Dealing with Forest Fire Risk
Guest essay by Don Healy
Looking out on smoke and ash filled vistas while reading about the Carr, Mendocino and numerous other forest fires raging through the Western U.S. and British Columbia creates a great deal of concern and some physical discomfort. Fire is a natural component of our wild areas. Historically, the average acreages burned were much higher in the early 1900s, averaging about 25 million acres, maintaining relatively modest levels mid-century of about 4 million acres, and then trending upwards from the 1980s to the present time. Over recent years, the acreage burned by forest fires in the U.S. has fluctuated between and 3.5 million and 10 million acres per year. Obviously, climate change had nothing to do with much larger burns early in the 1900s, and is most likely a small factor currently.
In recent years however, we are seeing much greater property destruction and loss of life as development continues to encroach on the wildland-urban interface. Each summer, we go into panic mode, but rather than trying to get to root of the problem, and reducing the likelihood of large conflagrations in the future, we are expending massive amounts of money trying to contain the fires that occur. Unfortunately, this is a battle that we cannot win with the current methodology. The reasons are as follows:
1. We all remember the fire triangle with the three legs of oxygen, heat (ignition) and fuel. In this case, the problem boils down to the fuel component; we have far too much of it and the quantity is growing quite rapidly, for primarily two reasons. We quit harvesting timber in the late 1970s on federal lands in the western United States, and currently have 57% more standing timber than we did in 1953. That is correct – 57% more; much of which is stagnated and impacted by insect and disease issues. This larger fuel supply will simply continue to grow unless we are willing to reengage in reasonable forestry practices such a selective cutting and thinning, which would necessitate the building of new sawmills and wood product plants and would provide thousands of jobs at the same time. Stand treatments to simply reduce the fuel load are very expensive and need to be combined with a revenue generating aspect if we wish to accomplish our goals in a timely fashion without bankrupting ourselves.
It should be pointed out that this table includes only merchantable timber. The actual fuel load includes a large amount of smaller material that has probably increased even more rapidly.
2. Many point their fingers at the issue of temperature increase due to climate change, and while this does have a very modest contribution to fire risk, the biggest effect is actually a more hidden one. In fact, a major component of the current fire problem is that the increasing levels of CO2 in the atmosphere have two beneficial effects on both crop production and the same vegetation that fuel wild fires, such as trees, grasses and chaparral. The first beneficial effect is CO2 fertilization. A recent study by NASA shows a significant greening of the planet over the past years, which buttresses the laboratory studies on the effects of CO2 fertilization. (https://www.nasa.gov/feature/goddard/2016/carbon-dioxide-fertilization-greening-earth)
The second beneficial effect is that trees and plants become more drought resistant with increases in CO2 levels. This further compounds the issue of increasing fuel loads. The trees and plants become more drought resistant, but not necessarily more fire resistant.
Many articles claim that climate change is the driving force behind the increase in wild fires. However, I think we all realize that there are multiple factors at work here. Looking at the most accurate temperature record for the United States, the U. S. Climatological Research Network (USCRN), shows no significant trend for the 12 years since it went into service. This network is state of the art with excellent siting of stations coupled with triple redundancy.
Other longer term records such as the UAH satellite record indicate a very slight increase in the temperature trend; about 0.4 degrees Centigrade from 1979 to the present. (http://www.drroyspencer.com/2018/08/uah-global-temperature-update-for-july-2018-0-32-deg-c/) While the mid-1980s to present trend line for fuel loads correlates with the trend line for acres burned in the U.S., the temperature record shows virtually no correlation.
As additional verification of the effects of CO2 fertilization at the most practical level, we can look at the yield per acre figures for some of our most common crops, as obtained from the USDA at https://www.nass.usda.gov/Charts_and_Maps/Field_Crops/.
Looking at this situation in gross numbers, the western U.S. contains about 1,008,000,000 acres of land, with varying types of vegetative covering. Assuming that each acre is relatively uniform on average, the additional growth due of CO2 fertilization is equivalent to the total growth on 151,200,000 acres of land. (This is using a 15% rate of additional greening; the low end of the figures shown in the citation above.) Assuming the higher quantity of acres burned per year mentioned above, of 10,000,000 acres, we can see that we are gaining over 15 times the fuel load that we are losing to wild fires, and the situation will be most like get more dire over time, because for plants, we are still close to the low end of their preferred CO2 ranges, and will see even higher results from CO2 fertilization effect for at least another doubling of CO2. A quick review of this effect upon the fire problem will show that ignoring this problem will only make it worse, far worse.
In addition to implementing sustained-yield forest practices on our forest lands, we also need to address the effects of ourselves and our fellow humans’ desire to life within the bucolic beauty of the wildland-urban interface. This also has at least two aspects that must be addressed in these situations:
1. Building codes need to be modified to require that structures built in the wildland-urban interface be far more fire proof. Code should require:
A. Fire proof roofing such as steel and ceramic tile.
B. Siding of fireproof material such as brick or stone.
C. Roof venting either closeable or require mesh sufficient to prevent wind-blown embers from entering the attic space. (This was a major factor in the recent Santa Rosa, California fire.)
D. Removal of flammable vegetation and landscaping materials such a bark from areas near structures.
2. In the open areas in the wildland-urban interface, these steps should be implemented:
A. Thin natural vegetation and create fire breaks where necessary.
B. Limit or ban construction in areas of extreme vulnerability.
C. Construct water retention facilities such as ponds or reservoirs along with the necessary pumps, generators and hoses.
For both provisions 1 and 2 above, it will be necessary to have regular checks and inspections to insure that the appropriate conditions are maintained.
Some insurance companies are already taking steps to insure that some or all of these safeguards be taken if homeowners wish to obtain or continue coverage.
Conclusion: Time is of the essence in dealing with our wildlands fire dilemma. The crucial factor that needs to be addressed is the high and continually expanding fuel load in our wild areas. We have the means to deal with this issue and could commence in the very near future. It could also be accomplished in a way that would improve the health of our forests, provide jobs, provide revenue for our local counties for schools and roads, and other economic benefits. Also, we need to recognize that while the issue of climate change does bear upon this situation, we simply can’t wait to get started down that path to solve the fire problem. China, India and other nations are heading in a contrary direction and it will be decades at least before we will see a meaningful reduction in CO2 levels. We need to do immediately, what it is feasible to accomplish.