Climate Change’s Compounding Effect on California Wildfires

This fire damage map depicts, in red and yellow, areas in northern California that were likely damaged by recent wildfires. Image credit: NASA-JPL/Caltech/ESA/Copernicus/Google.

Wildfires have burned almost nine million acres of land across the West this year, according to the National Interagency Fire Center. Dozens of lives have been lost, thousands of residents have been forced to evacuate from their homes, and the U.S. Forest Service spent $2.41 billion in fiscal year 2017 to put out the fires. The agency had to borrow $576.5 million to cover the costs of fire suppression through the end of the year, and the fires are continuing to burn into fiscal year 2018. Amid a series of other natural disasters and national and international crises, the U.S. government faces a host of serious decisions on how to mitigate future threats as well as recover from recent disasters.

Starting on October 8, a series of wildfires broke out throughout Napa, Lake, Sonoma, Mendocino, Butte, and Solano counties during severe fire weather conditions, leading the U.S. National Weather Service to issue a red flag warning¹ for much of northern California. In the extreme heat and dry conditions, the fires rapidly grew to become massive conflagrations spanning over 200,000 acres and encompassing several cities and towns. The fires destroyed an estimated 6,700 structures, killed at least 42 people, hospitalized over 185, and forced more than 90,000 people to evacuate.

Of the seventeen separate wildfires reported at this time, one of them, the Tubbs fire, grew to become the most destructive wildfire in the history of California. More than 10,000 firefighters battled the blaze, using more than 1,000 fire engines, with crews arriving from as far away as Canada and Australia. By October 13, air quality in the city of Napa reached the "hazardous" level, the most dangerous on the Environmental Protection Agency's scale. In Solano County, over 250 people were sickened by smoke inhalation and sought care at hospitals. Smoke from the fires spread nearly 100 miles, causing unhealthy air quality to be recorded in surrounding regions. For over a week after the fires started, flights continued to be canceled and delayed due to poor visibility from the smoke. In the city of Santa Rosa, 5 percent of the housing stock was destroyed. Because the fire moved through urban areas rather than remaining only in forests, some commentators are referring to this event as an “urban conflagration” rather than a wildfire.

By mid-October, there had already been a greater number of forest fires in the Pacific Northwest this year compared to recent years. Indeed, the 2014 National Climate Assessment predicted that by 2080, wildfires will consume four times as much of the Northwest each year than what burned annually during the 1916 to 2007 period.

There are several reports that at least some of the fires might have been started by power lines and electrical transformers that began shooting sparks, and in some cases, exploded the night that the fires began. Some raised questions about how well Pacific Gas & Electric, the local electric utility provider, had maintained its equipment in the area and whether it had adequately cut back trees from power lines to reduce fire risk – as required by state law. Others, however, rather than focusing on negligence on anyone’s part, are instead attributing this catastrophe to the changed climate that human civilization has created – hotter and with bigger variations and fluctuations. Regardless of what produced the initial sparks, the overwhelming evidence leads to the conclusion that human-induced climate change made the fires spread more quickly.

 

A Scientific Consensus

The overwhelming majority of scientific evidence concludes that climate change magnifies the effects of wildfires in California and elsewhere, and that those effects are poised to increase in the coming decades. Noah Diffenbaugh, Professor of Earth System Science at Stanford University, studies the links between single extreme events and climate change. In his research papers, he notes the ‘perfect storm’ of conditions that set the stage for 2017’s catastrophic wildfires. California’s recent five-year drought killed more than 100 million trees, building up huge amounts of fuel over the area. Also, the 2016-17 winter was extremely wet, producing an excess of vegetation, which was followed by a hot, dry summer season (California’s hottest summer on record), which dried that vegetation, leading to ideal conditions for forest fires.

Another authority on wildfires, Michael Flanagan, Director of the Western Partnership for Wildland Fire Science at the University of Alberta, Canada, published a study in 2016 in the Proceedings of the National Academy of Sciences suggesting that climate change has already played a significant role in making forests in the western United States drier and more likely to burn, nearly doubling the area affected by forest fires over the last three decades. In some places, including California, scientists have predicted that climate change will cause more intense droughts as well as more extreme precipitation. The increase in rainfall, followed by hot, dry, windy weather can lead to sudden, intense fires.

Climate scientists agree that climate change is causing several phenomena that contribute to an increase in wildfires. Fires are started by either humans or lightning, and both of these risk factors are increasing. With more people living at or near the interface between forests and cities, human activity that can induce fires (whether accidental or intentional) is inevitably on the rise. Human influence is also felt in the types of vegetation we plant and how we manage our plants—in many cases, our decisions can increase the intensity and likelihood of fires.

As for natural risk factors, a 2014 study published in the journal Science predicted that the number of lightning strikes could increase by 12 percent for every degree Celsius of warming. A study published in 2017 in Nature Climate Change concluded that lightning ignitions in North America’s northern boreal forests have increased since 1975, and that future warming may cause more storms, more lightning, and more fires. Multiple recent scientific studies indicate that spring is arriving earlier in many places, which means that snow is melting sooner, increasing the potential for drought later in the year, and thus, wildfires. In addition, multiple studies have found that winds in California and other western areas are increasing in strength, likely driven by climate change. An increase in winds can exacerbate wildfires, by helping them to spread.

In discussing the increase in wildfires, Edward Struzik, a fellow at the Institute for Energy and Environmental Policy at Queen’s University in Kingston, Canada, recently stated that “…there’s been a consistent pattern evolving since the 1980s and 1990s… Many wildlife experts saw this coming a long time ago, [but] the politicians and the public never really signed on.”

 

A Global Phenomenon

Several other wildfires around the world this year provide further evidence that the increasing risk of fire is consistent and universal. This past summer, fires in British Columbia, Oregon, and Washington state produced smoke that spread to Montana, Idaho and Alberta, prompting health-related warnings for people with respiratory problems.

In Europe, more than 600 wildfires were reported in Portugal and Spain in October alone, killing 49 people and injuring dozens more. Heavy winds, due in part to Hurricane Ophelia's passing through the region, exacerbated the fires, and the dry vegetation caused by a hot summer provided plentiful fuel. Portugal had also just experienced another set of devastating wildfires in June of this year.

Other areas around the Mediterranean region were unusually dry this summer, and numerous major wildfires were reported in southern France, Italy, Croatia, Montenegro, and Greece. Officials in all of these countries have speculated that these unprecedented fires were exacerbated by climate change. There is consensus among European scientists that summer heat waves will become more intense in the future.

 

Federal Firefighting Funding Issues

As a result of the increased fire activity, the U.S. Forest Service has been spending a greater and greater proportion of its budget on fighting wildfires, such that more than half of its budget is now spent on wildfires. Spending on wildfire suppression is projected to increase to two-thirds of the Service's budget within a decade. That leaves less and less funding for fire prevention programs.

In June, bipartisan legislation titled the Wildfire Disaster Funding Act (HR 2862) was introduced in the House to address the U.S. Forest Service fire funding issue. The proposal is similar to what was proposed in President Obama’s 2016 budget. Similar legislation was introduced in the Senate (S. 1842) in September. The legislation would end the practice of “fire transfers” (where the Forest Service has to take funding away from its other programs to pay for firefighting), and allow agencies to use disaster funds to put out fires, as is the practice for other natural disasters. It would also dedicate more resources to forest thinning, restoration and improvement activities. The U.S. Forest Service would still pay for 70 percent of fire management costs, but for the small number of fires that account for the additional 30 percent of costs, the Forest Service could access disaster funding. The bill would also raise the budget cap for disaster funding so that wildfires wouldn’t syphon money away from recovery efforts or require wildfires to compete with other natural disasters for funding. The House bill currently has 79 bipartisan cosponsors, and the Senate bill currently has 10 bipartisan cosponsors, but no hearings on the bills have been scheduled in their respective budget committees.

On October 25, the USDA announced that it was making additional resources available (through its Community Facilities Program and its Water and Waste Disposal Loan and Grant Program) to help rural people and communities recover from the effects of California's wildfires. It is not clear whether these actions will be adequate in addressing the hardships these communities are facing.

 

Preventing and Mitigating Future Fires

Fire devastation in and around Santa Rosa, California. Photo credit: California National Guard.

Advocates of wildfire preparedness argue that when building in fire-prone areas, developers should be required to use fire-resistant materials and should build farther away from vegetation. They should also plan for more strategic vegetation management (i.e., clearing shrubs and brush away from neighborhoods on a regular basis). One such advocate argues that developers cannot keep building “sprawl into our fire-dependent ecosystems and expect firefighters [to] risk their lives to defend each new McMansion,” and further argues that better forest management would focus more on reducing “the greenhouse gas emissions that caused this crisis.” That being said, the carbon dioxide and other greenhouse gases released by fires further exacerbates climate change, making fire prevention an important tool in mitigation efforts. Others add that our society needs to change its patterns of living toward more urban concentration, mass transit, zero-energy buildings, and clean energy, and that we also need to learn how to better warn people of an oncoming fire and how to evacuate them more quickly.

 

Author: Richard Nunno

 

¹ A red flag warning is a call for firefighting agencies to alter their staffing and equipment resources to accommodate a forecasted risk, and an alert to the public of an extreme fire danger that is likely to quickly spread to vegetation in the area.