Over the past few days, a 1.5 million acre (2,350 square mile) swath of the Central U.S. has burned. The wildfires, stoked by warm winds, prodigious undergrowth, and a nascent mid-western drought exploded across Texas, Oklahoma and Kansas. Six people have perished, numerous structures have been destroyed, and thousands of people have been forced to evacuate. According to initial reports, the losses in the form of cropland burned and livestock consumed by the flames are expected to be significant.
(Large wildfires and massive burn scars are clearly visible in this March 7 NASA satellite shot of North Texas, the Oklahoma Pan-Handle and Southern Kansas. For reference, bottom edge of frame is approximately 120 miles. Image source: LANCE MODIS.)
For Kansas, a single blaze covering 1,000 square miles was likely the largest fire ever to strike the state. Meanwhile, similar enormous fires ripped through nearby Oklahoma and North Texas (see satellite image above). Though more favorable weather conditions for firefighting are on the way, concerns remain that the fires could continue to grow throughout the weekend.
It is not an unheard of event for wildfires to strike the plains states during winter. However, the rising frequency and intensity of large fires during recent years has been a cause for growing concern among climate researchers. And though humans and lightning strikes often provide the ignition sources for the wildfires that do occur, it is the underlying heat and drought conditions which can cause a wildfire to explode into an out of control monstrosity when such an ignition inevitably occurs. To this point, it’s worth noting that a similar large wildfire outbreak occurred during the winter of 2010-2011 — a time when near record warmth combined with drought to scorch 4,000 square miles in Texas and Arizona. And we should also note that global warming will tend to bring on these wildfire favorable conditions with increasing frequency and intensity.
(Near record warmth and below average precipitation over the past month set the stage for extreme wildfire risks this week. Increasingly, such anomalously warm temperatures and rapid onset drought conditions are driven by human-caused climate change. Image source: NOAA.)
This year, similar climate change related conditions set the stage for this past week’s dangerous outbreak. And though some researchers consider the fire regime in this region of the U.S. during this time of year to be cyclical in nature (possibly driven at least in part by the ENSO cycle), the added heat and increasing risk of intensifying drought periods due to climate change plays a role in the worsening fire regime as well.
According to the Union of Concerned Scientists, wildfire season in the Western U.S. has already grown from 5 months per year to 7+ months per year due to rising temperatures. This added heat and related expansion of the wildfire season has helped to increase the average number of large fires burning during any given year in this region from approximately 140 per year during the 1980s to 250 per year from the period of 2000 to 2012.
(Union of Concerned Scientists graphic shows stark wildfire trend for the Western U.S. A trend that is being repeated in many regions across the country due to climate change’s rising temperatures and increasingly intense precipitation extremes. See full infographic here: Union of Concerned Scientists.)
For the Central U.S. the story is much the same as researchers have warned that the frequency and intensity of wildfires likely would continue to increase in the coming years, given the confluence of climate change related factors such as higher temperatures and lower rainfall amounts. In Phys.org today, University of Illinois atmospheric sciences professor Don Wuebbles noted that increasingly intense wildfires are:
“…Probably… the new normal. Thirty years from now, we may look upon this as being a much better period than what we may be facing then.”
Hat tip to Colorado Bob