When discussing any particular disaster and its relationship to Global Warming, one needs to be cautious, to avoid saying “Global Warming caused X” as it is quite difficult to show a direct cause and effect relationship with a global trend to any particular activity. Thus, stronger storms are correlated with rising temperature which correlated with a storm like Katrina. Did Global Warming cause Katrina? Who knows? Was Katrina’s strength, differentiation from past storms, within what Global Warming analysis/modeling suggests could happen? Yes.
Well, be careful if anyone says that Global Waming “caused” the California fires. On the other hand, it seems clear that Global Warming is a contributing factor to the conditions in which the storms have occurred. As per Daniel James Brown’s OPED, Smarter ways to handle fire,
increased fuel loads in our wild lands are only one element of a converging series of fire-related threats that now challenge us in unprecedented ways. Our penchant for building homes in fire-prone areas is another obvious and much-discussed factor. And a third, now undeniable, one is the role that global warming plays in raising ambient temperatures, promoting drought in already drought-prone regions and lengthening our fire seasons.
The scientific analysis of US fire records clearly show changed patterns, with a strong correlation in terms of increased fires and Global Warming trends.
Tom Setnam, a University of Arizona Professor and a leading ‘fire ecologist’, notes that
“The fire season in the last 15 years or so has increased more than two months over the whole Western U.S. So actually 78 days of average longer fire season in the last 15 years compared to the previous 15 or 20 years …”
Scripps Institution of Oceanography and Univ of Arizona combiend work looked at the forest fires from 11 Western states over a 34 year period “and found the number of fires increased in size and severity since 1987, the same year that spring and summer temperatures began to rise.” They examined every forest fire that burned at least 1000 acres from 1970 through 2003. Of 1166 fires in that period, nearly 900 occurred after 1987 — e.g, 80% after the mid-point in time. And, well, “they also found that air temperatures from 1987 to 2003 were 1.6 degrees higher than during the previous 17 years; that 6.5 times more acreage burned during that warmer period.”
According to the head of the US Government’s firefighting programs, “We got records going back to 1960 of the acres burned in America. So, that’s 47 fire seasons. Seven of the 10 busiest fire seasons have been since 1999.”
Very simply, from the National Wildlife Federation’s analysis of Global Warming’s likely impact on the American West, Fueling the Fire,
Another serious consequence of global warming in the West is an increase in the incidence andseverity of wildfires, a problem made even worse by decades of fire suppression, extensive grazing and other factors. …
there has been a four-fold increase in the number of major fires each year and a sixfold increase in the area of forest burned since 1986 compared to the period between 1970-1986.
One study, for example, projects that the overall area of acreage burned will double in size across 11 western states if the average summertime temperature increases 2.9 degrees Fahrenheit between 2070-2100.
Again, it is impossible to state that Global Warming did or did not cause the California wildfires.
The flames that we see on television. The burned homes. The billowing smoke clouds. Global Warming is not the cause … or at least not the sole cause.
Global Warming did, however, contribute to the conditions for these fires and, well, could be said to be fanning their flames.
It is time to stop fanning the flames.
Energy Smart 
Great post on this subject over at Orcinus … recommended: The ‘adjustment’ in San Diego http://dneiwert.blogspot.com/2007/10/adjustment-in-san-diego.html
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No, global warming did not cause our fires.
It appears that at least a few of them were caused by arson though.
I’m sure the voting history of the people of San Diego will be interesting though, they’ve had woefully underfunded fire departments for years.
I’m not looking forward to the (inevitable) tax increase to pay for all this.
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Is a sows ear a purse?
Average daily temperatures that increase over several years may increase a given fire season burn intensity. Without a fire intensity record on a given tract of land, averaging observations may distort the big picture. Record keeping of fire physics-burning values are relatively new. Existing post fire analysis via ICS documents do not thoroughly allow individual observations of the tactical (those up close and personal) function to relate burning intensity values.
What may also contribute and be important to establishing the intensity of a given year is the precipitation not only in volume, but also how – when – where the precep occurred on a given year.
In California the 1977 fire season occurred during a Drought Year.
Fires may only be controlled under certain topographical considerations (terrain) and favorable weather (wind, temp). The accumulation of dead down fuel load on our public lands will make fire control more difficult. Terrain features that support control lines – ridge tops need as a minimum a fuel break. In past these ridge tops were conveniently maintained as fuel breaks via the then normal 60% sustained harvesting practices that no longer exist. Fire supportive contractors – logger-yellow McLouds were 3 decades ago in place on every NF west of the Rocky Mountains during the summer months. In its place are now years of dead fuels accumulation and a Forest Service personnel infrastructure that is at basement levels (Congress). Add to this mix the surge of new homes in the interface wild land areas. This alone compounds control considerations.
The ‘Let Burn – no burn’ policy of the 1970s may have contributed to size and intensity of some of these fires. There still is a lingering attitude supporting the 70’s flawed burn-no burn decision.
Extract the Homes-Evacuations of this early 2008 fire season, there is a resemblance of prior fire season years. TV may be a larger indicator of “more intense burning”.
Snow depth of 2008 Sierra-Cascade junction area was just under normal. It contained only a small percentage of water that is “normal for Sierra wet snow. Melt was rapid during a dry warm spring allowing faster earth temps to rise. Did the colder winter make dryer snow?