Global Warming-Enhanced Wildfires
Iris Stewart-Frey and Ed Maurer
(AP Photo/Nick Ut)
Iris Stewart-Frey is an associate professor of environmental studies and sciences, and Ed Maurer is a professor of civil, environmental, and sustainable engineering, both at Santa Clara University. The views expressed in this piece are those of the authors.
The Camp Fire, the deadliest fire in California’s recorded history, is officially contained as of today. The fire rose suddenly and gripped Northern California in the days leading up to Thanksgiving, and it virtually wiped out the town of Paradise in the Sierra Nevada foothills north of Sacramento. Its deadly swipe has left thousands of people homeless and dozens dead, with several hundred still unaccounted for. Lives in this town of formerly 26,000 have been permanently upended, with loved ones lost and the close-knit community fabric ripped.
Yet much of the copious reporting and political commentary on the fires avoid what has become a political hotbed – the connections of natural disasters like fires, floods, droughts, and hurricanes to climate change, and the human suffering and economic strain that they already impose here and now in the United States (as well as in places around the world that have done much less to contribute to global warming and are in a much weaker position to prepare for its impacts). Developing strategies for climate adaptation and mitigation requires our full commitment as a human society, our collective actions, our most ingenious innovations, and our financial resources. Continual denial of the human causes, effects, and likely impacts of climate change for short-term economic gain and political expediency weakens those commitments and silently accepts that we leave those that are least able to adapt in harm’s way.
One of the most recent examples of this type of climate denial came in the form of a presidential tweet on November 10, which read:
There is no reason for these massive, deadly and costly forest fires in California except that forest management is so poor. Billions of dollars are given each year, with so many lives lost, all because of gross mismanagement of the forests. Remedy now, or no more Fed payments!
Ironically, the latest volume of the congressionally-mandated National Climate Assessment features wildfire on its cover and includes in-depth summaries of infrastructure, health, and economic impacts of fires enhanced by global warming. This report has been long in the making, but was released just days after the president’s Twitter statement, on Black Friday, when many of us are less focused on news. By contrast, California has shown considerable leadership in promoting and funding science-driven forest management, advocating forest restoration, prescribed burns, and thinning of overgrowth. However, the state only controls about 3 percent of forested land, with the lion’s share being under federal control. That is why federal leadership on this issue is so crucial.
Paradise was a place of fixed incomes. According to the latest census figures, 25 percent of the residents in Paradise were retired—almost twice the state average—and 18 percent were living with disabilities, compared with about 6 percent statewide. At the same time, the median income in Paradise was only about 75 percent of the state average. As a result, many of the people affected by the fires are among the most vulnerable: The elderly, the disabled, those who cannot afford to “move and start over”. Could at least some of the deaths and destruction have been avoided if, instead of sidestepping responsibility and sowing mistrust, we educated people on the state of scientific research about the connections between fire, forest management, and climate, and started to put resources towards mitigation measures?
The 2018 California wildfire season has been the most destructive on record, with a total of 7,579 fires burning an area of 1,667,000 acres, the largest area in any given year. These fires have caused $3 billion in damages. California is burning, but it is hardly alone. Up and down the western half of the country, wildfires were raging in states as diverse as Alaska, Idaho, and Arizona. During the heat of the 2018 summer, 92 fires were burning at the same time.
In the West, natural forest systems periodically burn with low-intensity fires that clear brush, help germination, and result in more fire-, pest- and disease-resistant, open forests. However, for over a century forest management has intercepted these processes and mainly centered on fire suppression. The goals were laudable: Agencies kept the general public safe and protected lands and natural resources such as timber and oil. Yet we may have done more harm than good. Although fire suppression may satisfy short-term goals, in the long run, it encourages the growth of denser forests with less fire-resistant species and more fuel, greatly exacerbating the size and intensity of wildfires.
Along with an intense fire season, 2018 is shaping up to be the fourth warmest year on record, only exceeded by the three previous years. In California, these warm years have been overlapping with the most intense drought in recorded history. Throughout the West, drought and heat have weakened trees and made them susceptible to disease and pests such as the pine beetle that devastates forests as far north as Canada. Dead and weakened trees and excessive wood fuel from fire suppression have turned California into one giant tinderbox.
So can we blame those raging fires on human-induced climate change? The scientific evidence suggests that while we cannot pin a particular fire on climate change, their bundled appearance is consistent with the processes scientists understand and can describe, measure, and calculate.
Based on physical processes, elevated greenhouse gas concentrations make warmer temperatures, shifts in precipitation, and climatic extremes much more likely. In California, declining rains in September, October, and November have extended the fire season at a time when vegetation and soils are at their driest. If rain had come by early November of this year, Paradise might still be standing. Although there is still much to learn about the way fires burn, warmer temperatures, precipitation shifts, and intense droughts facilitate extreme fire seasons and are consistent with what scientists expect from global warming. And while part of our current fire crisis most certainly has its roots in forest management practices and human settlement patterns, we now have an opportunity to plan for a fire future for people and forests without putting on blinkers when it comes to climate.
Healthy forests and forested grasslands are vibrant ecosystems that provide us with water, timber, biodiversity, recreational opportunities, and living spaces. They are part of why so many people find California and the West attractive places. On our current trajectory, we continue to suppress low-intensity fires in increasingly warmer environments, and are setting ourselves up for more frequent and intense mega-fires, while allowing the settlement of high-risk areas by people.
Alternatively, we can rethink our path forward to help our forests and grasslands establish a new equilibrium between tree growth, fuel generation, low-intensity fire, and warmer temperatures. Most likely that would mean some controlled burns and greater control of where and how people live in regions of high fire risk. It would mean educating people on climate change risks and preventive strategies as well as providing affordable housing in lower-risk areas. It also means that we need to fund research and projects in areas as diverse as fire behavior, disaster preparedness, economic recovery, and forest restoration. We also need to accept a transition period to this new strategy and its outcomes. In the longer term, such an approach will save lives in the many towns like Paradise in the U.S. and abroad, and help us develop adaptation strategies to protect our economic and natural assets in a changing world.