Why U.S. Wildfires Will Only Get Worse
Fires in California and Oregon have been more devastating than ever before, but climate change means the worst is yet to come. Here’s how officials can prepare.
The 2020 wildfire season in the United States is already unlike any other, and it’s far from over. More than 4.7 million acres have burned so far. California has suffered five of its largest fires ever recorded, while in Oregon, fires have consumed an area larger than the state of Rhode Island. Smoke and ash have saturated the air, and preemptive electrical shutdowns have left thousands without power.
These fires, worsened by climate change, have given Americans a sense of what’s ahead. And the records broken this year could soon be beaten. In a decade, 2020 will certainly be remembered as a historic year for fires, but perhaps not the worst.
Is climate change driving the U.S. wildfire crisis?
Climate change creates conditions that favor wildfires: hotter temperatures, deeper droughts, and drier vegetation. As the planet warms, fires start earlier in the year, last longer, and get bigger. Climate change is to blame for more than half of the increase in areas vulnerable to fire since 1984.
Climate change has fueled the crisis in states such as California by driving record-breaking temperatures. Hotter temperatures dry out soil and vegetation, creating favorable conditions for fires to grow and spread rapidly. An intense heat wave generated California’s hottest August on record this year, and in September, Los Angeles County reached its own historical peak of 121°F. This extreme heat, along with years of preventing forests from burning naturally, has resulted in fire-prone lands brimming with fuel. Highly flammable vegetation serves as a powerful propellant for fires.
With the continued warming of the planet, the likelihood of record-breaking heat events has increased for over 80 percent of the world, and these extremes will continue to intensify. This means that hotter, drier conditions will persist, leading to unprecedented destruction from fires.
Simultaneously, more people and property are at risk from wildfires than ever before. Building in the wildland-urban-interface (WUI)—areas adjacent to or intermingled with wildlands—has become the fastest-growing form of land use in the contiguous United States. A recent study showed that almost fifty-nine million homes within the WUI lie less than a mile away from where wildfires have occurred in the last twenty-four years.
What steps can U.S. federal and local authorities take to prevent or limit such destruction in the future?
The most important step in building resilience to future wildfires is immediately reducing greenhouse gas emissions. However, even if the United States successfully cuts emissions, it will still need to prepare for increased wildfire risk since current emissions have “baked in” temperature increases for at least the next several decades.
To reduce fire risk, state and local officials must require and enforce stronger building codes. Those codes should call for construction using fire-resistant materials and techniques. They should also establish defensible space around structures and firebreaks around entire developments, as well as designate evacuation routes. Where fire risk is extremely high, officials should consider restricting building altogether.
In addition, the federal government should stop subsidizing development in areas at high risk of wildfire. The U.S. Congress has already established a precedent for withholding financial support to at-risk areas through the Coastal Barrier Resources Act of 1982. That legislation is projected to save the federal government more than $100 billion in the next fifty years by preventing federal expenditures that encourage development in coastal areas at risk of severe storms and flooding.
State authorities should work to create a centralized early warning system, utilizing the most up-to-date scientific data and technology to forecast the potential for wildfires and issue evacuation orders. Early and accurate alerts will be critical to saving lives.
What lessons can U.S. officials learn from Australia’s historic fires?
Less than a year ago, Australia suffered its own fire tragedy: the Black Summer bushfires that burned more than forty-two million acres of land. A preliminary report [PDF] by Australia’s Royal Commission Into National Natural Disaster Arrangements, issued just days after the western United States ignited, found that land-use planning and building decisions are a “key factor” in determining the vulnerability and extent of exposure to bushfire. A Risk Frontiers analysis of some areas that burned found that “once a building catches fire, regardless of construction, it will likely be totally destroyed.” Moreover, analysis of prior fires showed that a building’s proximity to bushland is the most important factor in determining its vulnerability to fire.
Following the 2009 Black Saturday fires, Australia developed a wildfire early warning system. The Bushfire Warnings System alerts residents to hazards and provides three levels of warnings, which also include targeted evacuation and survival instructions. In the 2019–2020 fires, Australia’s warning system allowed residents to better prepare for and react to compounding climate-fueled events. Still, the royal commission recognized in its preliminary report that the system requires improvements. As the system is refined using lessons learned from recent fires, Australia’s warning system could serve as a valuable framework for such a system in the United States.