Menus Subscribe Search

‘Deforest Fires’ Fan Global Warming

• April 23, 2009 • 7:06 PM

Deforestation has long been associated with global warming, but a new paper suggests the method of deforesting — intentionally burning — may be a terrifically potent climate changer, too.

Fire looks to be one big contributor to global warming — not directly through its heat, although in some barely discernable way that certainly adds to warmth, but by what it does to the planet’s landscape.

A new study that appeared in the April 24 edition of the magazine Science suggests that as much a fifth of mankind’s carbon dioxide emissions in the industrial era can be traced to intentionally burning down forests. That doesn’t include burning firewood to heat your hut, and it doesn’t count wildfires (even those from arson or controlled burns gone awry).

And those intentional fires help create the feedback loop that fosters unintentional fires like the wildfires that char Australia or the Western U.S. each summer. Beyond the release of carbon dioxide, “landscape fires” of all stripes incinerate carbon-storing plants and pump sunshine-absorbing soot into the global atmosphere.

And so the vicious circle is described thusly: “These deforestation-related fires contribute substantially to the global burden of greenhouse gases, and the associated global warming that they will cause is projected to increase extreme fire weather, leading to further spikes of carbon emissions.”

Despite this, fire really hasn’t factored into comprehensive examinations of climate change, argue the authors of the Science paper — led by David Bowman of the University of Tasmania and Jennifer Balch of the National Center for Ecological Analysis and Synthesis at the University of California, Santa Barbara.

“Progress in understanding fire on Earth has been hampered by cultural aversions to accepting fire as a fundamental global feature and disciplinary parochialism,” they write in calling for a more sophisticated understanding, both technologically and psychologically, of fire’s role in climate change. “… Such an integrated perspective is necessary and timely, given that a diversity of fragmented research programs have identified the pervasive influences of fire on the Earth system.”

“It’s not new information,” Balch said of the paper itself, “but it’s been fragmented. What we’ve done is pull all these threads together to state the obvious.”

Shadow Life Form
A conversation with Bowman suggests the ambitions of the paper — “Fire in the Earth System” — barely fit its four pages of narrative. The work of 22 authors, ranging from physicists, epidemiologists and ecologists to cultural historians, the paper aims to push beyond the “fire community” to present landscape fire into a central  position in the earth sciences — “it demands that we think about its history.”

The phenomenal output of the greenhouse gas carbon dioxide that the paper traces to intentional burning is the hook, Bowman stated bluntly, but the overriding message is that fire has been a “shadow life form” on Earth that predates civilization by 420 million years — when the first plants started popping up on land.

Fire, he said, has been a potent force for evolution ever since. “I like to say ‘fire is the one Darwin dropped,’” Bowman said, reflecting on the naturalist’s visit to fire-configured island of Tasmania on the same trip that landed him on the Galapagos. “He saw everything he needed to see, but he didn’t get it.”

While the ecological landscape in Hobart in Tasmania actually requires routine visits by fire to thrive, the paper suggests the Earth itself evolved in part by growing up alongside fire. “Earth is an intrinsically flammable planet owing to its cover of carbon-rich vegetation, seasonally dry climates, atmospheric oxygen, and widespread lightning and volcano ignitions,” it reads.

As Balch said, “Earth is a fire planet. Fire is what happens when you have carbon burn, an ignition source, and a hot and dry climate. And we are a fire species. But part of what is tricky for people is that we use fire very imperfectly — we don’t control it.”

And so that’s why fire has such a major influence now on accelerating climate change: Humans have unleashed what they thought was something tamed only to discover it remained feral.

Fire has been part of the human toolkit for between 50,000 and 100,000 years, with reliable evidence of at least occasional human use going back hundreds of thousands of years earlier. Once hunter-gathers with fire became agriculturalists with fire, the record shows they started using fire to shape their surroundings, through slash-and-burn efforts, to manage wildlife or to permanently take land from the forests for cities and fields.

“Assuming that deforestation and fire are synonymous — and we do — fire is the cheapest and easiest way to replace forest with pasture or crop land,” said Balch. Those fires produce greenhouse gases and put soot in the atmosphere, but in some cases they also change the land’s reflectiveness — its albedo — from dark forest to brighter snowfields or pastures. In addition, inefficient burning often left lots of carbon still rooted, often literally, in the ground. Some estimates even see the cooling from albedo canceling out the heating from soot in the air.

That canceling out is taken as a given in naturally occurring wildfires, Balch said of the paper’s estimates. “We assume that all other types of fires are in equilibrium. That’s why we focus on deforestation fires, because they are outside the norm.”

The Hard Part
There was also a practical reason to focus on deforestation fires, Bowman said. It was something that could be figured out, even if the effort might prove tortuous. Describing the meeting on fire where the Science paper was born, the idea arose to calculate the contribution fire might be making to the warming of the atmosphere.

Such a calculation, with a billion or so cook fires every night, wildfires, deforestation fires and others in the mix, “would be devilishly complicated for a climate model,” Bowman recalled the thinking. “That’s going to be really, really hard. Maybe we just use deforestation fire.” He summed up the consensus. “Intentional deforestation fire – that is something we do know, a clearly described domain, with an historical certainty and an historical precedent.”

The starting point for the data gathering was the Industrial Revolution, circa 1750, which is also the starting point for many other examinations of greenhouse gases and climate change.

As it stands, the authors estimate that all sources of fire, from hut warming to ginormous peat fires in Indonesia, emit an amount of carbon dioxide equal to half that from the burning fossil fuels, the traditional villain in climate change scenarios.

But lots of unknowns and perhaps unknowables remain, and the authors acknowledge that this paper is but a first stab at the issue, “a first estimate, a crucial step in quantifying and recognizing the issue,” Balch said. “What we are calling for is a complete treatment of fire in the next generation of climate models and an acknowledgement that fire is, and has been, an important actor for a very long time.”

“We all know that climate affects fire,” said Bowman, “but we’re only now realizing that fire affects climate. Fires are blindingly obvious, but their effects on the Earth’s systems (are) deeply subtle, and humans have the interesting possibility that they’re part of the feedback.

“That’s the scary bit, that if we serio
usly disturb that equilibrium … then we have the capacity for feedback. And that plays into the climate projections that we’re using, that we’re debating right now, may, sadly, be an underestimate.”

Sign up for our free e-newsletter.

Are you on Facebook? Become our fan.

Add our news to your site.

Michael Todd
Most of Michael Todd's career has been spent in newspaper journalism, ranging from papers in the Marshall Islands to tiny California farming communities. Before joining the publishing arm of the Miller-McCune Center, he was managing editor of the national magazine Hispanic Business.

More From Michael Todd

A weekly roundup of the best of Pacific Standard and PSmag.com, delivered straight to your inbox.

Recent Posts

July 22 • 8:00 AM

On Vegas Strip, Blackjack Rule Change Is Sleight of Hand

Casino operators are changing blackjack payouts to give the house an even greater advantage. Is this a sign that Vegas is on its way back from the recession, or that the Strip’s biggest players are trying to squeeze some more cash out of visitors before the well runs dry?


July 22 • 6:00 AM

Label Me Confused

How the words on a bag of food create more questions than answers.


July 22 • 5:07 AM

Doubly Victimized: The Shocking Prevalence of Violence Against Homeless Women

An especially vulnerable population is surveyed by researchers.


July 22 • 4:00 AM

New Evidence That Blacks Are Aging Faster Than Whites

A large study finds American blacks are, biologically, three years older than their white chronological counterparts.



July 21 • 4:00 PM

Do You Have to Learn How to Get High?

All drugs are socially constructed.


July 21 • 2:14 PM

The New Weapon Against Disease-Spreading Insects Is Big Data

Computer models that pinpoint the likely locations of mosquitoes and tsetse flies are helping officials target vector control efforts.


July 21 • 2:00 PM

Why Are Obstetricians Among the Top Billers for Group Psychotherapy in Illinois?

Illinois leads the country in group psychotherapy sessions in Medicare, and some top billers aren’t mental health specialists. The state’s Medicaid program has cracked down, but federal officials have not.



July 21 • 12:00 PM

What Makes You So Smart, MacArthur Genius?

Noah Davis talks to Yoky Matsuoka about youth tennis, wanting to be an airhead, and what it’s like to win a Genius Grant.


July 21 • 11:23 AM

People Are Clueless About Placebos

Doctors know that sometimes the best medicine is no medicine at all. But how do patients feel about getting duped into recovery?


July 21 • 10:00 AM

How Small-D Democratic Should Our Political Parties Be?

We need to decide how primaries should work in this country before they get completely out of hand and the voters are left out entirely.


July 21 • 8:00 AM

No, Walking on All 4 Limbs Is Not a Sign of Human ‘Devolution’

New quantitative analysis reveals that people with Uner Tan Syndrome don’t actually walk like primates at all.


July 21 • 6:00 AM

Sequenced in the U.S.A.: A Desperate Town Hands Over Its DNA

The new American economy in three tablespoons of blood, a Walmart gift card, and a former mill town’s DNA.


July 21 • 5:00 AM

Celebrating Independence: Scenes From 59 Days Around the World

While national identities are often used to separate people, a husband-and-wife Facebook photography project aims to build connections.


July 21 • 4:00 AM

Be a Better Person: Take a Walk in the Park

New research from France finds strangers are more helpful if they’ve just strolled through a natural environment.



July 18 • 4:00 PM

The Litany of Problems With the Pentagon’s Effort to Recover MIAs

A draft inspector general report found that the mission lacks basic metrics for how to do the job—and when to end it.


July 18 • 2:00 PM

Sure, the Jobs Are Back, but We Need a Lot More

We’re back to where we were before the 2008 recession, but there are now 12 million more people in the United States.


July 18 • 12:00 PM

What Are the Benefits of Government-Funded Research?

Congress wants to know.


July 18 • 10:31 AM

Why Didn’t California’s Handheld Phone Ban Reduce Motor Accidents?

Are handheld cell phones as dangerous as they have been made out to be?


July 18 • 10:00 AM

The Upside of Economic Downturns: Better Childhood Health

For children, the benefits of being born in tough times can outweigh the costs.


July 18 • 9:48 AM

What Tech Talent Shortage? Microsoft Trims 18,000 Employees From Payroll

Like manufacturing before it, the Innovation Economy has reached a turning point, with jobs moving to places where labor is cheaper.


July 18 • 8:00 AM

The Academic of Comic Books

Kim O’Connor talks to Hillary Chute about comics as objects of criticism, the role of female cartoonists, and the art world’s evolving relationship with the form.


July 18 • 6:00 AM

The Supreme Court’s ‘Hobby Lobby’ Ruling Isn’t a Women’s Health Issue

It’s a private health issue. And it affects us all.


Follow us


Subscribe Now

The New Weapon Against Disease-Spreading Insects Is Big Data

Computer models that pinpoint the likely locations of mosquitoes and tsetse flies are helping officials target vector control efforts.

People Are Clueless About Placebos

Doctors know that sometimes the best medicine is no medicine at all. But how do patients feel about getting duped into recovery?

No, Walking on All 4 Limbs Is Not a Sign of Human ‘Devolution’

New quantitative analysis reveals that people with Uner Tan Syndrome don't actually walk like primates at all.

Why Didn’t California’s Handheld Phone Ban Reduce Motor Accidents?

Are handheld cell phones as dangerous as they have been made out to be?

The Upside of Economic Downturns: Better Childhood Health

For children, the benefits of being born in tough times can outweigh the costs.

The Big One

Today, the United States produces less than two percent of the clothing purchased by Americans. In 1990, it produced nearly 50 percent. July/August 2014

Copyright © 2014 by Pacific Standard and The Miller-McCune Center for Research, Media, and Public Policy. All Rights Reserved.