Hot-Burning Forest Fires Can Cool Climate: UCI
A UC Irvine study of fires concludes that blazes that burn the hottest actually cool the climate. And you wonder why high school science made my head hurt.
Actually, the research funded by NASA and the National Science Foundation was aimed at determining how differences in individual tree species between Eurasia and North America alter the continental patterns of fire.
"High-intensity canopy fires are prevalent in boreal North America, whereas lower-intensity surface fires are common in Eurasia," explains Brendan Rogers, a UCI doctoral student now at Woods Hole Research Center in Massachusetts. "These differences have large-scale implications for fire ecology, climate modeling and forest management. Yet their patterns, consequences and underlying causes were not well understood."
Rogers and UCI Earth System Science professors James Randerson and Michael Goulden used remote sensing imagery to discover that conifer trees are the drivers--rather than the passive victims--of the types of fire that consume them. Amber Soja of the National Institute of Aerospace and NASA's Langley Research Center also contributed to the research.
In North America, tree species known as "fire embracers" have evolved to both spread and be destroyed by fire. Mature stands of black spruce, which are ubiquitous in Canada and Alaska, burn like a torch and cause intense treetop fires that kill the canopy. But in Eurasia, thick bark and sparse lower branches of "fire resisters" allow them to largely survive flames, which creep along the forest floor consuming underbrush.
Understanding the effects during and after fires of different tree species is important in developing accurate Earth system models used by scientists studying climate change, according to the researchers.
"Current global fire models neglect the influence of these species-level traits, thereby misrepresenting boreal fire dynamics and their associated feedbacks to climate warming," Rogers says. "We need to move beyond the use of generic representations of trees and use the information from our study to make informed decisions on how to manage these forest fires for climate mitigation."