Summit County Citizens Voice

Feedback loop could intensify impacts to carbon cycle

Massive fires have burned across more than 3 million acres in Texas. PHOTO COURTESY TEXAS FOREST SERVICE. Click on the image for a gallery of photos from this year's wildfires.

By Summit Voice

SUMMIT COUNTY — Scientists speaking at an international symposium in Australia this week said wildfires are likely play an increasingly important role in climate change, but that more study is needed to determine exactly what those effects will be.

Fires are one of nature’s primary carbon-cycling mechanisms, said Dr. Melita Keywood, a researcher with Australia’s national research agency, the Commonwealth Scientific and Industrial Research Organisation.

A press release from CSIRO highlighted some of the questions Keywood raised in a recent presentation at a gathering of geophysicists.

“Understanding changes in the occurrence and magnitude of fires will be an important challenge for which there needs to be a clear focus on the tools and methodologies available to scientists to predict fire occurrence in a changing climate,” Keywood said.

She said the link between long-term climate change and short-term variability in fire activity is complex, with multiple and potentially unknown feedbacks.

“Fires require fuel to burn and climate strongly affects the type, quantity and quality of fuel. Periods of high rainfall or high atmospheric carbon dioxide levels may result in increased biomass growth so that fuel loads may be enhanced in future fire seasons.

“Reduced water availability associated with drought may also result in drier biomass that is more readily burned in possibly more intense fires, while higher temperatures and other extreme weather may lengthen fire seasons and result in increased likelihood of fire ignitions and longer burning periods. Vegetation types are also altered in a changing climate.

“In turn, fires influence climate by the emissions to the atmosphere of aerosols and GHG, and by affecting the ability of terrestrial ecosystems to sequester carbon.”

Dr Keywood said there is some evidence that fire activity may already be increasing in western U.S. forests and recent exceptionally intense fire events — such as the Australian Black Saturday fires in 2009 and Russian fires in 2010 – highlight the devastation resulting from fires associated with extreme weather.

“Wildfires and biomass burning are important for a range of international and domestic policies – from air pollution to climate, poverty, security, food supply, and biodiversity.  The impacts of emissions from fires on global atmospheric chemistry, and on the atmospheric burden of greenhouse gases and aerosols, are recognized, but gaps remain in our scientific understanding of the processes involved and the environmental consequences of fires.

“These feedbacks between fire and climate change reinforce  the need for fire-related research  that is based on scientifically sound measurements and modelling” she said.

“While significant uncertainty remains in the long-term impacts of forest fires on climate, new sophisticated observational and modeling tools have recently become available. These tools provide insight into changing wildfires and intentional biomass burning emissions on the current and future climate.

“These feedbacks between fire and climate change reinforce  the need for fire-related research  that is based on scientifically sound measurements and modelling” she said.

Filed under: climate and weather, Environment, forest fires, Forest health, forests, global warming, world news Tagged: | Australia, Black Saturday bushfires, carbon cycle, climate change, Commonwealth Scientific and Industrial Research Organisation, global warming, Summit County News, wildfire, Wildfires