Fire As a Factor in Climate Change

UCSB Study Calls for Inclusion of Wildfires in Assessment of Atmospheric Shifts

Fires can be devastating – they have the ability to scorch terrain, destroy housing, and wreak havoc upon any specific human community or natural ecosystem. However, according to a recent article in the April 24 issue of the academic journal Science, fires should not only be studied as singular and isolated natural disasters, but also as cumulative phenomena that contribute significantly to global climate change.

Through their presented research, the article’s authors (which include a number of UCSB faculty members as the project was headed by the UCSB-based Kavli Institute for Theoretical Physics and the National Center for Ecological Analysis and Synthesis) call on the Intergovernmental Panel on Climate Change to fully integrate fire into its reports on global atmosphere change, taking into careful consideration fire-climate feedback models.

Such models, which have thus far been largely absent in global climate studies, attempt to discern the amount of carbon dioxide that is emitted by burning plants during large-scale blazes. By first determining the amount and concentration of carbon in area-specific vegetation, researchers are able to calculate just how much carbon dioxide – the most studied and well-known contributor to global climate change – is released into the air when said vegetation is burned. This process, known as photosynthesis combustion, is interestingly the exact opposite chemical process of regular photosynthesis.

While the article’s authors admit that their estimate of fire’s influence on climate is simply a jumping-off-point for further discussion and study, they nevertheless address the major research gaps that must be filled if we are to fully understand and appreciate all of the elements that help shift Earth’s atmospheric balance. Speaking about the necessity for a more holistic approach to fire science, UCSB post-doctoral candidate and co-lead author of the study, Jennifer Balch, stated, “We don’t think about fires correctly. Fire is as elemental as air or water. We live on a fire planet. We are a fire species. Yet, the study of fire has been very fragmented. We know lots about the carbon cycle, the nitrogen cycle, but we know very little about the fire cycle, or how fire cycles through the biosphere.”

Author Carla D’Antonio, Bren School professor and longtime researcher of Southern California’s chaparral ecosystems, explained how Santa Barbara’s three recent Zaca, Gap and Tea fires factored into the Science article. She stated that although the Gap and Tea fires were “small potatoes” with regard to sheer size and affected acreage, the Zaca fire was on the scale of blazes that will be factored into future fire-climate feedback models. In terms of magnitude, said D’Antonio, the Zaca wildfire was not unlike the recent Amazon basin blazes that have scorched thousands of acres of rainforest.

However, while the incidence of fires is noticeably increasing within the Amazon due to expanding agriculture and cattle ranching, Santa Barbara’s fires are “not out of the ordinary. We live in a fire-prone ecosystem,” D’Antonio said, “and right now it’s hard to say if what we’ve seen in the last 20-30 years is abnormal. For instance, I don’t think you can look at Santa Barbara and say there’s been less rainfall.” And Santa Barbara’s climate, D’Antonio asserted, with its many abnormal factors including coastal fog as well as Santa Ana and Sundowner Winds, make studying the area’s fires even more complicated. “It’s always a relative issue. We have a very variable climate here and we don’t know yet if we are a signal of climate change,” D’Antonio said of the possible effects that Southern California’s human infrastructure has on fire incidence and severity.

When asked what she thought the article’s central issue or argument was, D’Antonio stated, “Right now in the climate change world, fire is not included in models – you never hear about fires. We want to put fire on the radar screen and increase visibility as to the role fires will play in any forthcoming climate change.”