Causes and Potential Solutions to the LA Wildfire Disaster
By Patrick Brown
A version of this article was originally published by City Journal, you can read that here.
Devastating images are emerging out of the Los Angeles area depicting the immense destruction of several fires that are raging through communities this week. These fires are likely to be the costliest wildfires in US history, overtaking the 2018 Camp Fire that destroyed Paradise, California.
Many are looking for a clear culprit to blame for this disaster, with climate change being one of the most popular. This disaster, however, is the result of a confluence of natural and human-caused factors. Climate change may be playing a role, but a narrow focus on it could be counterproductive as it distracts from more direct measures to reduce fire risk and impact.
Is climate change the culprit?
Fire danger is a product of meteorological and fuel conditions. You also need an ignition—you can't start a fire without a spark. Global warming from fossil fuel burning raises temperatures relatively uniformly and thus affects all aspects of meteorology relevant to fires to some degree, though often not in the same direction.
These fires are being driven by a particularly intense Santa Ana wind storm with widespread hurricane-force winds and gusts over 80 mph in some places. These winds are the primary meteorological driver of the disaster: they provide the oxygen needed for burning, drive flames forward, spread embers, and can make aerial firefighting impossible.
Santa Ana winds are an innate part of southern California's climate, and there is little evidence that climate change will make them worse. If anything, we expect Santa Ana winds to become less intense/frequent as the climate changes.
Fires need something to burn, so the state of vegetation (the fuels for fires), and in particular how dry that vegetation is, is the other key ingredient for fires. The Los Angeles area has received much less rain than normal for this time of year, which makes vegetation more flammable. However, there is little evidence that warming is a primary driver of a lack of precipitation like what we have seen this year.
However, when Los Angeles does see droughts like this, a warmer climate means a drier atmosphere, which works to dry vegetation and makes vegetation more flammable.
Is vegetation the problem?
Then, there are the characteristics of the vegetation on the ground, such as how much fuel there is for fires. The situation in Southern California Chaparral brush is different than in the forests to the north (where a major problem is fire exclusion and the century-long build-up of overstocked forests). Nevertheless, mechanical brush removal and prescribed burning can still be used to reduce vegetation and fire danger, though it can come at a cost to ecosystems.
So, how effective would proactive vegetation reduction be in the face of continued warming?Our research seeks to answer this question. The procedure takes conditions over the course of a fire, warms the background climate, and simulates vegetation reduction to see how future warming and fuel treatments would simultaneously affect a fire. Below is what this looks like when applied to the weather in the Los Angeles area this week.
Our modeling indicates that warming is indeed contributing to increased wildfire intensity in the region, with a further enhancement by mid-century.
It is important to note that two different greenhouse gas emissions scenarios are shown. One is a slow emissions reduction scenario that roughly represents current global policies (SSP2-4.5), and one represents fast emissions reductions that are much more aligned with the Paris Agreement (SSP1-2.6). The movement from the slow emissions reduction scenario to the Paris Agreement scenario represents major differences in the global energy and agricultural economies, technology adoption, geopolitics, etc. Yet, these differences translate into only marginal changes in 2050 fire intensity (from +7.2% to +5.5%).
When it comes to addressing wildfire risk, reductions in greenhouse gas emissions are often heralded as the primary lever we can pull. However, trying to influence weather-related outcomes through energy policy is incredibly indirect and there are often much more direct solutions at hand.
In that vein, the blue bar represents fire intensity in 2050 under slow emissions reductions (4.5) but with proactive vegetation reduction. We see that even in a situation of 2050 warmth, under a slow emissions reduction scenario, vegetation reduction would reduce fire intensity by about 15% relative to today.
This is evidence that California’s goal to increase hazardous fuels reduction treatments to 1 million acres per year, along with the federal government’s target of reducing fuels on 50 million acres over a decade, are laudable and would be helpful in combating the growing wildfire threat.
However, actually achieving these goals requires overcoming multiple challenges, including funding constraints, workforce shortages, and logistical issues related to complex land ownership patterns.
Finally, there are bureaucratic and regulatory obstacles associated with the California Environmental Quality Act (CEQA) on California state land and the National Environmental Policy Act (NEPA) on federal land. The NEPA process, in particular, is associated with significant obstacles to fuel reduction treatments. The Forest Service writes the most NEPA reviews of any federal agency and is the most likely to be sued, resulting in litigation that delays project implication by about 3 years on average.
Human Ignitions
All these fires were lit by people, and thus, the huge population of southern California provides many ignition sources that would not be there naturally. Common causes are equipment use (sparks from chainsaws, mowers, etc.), sparks from vehicles, ATVs, dirt bikes, smoking, campfires (or fires in homeless encampments), BBQs, fireworks, and Arson. Thus, Increasing public awareness of fire safety and red flag warnings should help reduce these ignitions, and this is actually the case as human ignitions have probably decreased over the past several decades.
There is also the issue of utility-caused fires. Southern California Edison has preemptively shut off power in several regions to reduce the risk of powerline-caused fires. This is not an ideal solution, but it does prevent ignitions. In the longer term, we can continue to reduce vegetation around power lines, bury distribution lines, and install powerlines that automatically de-energize when they make contact with an object.
Home hardening & firefighting.
Given that extreme fire weather conditions like this will inevitably occur and given that human ignitions cannot be eliminated, protection at the structural level is also important. Houses are much more resilient to fires if they have no vegetation within 5 feet of the house, and vegetation is fire-resistant and sparse from 5 feet to 100 feet. Building codes and “home hardening” also make a difference. Things like non-combustible roofing materials (e.g., metal, tile, or asphalt shingles), ember-resistant vents with mesh screens, and fire-resistant materials for siding (like stucco, fiber cement, or metal) have been shown to be effective in the lab as well as real-world settings. There is also a synergistic effect, with increased overall effectiveness, as more houses in a neighborhood adopt these practices.
Also, it goes almost without saying that well-resourced firefighting (personal as well as air and ground equipment), as well as high-quality fire-weather forecasting, are critical to slowing down and ultimately containing fires like these.
Overall
Devastating events like this leave many to search for a simple villain to blame, but the reality is often much more complicated. Climate change may be contributing to some increase in fire danger in this case, but its lack of influence on the high winds and drought means that it does not deserve central billing. Furthermore, the effects of global emissions reductions on fire activity are quite indirect and delayed.
Fire suppression and the long-term build-up of fuels are not an issue in brush landscapes the same way that they are in the Northern California Forests, but our modeling indicates that vegetation reduction would still be able to appreciably reduce fire danger in these landscapes.
Apart from those measures, the main way these types of events can be mitigated in the future is via further reductions in human ignitions, potentially increased firefighting resources/technology, and enhanced “home hardening” measures within fire-prone communities.
Ultimately, we live on a planet that is often hostile to our well-being no matter what we do. Southern California is a region that has been very fire-prone throughout human history, and it will continue to be so indefinitely. Thus, devastation from natural disasters cannot be completely avoided, and we are often left with partial measures that are only able to reduce rather than eliminate risk.