Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

More Large Forest Fires Linked To Climate Change

07.07.2006
Large forest fires have occurred more frequently in the western United States since the mid-1980s as spring temperatures increased, mountain snows melted earlier and summers got hotter, according to new research.

Almost seven times more forested federal land burned during the 1987-2003 period than during the prior 17 years. In addition, large fires occurred about four times more often during the latter period.

The research is the most systematic analysis to date of recent changes in forest fire activity in the western United States. The increases in fire extent and frequency are strongly linked to higher March-through-August temperatures and are most pronounced for mid-elevation forests in the northern Rocky Mountains.

The new finding points to climate change, not fire suppression policies and forest fuel accumulation, as the primary driver of recent increases in large forest fires.

"I see this as one of the first big indicators of climate change impacts in the continental United States," said research team member Thomas W. Swetnam, director of the Laboratory of Tree-Ring Research at The University of Arizona in Tucson.

"We're showing warming and earlier springs tying in with large forest fire frequencies. Lots of people think climate change and the ecological responses are 50 to 100 years away. But it's not 50 to 100 years away -- it's happening now in forest ecosystems through fire."

The researchers found the wildfire season now starts earlier, fires last longer and the fire season ends later.

"The length of the fire season has increased almost two-and-one-half months compared with 1970 to 1986," Swetnam said. "That's a remarkable thing in itself."

In recent years, wildfires in the western United States have burned hundreds of homes annually and caused extreme and sometimes irreversible damage to natural resources. Fire-fighting expenditures for wildfires now regularly exceed one billion dollars per year.

The research report will be published in the July 6 issue of Science Express, the online version of the journal Science. Anthony L. Westerling, then of Scripps Institution of Oceanography in La Jolla, Calif., led the research team, which included Scripps scientists Hugo G. Hidalgo and Daniel R. Cayan and UA's Swetnam. Westerling is now at the University of California, Merced. The National Oceanic and Atmospheric Administration, the U.S. Forest Service and the California Energy Commission funded the research.

The fire management and scientific communities have thought that U.S. forest fires have been increasing since the 1980s. Research to explain such fires has focused on either climate or 19th-and-20th century land-use practices, such as livestock grazing, logging and fire suppression.

To see what role climate might play, the Scripps-led research team compared western U.S. fire history, the timing of snowmelt, and spring and summer temperatures for the 34 years from 1970 to 2003.

From wildfire data covering western U.S. Forest Service and National Park Service lands, the researchers compiled a comprehensive time series of 1,166 forest wildfires of at least 1,000 acres that had occurred between 1970 and 2003.

To figure out the timing of peak snowmelt in the mountains for each year, the researchers used the streamflow gauge records from 240 stations throughout western North America.

The team also used other climatic data including seasonal temperature observations and moisture deficit, an indicator of dryness.

The researchers determined that year-to-year changes in wildfire frequency appear to be strongly linked to annual spring and summer temperatures and to the timing of spring snowmelt.

"At higher elevations what really drives the fire season is the temperature. When you have a warm spring and early summer, you get rapid snowmelt," Westerling said. "With the snowmelt coming out a month earlier, areas get drier overall. There is a longer season in which a fire can be started and more opportunity for ignition."

The researchers found that 56 percent of the wildfires and 72 percent of the total area burned occurred in early snowmelt years. By contrast, years when snowmelt happened much later than average had only 11 percent of the wildfires and 4 percent of the total area burned.

Climate model projections suggest warmer springs and summers are more likely to occur in the West, amplifying the region's vulnerability to wildfires, the researchers note in their article.

The researchers suggest that more severe fires could change forest composition so drastically that the western forests, which currently store atmospheric carbon dioxide, could become a source of atmospheric CO2. Additional carbon dioxide could further warm the climate and exacerbate the fire problem.

Swetnam was initially skeptical that climate was driving recent large-scale changes in fire frequency. Doing this research changed his mind.

"I had thought it was primarily fuel load. These results suggest that for most western U.S. forests, climate is a primary driver and fuel is secondary." He added, "In the Southwest we know we have a fuel problem. You lay on top of that warming temperatures and now we have the worst of both situations -- changed forests and changed climate."

Mari N. Jensen | University of Arizona
Further information:
http://www.arizona.edu
http://www.ltrr.arizona.edu
http://www.scripps.ucsd.edu/

More articles from Ecology, The Environment and Conservation:

nachricht Upcycling 'fast fashion' to reduce waste and pollution
03.04.2017 | American Chemical Society

nachricht Litter is present throughout the world’s oceans: 1,220 species affected
27.03.2017 | Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung

All articles from Ecology, The Environment and Conservation >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Making lightweight construction suitable for series production

More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.

Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...

Im Focus: Wonder material? Novel nanotube structure strengthens thin films for flexible electronics

Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.

"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...

Im Focus: Deep inside Galaxy M87

The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.

Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...

Im Focus: A Quantum Low Pass for Photons

Physicists in Garching observe novel quantum effect that limits the number of emitted photons.

The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...

Im Focus: Microprocessors based on a layer of just three atoms

Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.

Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Fighting drug resistant tuberculosis – InfectoGnostics meets MYCO-NET² partners in Peru

28.04.2017 | Event News

Expert meeting “Health Business Connect” will connect international medical technology companies

20.04.2017 | Event News

Wenn der Computer das Gehirn austrickst

18.04.2017 | Event News

 
Latest News

Wireless power can drive tiny electronic devices in the GI tract

28.04.2017 | Medical Engineering

Ice cave in Transylvania yields window into region's past

28.04.2017 | Earth Sciences

Nose2Brain – Better Therapy for Multiple Sclerosis

28.04.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>