“To live better with fire, we need to adapt to fire” is a thought paradigm many fire community leaders and people have or are adopting to address their wildland-urban interface issues. The 2017 wildfire season again demonstrated the urgency in which communities need to adapt to fire in order to live better in the communities we call home. This article describes what may be called the modern wildfire situation and some of the forces driving wildfire conditions today.
The western wildfire season of 2017 burned millions of acres across California, Oregon, Washington, Idaho, Montana and British Columbia, with smoke stretching across the Great Plains. More than 6,000 homes were destroyed and 42 people died in California. Meteorologists explained: “After above-average winter rain and snowfall, the western U.S. has been relatively dry this summer, but extremely hot. A large ridge of high pressure has been parked over the West for months, causing the area to bake.”1 Arizona had its share of wildfires earlier this summer too, including the Goodwin, Burro and Frye Fires, all of which were more than 27,000 acres in size.
While there are many factors involved, the conditions for today’s wildfire situation can be largely attributed to three:
1) 20th century fire suppression policies;
2) The increase of human settlements in the wildland-urban interface; and
3) The global warming trend since the latter part of the 20th century.
Nearly all forests and woodlands in the western states evolved with wildfire as a crucial part of their ecology. Twentieth-century forest management, however, centered on a fire suppression policy (in response to uncontrollable wildfire events during the late 19th and early 20th centuries). This policy was quite successful until the great Yellowstone Fire in 1988, when 793,880 acres of the national park were consumed by uncontrollable wildfire.
In addition to the unnatural buildup of forest fuel (an unintended consequence of fire exclusion), many more people were living in the wildland-urban interface of western forests and woodlands by the end of the 20th century. The realization that these communities were threatened by uncontrollable wildfire became evident as well, particularly with the 1990s wildfires in Southern California when thousands of homes were destroyed by wildfire. This includes the 1990 Painted Cave Fire; 1991 Tunnel/Oakland Fire; and 1993 Laguna Hills and Old Topanga Fires2. Arizona’s own wildfires, 2002 Rodeo-Chediski Fire and the 2003 Aspen Fire on Mt. Lemmon, destroyed 426 and 340 homes, respectively.
At the same time, temperatures in the latter part of the 20th century are increasing. It is a direct relationship that warmer temperatures increase evaporation, creating drier forest conditions in the arid West.
To estimate wildfire behavior, firefighters use the Wildfire Behavior Triangle, which considers the relationships between fuels, weather and topography. Thus, modern conditions are right for large amounts of dry fuel to burn due to historical fire suppression and warmer temperatures, and those homes and communities in the wildland-urban interface are particularly at risk.
Dr. Paul Hessburg, research ecologist with Pacific Northwest Research Station, U.S. Forest Service has deemed we live in the Era of Megafires3, defined as wildfires over 100,000 acres in size. Between 1997 and 2016, the National Interagency Fire Center lists 177 U.S. wildland megafires, ranging from 100,000 to 1,305,592 acres4.
Both fuels and weather are essential components of fire behavior. As such, it would be wrong to fault the modern wildfire situation on global warming alone, just as it would be wrong to discount global warming. Climate change is the acceleration of the earth’s hydrologic process caused by global warming.
Let’s break that down: Acceleration is the ongoing upward trend of extreme weather phenomena, both in frequency and intensity. These include droughts, heat waves, record-breaking temperatures, milder winters, dust storms, micro-bursts, floods, hurricanes and tornadoes. These are all mechanisms of earth’s water cycle for the transfer of moisture. The increase in these events is documented and observable.
Just as the earth has a water cycle, it has a carbon cycle. Energy made from carbon-based, mined material such as coal, oil and natural gas, produces atmospheric carbon dioxide (CO2) as a byproduct. “Since 1751, approximately 374 billion metric tons of carbon have been released to the atmosphere from the consumption of fossil fuels and cement production. Half of these fossil-fuel CO2 emissions have occurred since the mid-1980s.”5
In 1958, CO2 concentration was measured at 315 parts per million at the Mauna Loa Observatory and was increasing at a rate of around 0.7ppm per year. Today, it is more than 405ppm and increasing at 3ppm per year6. That is an increase of more than 25 percent in 60 years. Unfortunately, this upward trend has no end in sight.
To tie this back to the modern wildfire situation, western wildfires have gotten to such an environmental point that the technological advances of the 20th century that made wildfire suppression so successful for so long have been overwhelmed. A change in the thought paradigm of wildfire has become necessary: “To live better with fire, we need to adapt to fire.” Indeed, much has been accomplished in Rim Country to address the wildfire situation in the past 15 years.
As more community members come to this realization, our communities can continue to address wildland-urban interface issues effectively, to the point where forest fires can happen without threat to adjacent communities, and both the forest and communities are resilient now and into the future.
Christopher Jones is a University of Arizona extension professor who is teaching a class on the climate change debate at Gila Community College.