Wildfire: Climate, Settlement, Forests, Fire Management
Leader: Richard Seager
Thursday, November 9
About the Readings
Human Exposure and Sensitivity to Globally Extreme Wildfire Events
Bowman et al., 2017, Nature Ecology & Evolution
This paper reports that economically or socially disastrous extreme wildfires are concentrated in suburban areas intermixed with flammable forest in the developed world. Regional land use can reduce the occurrence of fire disasters. Climate change is likely to increase the frequency of extreme wildfires. The paper notes the pivotal role of meteorological conditions in driving extreme wildfire events, signaling increased global vulnerability to these events with climate change.
Wildfire Risk as a Socioecological Pathology
Fischer et al., 2016, The Ecological Society of America
Wildfire risk is increasing on a global scale, causing huge economic loss; nevertheless, fire is an essential ecological process. The authors define this as a socioecological pathology: a set of interrelated social and ecological conditions and processes that deviate from what is healthy/desirable. The authors use a coupled natural and human systems (CNHS) perspective to understand the pathology of wildfire risk in fire-prone temperate forests and suggest strategies to mitigate it. Finding solutions requires paying more attention to the interplay between social and ecological conditions and processes that influence human decision-making (wildfire governance system).
Learning to Coexist with Wildfire
Moritz et al., 2014, Nature
Policy strategies to address wildfires often emphasize fuel reduction; the authors state that viewing fire in the context of socioecological systems (SESs), recognizing the link between human and natural environments, provides insights into achieving a more sustainable coexistence with wildfire. This paper summarizes research on fire-prone ecosystems and fire effects on human communities through the lens of SESs. The authors suggest that context-specific and place-based approaches will be needed, and that greater attention to land-use planning is warranted.
Fire with respect to humans and human settlement is a problem that is becoming more intense in many regions of the world, especially semi-arid regions like the Western U.S., Australia, and the Mediterranean. Climate change makes the potential for fire worse, for simple physical reasons. Climate models predict the vapor pressure deficit will increase (defined as the difference in moisture between what the air has and what it could hold). Ecosystems and people do adjust to an overall drier mean climate. Extreme variability plays a role, but, everything else held equal, a warmer world should have more fire. Change in land use and revegetation also causes an increase in fuel. In the Northern Mediterranean, there seems to be an increase in fire that is occurring because of agricultural land abandonment.
The ultimate challenge is to adapt to fire, allow it to happen, and lessen the problem. We have to stop putting out fires, but how do we incentivize this?
The History of Fire in the U.S.
Within the U.S., fire was a normal part of most ecosystems prior to European-American interference in the late 1800s. In 1910, a series of enormous forest fires worried the U.S. government that repeated years with giant fires could put the country’s timber resources at risk. To protect these resources, the U.S. Forest Service adopted the ambitious and idealistic policy of suppressing all newly discovered forest fires by 10am the next day. Over the following decades, the suppression of fires allowed fuels to build up, particularly in the understory.
Today’s forests reflect this history, with large loads of fuels in the understory that serve as “ladder fuels” for fires to transition from low-severity fires that burn along the forest floor to high-severity crown fires that spread through the canopies of trees. In recent decades, we have seen that our interference has contributed to large, intense, and unmanageable forest fires. Even though tree-ring evidence shows that low-intensity fires were once normal components of forest ecosystems throughout much of the U.S., we still attempt to suppress the vast majority of fires, actively perpetuating the problem into the hands of future generations.
Federal costs of fire suppression have grown to be approximately $2 billion annually. The Forest Service fire budget is based on the 10 year average; more than half the budget is firefighting, and the U.S. taxpayer bears the cost. Even though there are huge areas of public lands where fires originate, the assets of value and infrastructure at risk are in private lands. The idea of fire as a coupled natural-human system has become popular, as fire critically affects human systems and human systems critically affect fire. Local governments are very interested in mitigating fire risk, as they bear the cost of fires, but land owners generally don’t want to be told what to do. Despite the public’s desire for autonomy, surveys show that the public generally views wildfire management as the job of the government. Public education is key to addressing the unsustainable approach to fire management in western U.S. forests, but funding for public education is not prioritized above funding for fire suppression, representing one way in which the western U.S. fire problem is self-propagating.
Insurance and Other Protective Measures
With fires, the insurance dynamic is tricky. Most insurance companies do not do aggressive work on wildfire because it doesn’t touch their bottom line. Their biggest cost for home insurance is hail. Hail happens multiple times per year and causes extensive property damage. Wildfire is catastrophic but rarer.
There are several nonprofits that work with homeowners to help them take measures to protect their homes. But for people who own a lot of property, these measures are incredibly expensive and won’t guarantee 100% protection. Insurance companies are slowly starting to offer rate reductions for people who do defensible actions.
Fire is a part of normal homeowner insurance programs (not so with floods). There are some rumors that insurers are threatening to back out of writing policy for fire. Some properties are uninsurable at any rate. It could become like flood insurance, with the government subsidizing it leading to political disaster. When private insurers stopped writing policy for floods, the government took over and NFIP was created. However, it is likely very far away for fire insurance, as fires aren’t putting insurers out of business. If fires grow faster and become more frequent, this could change.
Limitations to Modeling Fire
Our ability to model fire and project it in the future is still pretty poor. There are not long records of global fire data, and future predictions require a lot of parameterization. We still infer a lot about future patterns, and we are not yet modeling the actual sequence of events. Additionally, parcel level data doesn’t exist, and it is always changing based on its surroundings. Good, high-resolution fire spread models that update dynamically as landscape changes would be very useful, but we are nowhere close to this.
Fires, Floods and Retreat
With floods, rebuilding is the high cost. With fire, the big cost is firefighting. We try and stop fires, but we don’t try and stop floods. Another difference is that when you rebuild in a fire zone, there is no high risk until the vegetation recovers; in flood zones, the risk remains. Post-Sandy, a couple of communities in Staten Island were bought out – one was even moved to a different location. But what are the secondary consequences of retreat vis a vis tax rates, schools, etc.? Buy-out is complicated and doesn’t happen much.
Relatedly, a tax or fee for living in a higher risk place wouldn’t work for fire, because that parcel level data doesn’t exist. We can’t show that one particular house or piece of land corresponds to a specific risk ranking. Home builders and realtors are very much against this.
People have an attachment to place and don’t want to move. Human nature is to rebuild rather than retreat. More and more people want to live in these wild-urban interface areas (amenity-seeking migrants). Strategic retreat is not discussed in relationship to fire.