How will climate change impact future fire activity?
Fires aren’t an easy thing to predict. However, with fire activity growing across portions of the planet – both the United States and Russia are experiencing an exceptionally severe 2012 wildfire season – scientists are trying to understand what role climate change could have on fire activity in the future. Now, a new scientific study predicts that as much as 62% of the northern hemisphere could see an increase in fire activity by the end of the 21st century. The study was published on June 12, 2012 in the journal Ecosphere.
To predict future fire activity, scientists first built a statistical model using historical fire occurrence data from 1971 to 2000. In their model, they related the historical fire data to climate variables including temperature and precipitation. In some cases, they included information on net primary productivity as surrogate measure for biomass availability. Biomass availability can be an important factor for predicting fires. For example, deserts have low fire activity because they have little to no biomass available to burn, whereas forests have higher fire activity because they contain large amounts of flammable biomass.
Next, they used the model to forecast future fire activity for the time periods of 2010 to 2039 and for 2070 to 2099. The forecasted fire data were based upon changes in temperature and precipitation predicted from 16 different global climate models under a mid-to-high emissions scenario. The mid-to-high emissions scenario predicts that global surface temperatures will increase from 2000 levels by about 3.5 degrees Celsius (6.3 degrees Fahrenheit) in 2100.
Fire data from Antarctica and small islands were not included in their analyses.
The model predicted that 38% of the planet would likely see an increase in the frequency of fires over the next few decades. By the end of the 21st century, the model predicted that as much as 62% of the planet could see an increase in fire activity. Predicted increases in fire activity were largely located in the northern hemisphere.
In the southern hemisphere, the model predicted that fire activity would likely decrease across portions of the tropics and sub-tropics throughout the 21st century. These decreases could impact about 8% of the planet over the next few decades and about 20% of the planet by the end of the 21st century.
The authors note that their study is in agreement with some key studies, but not all of the small number of past studies that have attempted to forecast future fire activity across the globe. Again, fires aren’t an easy thing to predict but it’s important that science attempt to do so. The study was published in an open-access journal and can be accessed here. Figure 6 is worth a look for those who are interested in viewing where fire activity may increase or decrease over the 21st century.
Max Moritz, lead author of the study published in Ecosphere, is an extension specialist in fire ecology and management at the University of California, Berkeley. Co-authors of the study included Marc-André Parisien, Enric Batllori, Meg Krawchuk, Jeff Van Dorn, David Ganz and Katherine Hayhoe.
On another important note, preliminary data (pdf) from the National Interagency Fire Center (NIFC) released on September 27, 2012 indicate that the amount of land burned by wildfires in the United States during 2012 has now surpassed the amount of land burned in 2011. In 2011, a total of 8,711,367 acres (35,254 square kilometers) of land was burned by wildfires. The year 2011 was ranked as the third-most-active wildfire season in the United States since record-keeping began in 1960. Now, it appears that 2012 will be at least the third worst wildfire season on record. As of September 27, 2012, a total of 8,720,743 acres of land (35,292 square kilometers) have already burned, and the wildfire season isn’t over yet.
Wildfire activity in the United States during 2012 has been exacerbated by the high temperatures and severe drought that gripped much of the nation.
Russia is also experiencing an exceptionally severe 2012 wildfire season. You can read more about the 2012 wildfires in Russia in a September 17, 2012 EarthSky blog post.
New models that can help to forecast future fire activity are sorely needed, and they will likely be a valuable tool for natural resource managers who are trying to identify vulnerable areas and minimize the damage from wildfires.
Bottom line: A new scientific study predicts that as much as 62% of the northern hemisphere could see an increase in fire activity by the end of the 21st century. In the southern hemisphere, fire activity is expected to decrease across portions of the tropics and sub-tropics by the end of the 21st century. The study was published on June 12, 2012 in the journal Ecosphere.