Playing with fire: How we can prevent wildfire climate change catastrophes

Drought conditions have again spread across California and the Southwest only four years after the end of the most intense drought in modern California history. As landscapes dry out, the threat of wildfire increases, and threat levels are already high. Three of the last four wildfire seasons shattered previous records in terms of acres burned in California and across the West. 

Earlier this year California Gov. Gavin Newsom (D) and state legislators announced a plan to allocate over half a billion dollars to reduce the threat of wildfires to the state. Money will be spent reducing the amount of wildland vegetation available to burn, hiring additional firefighters, and helping homeowners protect their properties. 

These steps are essential and welcome, but more can be done. An increased commitment to sustainable climate solutions is necessary to limit the warming and drying trends that feed increasingly extreme and destructive wildfires. Affordable housing in urban areas is needed to slow the sprawl of development into dangerous fire-prone areas.

Our problems have been a long time in the making. A century of wildfire suppression across the western U.S. has increased fuel loads to critical levels. Years of record dry heat caused by the changing climate have turned western forests and wildlands into a multi-gigaton tinderbox. Now a single bolt of lightning, downed powerline or careless act can cause catastrophic losses of life and property, as witnessed in the town of Paradise in August 2017 or the town of Berry Creek last September.

What was historically a seasonal problem has become a year-round threat. Research from Scripps Institution of Oceanography at UC San Diego finds that weather patterns in California are changing. In Southern California, Santa Ana winds are projected to weaken in the fall and spring but remain strong in the peak winter season. With delayed fall rains, hazardous wildfire conditions will persist longer and later into the winter. This was the case in the December 2017 Thomas Fire. A strong and lasting Santa Ana after months without rain led to the largest wildfire in Southern California history. When rain finally came in January, the fire had stripped the slopes of vegetation leading to devastating debris flows in Montecito, California that killed 23 people.

The economic costs of wildfires are rising. Three of the past four fire seasons cost over $10 billion in property loss and suppression costs. But there are other less obvious costs associated with wildfire, including the health burden associated with wildfire smoke.

Our research has shown that wildfire smoke in Southern California can be more harmful to human health than similar levels of fine particulate matter from other sources of pollution. While the U.S. has significantly reduced air pollution from traffic and industrial plants in recent decades, smoke events have been increasing in frequency and severity, putting millions of Americans’ health at risk.

Policymakers, fire managers, scientists and community groups understand that there is no silver bullet. Increasing spending on prescribed burns and fuel treatments to match spending on suppression will reduce fuel loads. Helping homeowners to clear defensible space around their properties will protect homes and reduce risks to firefighters. Providing masks and air filtration systems to high-risk populations and protective equipment for those who work outdoors will help protect against wildfire smoke. 

While steps are now being taken to reverse decades of inaction on climate change, we must accept that predictions about the damaging impacts of climate change are coming true. Policies based on historical weather patterns must be updated with more forward-looking strategies. Interactive climate data visualization tools like Cal-Adapt, which show projected changes in sea level, extreme weather and wildfires, will be critical in shaping policy.

The rise in extreme wildfires, heatwaves and floods at home and abroad should remind us of our profound impact on the natural world and its impacts on us. New policy efforts at the state and national levels to address climate change are encouraging, but these collective efforts must be strengthened and sustained if we are to avert the worst outcomes and protect the most vulnerable.

Tom Corringham is a climate researcher at Scripps Institution of Oceanography at UC San Diego. 

Rosana Aguilera is a climate researcher at Scripps Institution of Oceanography at UC San Diego. 

Janin Guzman-Morales is a climate researcher at UC Santa Barbara.