Scientists highlight fire's impact on climate - April 24, 2009
There's no doubt that forest fires release enormous amounts of carbon dioxide and soot into the atmosphere. There's also no doubt that fire is every bit as natural as rain and snow, which in theory means that forest regeneration would balance things out over time. The question facing researchers is to what extent global warming might fuel this natural trend with droughts and heat waves.
A group of scientists penned a review article in this week's edition of Science calling for a more aggressive research agenda on these questions. Exhibit number one: Although the Intergovernmental Panel on Climate Change highlighted the issue and suggested that the fire cycle could become more active in a warmer climate, no attempt was made to quantify this effect. The article has gotten considerable press (see here and here), mostly focusing on the top-line assessment that fires will beget more fires.
Not surprisingly, the researchers suggest that by far the biggest impact of fire in terms of carbon dioxide emissions is from the slash-and-burn techniques for clearing forest. From this perspective, fire is a surrogate for deforestation, and they estimate this effect at 19 percent of human greenhouse gas emissions.
That is broadly in line with the notion that deforestation is responsible for a fifth of emissions, but as Thomas W. Swetnam, a University of Arizona researcher and one of the authors, suggests in this story on mongabay.com, that number is more likely to go up than down as the science comes in.
The National Science Foundation has a quick post here, linking to a teleconference with three of the scientists.
