Wildfires projected to worsen with climate change

Wildfires projected to worsen with climate change
A fire burns in Sequoia & Kings National Park, Calif., in 2005. Research by environmental scientists at Harvard University predicts wildfire seasons by 2050 will be three weeks longer, up to twice as smoky, and will burn a wider area in the western United States. Credit: National Park Service/Parker Bevington.

Research by environmental scientists at the Harvard School of Engineering and Applied Sciences (SEAS) brings bad news to the western United States, where firefighters are currently battling dozens of fires in at least 11 states.

The Harvard team's study suggests wildfire seasons by 2050 will be about three weeks longer, up to twice as smoky, and will burn a wider area in the western states. The findings are based on a set of internationally recognized , decades of historical , and records of past .

The results will be published in the October 2013 issue of Atmospheric Environment and are available in advance online.

Awareness is building that gradual may contribute in the coming years to increases in significant, disruptive events like and floods. Loretta J. Mickley, a senior research fellow in at Harvard SEAS and coauthor of the new study, is thinking one step further, to secondary effects like and air quality that rely heavily on meteorological factors.

"We weren't altogether certain what we would find when we started this project," Mickley says. "In the future atmosphere we expect warmer temperatures, which are conducive to fires, but it's not apparent what the rainfall or relative humidity will do. Warmer air can hold more water vapor, for instance, but what does this mean for fires?"

"It turns out that, for the western United States, the biggest driver for fires in the future is temperature, and that result appears robust across models," Mickley adds. "When you get a large over time, as we are seeing, and little change in rainfall, fires will increase in size."

Reaching that conclusion with statistical confidence required months of analysis, because at the local level, wildfires are very difficult to predict.

Wildfires projected to worsen with climate change
Organic carbon is one component of smoke from wildfires. Overall, wildfires in 2050 are expected to be up to twice as smoky, threatening visibility and public health. Credit: Xu Yue.

"Wildfires are triggered by one set of influences—mainly human activity and lightning—but they grow and spread according to a completely different range of influences that are heavily dependent on the weather," says lead author Xu Yue. "Of course, when all the factors come together just right—whoosh, there's a big fire."

By examining records of past weather conditions and wildfires, the team found that the main factors influencing the spread of fires vary from region to region. In the Rocky Mountain Forest, for example, the best predictor of wildfire area in a given year is the amount of moisture in the forest floor, which depends on the temperature, rainfall, and relative humidity that season. In the Great Basin region, different factors apply. There, the area burned is influenced by the relative humidity in the previous year, which promotes fuel growth. Yue, who was a postdoctoral fellow at Harvard SEAS and is now at Yale University, created mathematical models that closely link these types of variables—seasonal temperatures, , the amount of dry fuel and so forth—with the observed wildfire outcomes for six "ecoregions" in the West.

After developing those models, the team replaced the historical observations with data based on the conclusions of the fourth Intergovernmental Panel on Climate Change (IPCC), which use socioeconomic scenarios to predict possible future atmospheric and climatological conditions. For this study, the Harvard group followed the A1B scenario, which considers the climatological effect of a fast-growing global economy relying on a mixture of fossil fuels and renewable energy sources. By running the IPCC's climate data for the year 2050 through their own fire prediction models, the Harvard team was able to calculate the area burned for each ecoregion at midcentury.

For example, the calculations suggest the following for 2050 in the western United States, in comparison to present-day conditions:

  • The area burned in the month of August could increase by 65% in the Pacific Northwest, and could nearly double in the Eastern Rocky Mountains/Great Plains regions and quadruple in the Rocky Mountains Forest region.
  • The probability of large fires could increase by factors of 2-3.
  • The start date for the fire season could be earlier (late April instead of mid-May), and the end date could be later (mid-October instead of early October).

Air quality is also projected to suffer as a result of these larger, longer-lasting wildfires. Smoke from wildfires is composed of organic and black carbon particles and can impede visibility and cause respiratory problems. The U.S. Forest Service keeps a record of the amount of fuel (biomass) available across the entire United States, and another set of databases known as the Landscape Fire and Resource Management Planning Tools tracks specific types of vegetation for each square kilometer of land. Based on this information and known emission factors for combustion, the researchers predict that smoke will increase 20-100% by the 2050s, depending on the region and the type of particle.

The main innovation of the new study is its reliance on an ensemble of climate models, rather than just one or two. One of the greatest uncertainties in the science of climate change is the sensitivity of surface temperatures to rising levels of greenhouse gases.

Wildfires projected to worsen with climate change
The area burned by wildfires is expected to increase by 2050, according to research by environmental scientists at Harvard University. Credit: Xu Yue.

"Our use of a multi-model ensemble increases confidence in our results," says principal investigator Jennifer A. Logan, a recently retired Senior Research Fellow at Harvard SEAS.

The fire prediction model developed by the team performed least well in central and southern California, where the rugged topography results in a patchwork of ecoregions, each with a different fire response to changing meteorology. The authors have been investigating the unusual factors at play in that state and expect to release their findings shortly.

For Harvard's atmospheric scientists, the ultimate goal of this project was to see how air quality could be affected by climate change, given that smoke from wildfires is a major source of particulate matter in the atmosphere.

Air quality has vastly improved over much of the United States in the past 40 years, as a result of government efforts to regulate emissions. Mickley warns that increasing wildfires may erase some of the progress.

"I think what people need to realize is that embedded in those curves showing the tiny temperature increases year after year are more extreme events that can be quite serious," she says. "It doesn't bode well."

Explore further

Extreme wildfires likely fueled by climate change

More information: www.sciencedirect.com/science/ … ii/S1352231013004573
Journal information: Atmospheric Environment

Provided by Harvard University
Citation: Wildfires projected to worsen with climate change (2013, August 28) retrieved 20 July 2019 from https://phys.org/news/2013-08-wildfires-worsen-climate.html
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Aug 28, 2013
F*N morons

Aug 28, 2013
Smear campaigners claim skeptics get their facts from Limbaugh, but Rush reveals the true state of affairs, that he gets *his* facts from skeptics, not the other way around:


So far science savvy skeptics are handling this "curious bedfellow" process pretty well so that the ten thousand word straw man argument smear sites that claim to reveal the folly of skeptics fail to hit the mark since seasoned skeptics are quite careful about keeping our core argument tidy instead of scattershot.

Extreme weather trends in the US where the best data exists actually shows the exact opposite of what both US politicians and US media outlets claim for it. That's not just a lie but it's a classic "big lie."

Obama = lowest hurricane count of all presidents.

Buy new BS detector batteries!

Aug 28, 2013
"...the biggest driver for fires in the future is temperature, and that result appears robust across models...."

Do models include environmental lobbying to avoid clearing underbrush while new homes in wildfire territory means we now put out the fires that used to naturally clear it?

Wikipedia: "The Healthy Forests Initiative...is a law originally proposed by President George W. Bush in response to the widespread forest fires during the summer of 2002. The main thrusts of the law are to thin overstocked stands, clear away vegetation and trees to create shaded fuel breaks, provide funding and guidance to reduce or eliminate hazardous fuels.... Much of the basis for the law revolves around the overcrowding of forests due to the suppression of low intensity fires, which vary in their natural role of thinning small trees and clearing vegetative debris."

Aug 28, 2013
And also Global Climate Change make people more aggressive and sets "unprecedented" fire in a National Park!
It never happened before!
OH this is NOT Eco-Fascism no!
Tis si pure Science...

Aug 28, 2013
Agenda 21...Create Global Problems to control Locally...
Scare people so they abdicate from their rights on behalf of the "threatened" planet...
OMG, we are killing the planet!
What a pile of crap...and there comes those naïve people that BELIVE on this...
I am very sorry for them because they are 90% very good people with no agenda behind their beliefs but brain washed unfortunately.

Aug 28, 2013
We have this problem since man has inhabited Australia.
We use to send very well trained fire fighters to help USA.
In fact we know better about this problem that our "allies"...
One very point that should be highlighted here is: research has found conclusive evidence that preventing small fires along the years in those regions that have been experiencing bush fires for millennia causes a very undesirable effect.
When a fire starts it is huge because there was an accumulating fuels left behind by preventing small ones to clean small areas.
In sum, we prevent small fires to occur but this only increase the chance of having big ones latter.
Nothing to do with bloody AGW!
It is cyclic as the Ice ages.
natural cycles... that man cannot interfere.

Aug 29, 2013
This story is just another one of 10s of thousands more fact based scientifically derived reports that AGW deniers can stew over. You know it sucks to be you guys having to live with your denier foolishness. So you guys believe in Unicorns or what?

Aug 29, 2013
Shh... Howhot, this is fascinating. Here we have two bulls posting screeds in the same territory, ones normally not given to pack tactics.

It's difficult to tell whether or not they will back-slap (acknowledgement and ceremonial competition at most) or the one that considers themselves the silverback will attempt to out-outrage the other.

I'd say it's challenge, because Nik's two posts were followed by three by GuruShabu - and considering the three minute forced cooldown...

Let's watch!

Aug 29, 2013
@ GuruShabu; I think that is the first time I've seen anyone mention Agenda 21 on this site. I wonder how many other subscribers are aware of the program? Plus given the legislative climate in California, from what I remember, leads to higher numbers of more destructive wildfires. I'm not certain if the same is for other states. It's similar to how the behavior of people change in regards to the federal gov'ts flood insurance program. It shouldn't come a wonder why there is more of a prevalence of flooding as the taxpayers will flip the bill. To add to the insult, AGW supports claim the increased flooding occurrence to due to climate change or whatever the "flavor of the moment" name it's called now.

Aug 29, 2013
Reply to Goodlmp:
I couldn't agree more.
Most of the answers here are focused in the punctual article but miss completely the big picture. And the big picture is not only AGW is not occurring but it is being used to manipulate the entire poulation of the planet towards what has been set in 1968 by the Club of Rome (http://www.youtub...BAX0E0). It was officially accepted by the USA and more than 100 others countries in 1992 in Rio de Janeiro where G.W. Bush signed the document. After that Bill Clinton has committed to implement its rules and now Obama has already started in 16% of the USA.
Unfortunately, the appeal is so intense that most of people lose their reason and start fighting without even questioning the entire subject. You can see the passion here as everybody receives either 5 or 1 star...:) and it is absolutely delightful receiving a comment such as yours.
We are all going towards a Global Government abdicating our liberties but we not even realise it. Best!

Aug 29, 2013
[Having staked his territory, the rival bull now proceeds to preen and tramp the ground. Assembling a harem has begun.]

Aug 30, 2013
RSS Flat For 200 Months (Now Includes July Data)

35 Inconvenient Truths on Al Gore's Movie (a PDF file) please download it and READ it!

Aug 30, 2013
You are a believer.
I just checked your profile in Physorg.
You are one of the believers on Dark Matter and Dark Energy, one of the biggest blunders of contemporary physics.
Please don't be offended but DM and DE are ad hoc theories. Something you invent to explain something you don't understand and you cannot explain by the present theories.
Presently, we cannot explain why the stars swirl so fast around the centre of galaxies so we add more "stuff" -dark matter- that has no physical properties but the right gravitational pull.
Go to the Perimeter Institute of Theoretical Physics (http://www.perime...ute.ca/) on Cosmology -Lee Smolin).
Read his book The Trouble with Physics - http://www.amazon...1891868X
Believing is blind adherence to something we do nor understand.
We, as good detectives should be sceptical. Check everything we are told and read.
Do not accept a priori without double checking.
All the best to everyone.

Aug 30, 2013
We have this problem since man has inhabited Australia.

Yeah, well, come back and comment during the summer months, when there's an increase in bushfires. And they do seem to be getting worse over the years.

Scare people so they abdicate from their rights on behalf of the "threatened" planet... OMG, we are killing the planet!

Spoken like a true idiot. We are killing the planet.

Aug 30, 2013
[The bull has spotted the research blind and has taken a warning posture. More square brackets may be necessary. I will attempt to appear nonthreatening.]

Interesting points. I will consider them.

Aug 30, 2013
It's been obvious for a long time that scientist are behind Agenda 21. They plan and scheme to to build the mind control devices called iPads. Everyone knows that. Of course iPads/Pods/Tvs etc are just part of a massive interconnected data sampling system that tell where you are and even what angle the device is positioned. Upright and your carrying it. Flat and your probably un-available (ie it's laying somewhere). With GPS you can monitor a persons actions and intents this way. Just part of the massive Agenda 21 that is underway. Don't you agree?

Global warming certainly does increase the potential for fires via a couple of vectors. 1st; as temperature extremes reach into forested areas and along with it dry conditions, undergrowth can become extremely flammable. 2nd, drought conditions of a long period can also make undergrowth tender and weaken forests. 3rd, temperature increases over a period of years can strengthen insects which can develop faster. All contribute

Aug 30, 2013
As part of the Agenda 21, you have Al Gore, who has been placed in charge of all of the FEMA parks, that will be used as government "re-education" camps, to be taught by scientist. If I was an AGW denier, I would be deeply concerned the about loosing your property to frackers or mountain strips who own most of the teaparty and gop right now. These are the folks that will ship you to FEMA camp 9. Yes sir. As much as they (the masterminds of agenda 21 gop directive) think that you will believe, you will resist, but you know it's futile to resist global warming even a little, so it's off to the camps with you. That's basically what I heard some scientist say.

Wow. I understand you can pick your FEMA trailer in advance? Does anyone know if that is true? Or is that just for certain more upscale regions? Also I understand they judge you on how well you understand two points, AGW and english? If you pass both, you get a better trailer. Is that true?


Aug 31, 2013
Of course. Everything worsens with climate change. Didn't you all know that? We are living at a magic point in climate history. BTW, didn't you also know that the effects of climate change are exacerbated by virtually everything? The compounding and inevitable effects mean only one thing... spontaneous global combustion. But don't take my word for it. Just add up all the articles published here and the mainstream media. It's just a matter of time, and then POOF. We're all ablaze. The speculation is undeniable... or at least as undeniable as our other mass predication, organized religion.

Aug 31, 2013
[[Now that it appears the territory is claimed, and the prey inactive, scavengers begin to move in.]]

Sep 01, 2013
It was my understanding that there was some invasive beetle running around killing off trees, which made forest more prone to large forest fires.

Your understanding is incorrect. Beetle-killed forests are less likely to burn due to lack of "kindling"...google it.

Beetle-killed areas provide a natural fire-break, which will help make forest fires easier to fight. Having fire breaks also means we no longer have to extinguish every fire that starts.

The bark beetle is the only thing that can prevent the total destruction of our forests.

The bark beetle is a gift sent from God and is designed to protect our forests from the ravages of unchecked environmentalism.

Sep 02, 2013
Duh, never would have guessed fires would happen more often in a warmer climate. So is that natures fault or our fault?

Deniers, the fires are our fault for being over populated and permissive, they get worse as the climate warms and as the population grows and they add to global warming. So we are causing that problem that is making the other problem we cause even worse.

Sep 04, 2013
AGW aside, what about everything else we humans are doing? For instance, rain forests being cleared at an unimaginable rate. I once heard people clear an area in comparison to South Carolina in the Amazon. But yet, there is a report of the forest is growing back in Panama. How about the Garbage Gyres? Researchers have commented the disintegrated material looks like snow, only underwater! Why not manage the pollution humanity creates before we try to get politicians involved cramming nonsense down our throats? And if AGW is true, would that help to negate our impact on Earth? Our society's energy needs are petroleum-based, and I see no one commenting about this topic actually trying to do something other than supporting legislative action. That isn't going to solve our issues. Why don't you use your expertise and knowledge to solve our dependence on oil to a system more sustainable?

Sep 07, 2013
F*N morons

I shouldn't have to say this, but it is NOT a story about your social circle.

Thanks, I needed that laugh this morning!

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