These bands can be read like a timeline. Combined with other data, they allow scientists to reconstruct 3,000 years of wildfire history in the West.
Overlaying that history on a record of natural climate change, the researchers saw a pattern: More fire when the climate was warmer and drier, such as during the period known as the Medieval Climate Anomaly from about 950 to 1250; less fire during the cool and moist Little Ice Age from 1400 to 1700.
In other words, for most of the past 3,000 years, climate has determined fire activity.
That changed as the 19th century ended. The charcoal record shows that fire activity plummeted – and continued to do so in the 20th century even as a strong signal of global warming from human activities emerged.
Bartlein and his colleagues point to a number of factors for the change, including the introduction of cattle, which reduced fuel loads by eating and trampling grasses; fragmentation of the landscape; and vigorous suppression of any fires on public lands that did break out.
Recent trends suggest the fire deficit is now being paid back. Since the 1980s, fire frequency in the West has increased more than 300 percent, and the annual acreage burned has jumped 500 percent, according to Anthony Westerling of the University of California’s Sierra Nevada Research Institute.
Thomas Veblen, a researcher at the University of Colorado who studies wildfire and climate but who was not involved in the fire debt research, cautions that the broad-brush strokes of the fire deficit picture do not reflect the situation everywhere in the West and in all mountain ecosystems. "It aggregates data over an enormous area," he said.
There are, for example, significant differences in fire behavior between the naturally open, grassy ponderosa forests common in the foothills of the Rockies, and the denser Douglas fir and lodge pole pine forests higher up. These differences – key to managing wildfire risks – are not captured by the fire deficit research.
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10 Comments
Add CommentMay?? Sometimes you just want to say "duh".
Reply | Report Abuse | Link to thisFolks get caught up in an event and it clouds perspective. Wild fires in the Western USA are BELOW the norms for this time of year (announced by the US Forest Service today). Wild fires in western Canada are at almost historic lows.
Reply | Report Abuse | Link to thisFires in forested regions are common, needed and part of the natural order. That much is true. The problem, increasingly, is the human biomass that is expanding into these areas and who are suffering as a result. Ninety to one hundred percent of the problems humankind face on earth are due to humankind and the bio-diverse imbalance we represent as a species.
Reply | Report Abuse | Link to thisThe article scores highlighting the 20th century anomaly related to human-driven re-arrangements. But it also underscores the long-term partnership of heat/dry to fires. Trying to escape the relationship and trend with any dismissive about 'so far this year' is practicing a three-monkeys attitude.
Reply | Report Abuse | Link to thisThat's how science works.
Reply | Report Abuse | Link to thisWe don't know evolution is real because Charles Darwin said so. We know it because thousands of researchers over 150 years independently studied it.
People always use the argument of "it's just one study..." to dismiss claims with which they disagree. So scientists conduct multiple studies to increase robustness and strengthen the chain of evidence.
For the people who seem to have a downer on science...read the article before jumping on your OLD bandwagon. The research is linking todays warming with historical evidence and what this means for predicting fire behaviour. To my mind the very essence of what science is.
Reply | Report Abuse | Link to this1. Many 20th century fires were human caused.
Reply | Report Abuse | Link to this2. Were we ever really that good at fire suppression?
3. And isn't the fire fighting being done now fire suppression?
Of course, natural disasters such as fire are necessary for the development and succession of forests. And I agree that society shouldn't worry about it, unless it puts people's lives in danger.
Reply | Report Abuse | Link to thisDennis has a good point. It is unlikely that a Renaissance man burned down the forest with a cigarette, so data is definitely skewed based on a variety of variables including human behavior.
Comparing the virgin forests of the past 3,000 years to the present day forests in this country is just another apples and oranges comparison.
Reply | Report Abuse | Link to thisOf course there is less acres of forest burning lately. There is less forest and much of it is crisscrossed with highways and man made fire breaks that make it easy to control fires when they are small.
Much of our forests land has already been thinned out and many thousands of people are employed in the business of making sure the rest of us don't burn our heritage down.
Millions of hectors of forest land are now occupied by private homes all of whom have a vested interest in preventing nature from grooming herself. Millions more were converted to farm land which are irrigated and kept clear of weeds and brush that fuel wild fires.
What all this has done, especially in recent years, is create a huge tinder box of under brush and beetle damaged trees that creates the reality that it is not a matter of if a fire will burn the forests down, but when.
Climate change is the great equalizer. Nature has no plan, just action and reaction. Until humans collectively figure this out and put the brakes on unchecked development and the resultant pollution, there is nowhere to go but up in smoke.
Aussie firm seeks donations to launch predictive virtual 3d earth fire mapping mobile app http://www.indiegogo.com/projects/192919?a=746377 check this out, if your concerned about fires, this app may save your life
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