I mentioned in my post earlier today that one effect of global warming in California has been an intensification in the destructiveness and frequency of wildfires. Today the US Geological Survey provided further evidence in support of that fact:
USGS researchers found that southern California is the only part of the state that has experienced significant increases in wildfires over the last five decades. Analysis shows that this increase is linked to the rise in atmospheric temperature. Past studies suggest that wildfire activity has increased throughout the western United States. USGS researchers wanted to know whether this pattern has region-specific variations and causes. For the analysis, they divided California into five climate zones and looked at how number of wildfires and area burned have changed over the past 49 years. But this study did not find statewide increases in wildfires. Only southern California experienced increases in fires and area burned. Curiously, the increases are not linked to that region’s enormous change in population growth. However, for northern California, analysis shows that wildfire trends have links to population trends. This research gives new perspectives on wildfire trends in California. The results will inform urban and natural resource planners on their long-term outlook on wildfire management.
In short, while population growth is a known factor in wildfires around the state, Southern California’s experience suggests global warming is the primary factor there, where millions of people live with the threat of a wildfire burning down their home.
In the fall of 2007 a San Diego Reader article explained how global warming leads to more fires:
Duncan McFetridge’s oaks and others suffering in the Cleveland National Forest get none of the Sacramento water. And trees are thirsty creatures. They say that a mature oak tree needs 300 to 500 gallons of water a day. But you have to wonder: these trees must have endured droughts like this before, and now they must have more capable roots than ever before. How is it they’re succumbing?
Orrin Davis, whose company Butler Drilling has been drilling water wells in the mountains east of San Diego since the 1960s, says oaks are vulnerable to changes in the water table. “Back in the ’70s, ’80s, you’d have to drill down an average of 400 feet to reach water. Today, it’s 800 to 900 feet. I’ve had to go to 1400 feet. In my 40 years, this is one of the longest droughts. As far as I’m concerned, this drought has been going since the early, mid-’90s.”
He says the die-off has been going on for years. “If it’s true that this is the worst drought for 500 years, these are drought conditions these oak trees have never experienced. And I would estimate Duncan’s oaks were 300 to 400 years old, the bigger ones.”
A hotter climate leads to less rainfall. As Steven Chu explained it to the New York Times in October 2007, before he became Obama’s Secretary of Energy, global warming will strain water supplies in California:
even the most optimistic climate models for the second half of this century suggest that 30 to 70 percent of the snowpack will disappear. “There’s a two-thirds chance there will be a disaster,” Chu said, “and that’s in the best scenario.”
California’s own climate change study confirm this. And it cascades throughout Southern California – the lack of rainfall causes a cascade effect on water supplies and, consequently, on vegetation. Without rainfall, cities and developers have to draw down already-stressed aquifers, depleting the soil moisture that helps keep plants somewhat watered even in the dry months. As this is drawn down, the ongoing lack of rainfall means the aquifers aren’t getting replenished. Stresses on the Colorado River mean California must reduce its share of water drawn down from the river. And the ongoing problems with the Sierra snowpack and the Delta mean that Southern California gets less water delivered – reinforcing the stress on groundwater.
In turn, this leaves less water available for vegetation, which is therefore more vulnerable when wildfires inevitably start up in October. Instead of a wildfire being small and more easily contained, water-stressed vegetation fuels the fire’s growth into a major catastrophe.
It’s a situation that cries out for action. That is, unless you’re a Texas oil company or a right-wing global warming denier, who backs Prop 23 despite this destructive impact of global warming on our state.
Actually, a hotter planet means more humidity in the air which means stronger rainfall in most places, but also faster evaporation (thus more wildfires). Since the rain comes all at once, it doesn’t percolate to the water table as much as it would with weaker, more frequent rains the trees are used to (also, the more trees die, the less the soil is porous, the more rain just washes away along with even more topsoil).
As Chu said, the problem with water supplies is that less snow falling on our mountains and the snow melting all at once due to heavier rains.
Wildfires and water scarcity have different causes, even though both causes are exacerbated by the warming climate.
Either way, proponents of Prop 23 are genocidal maniacs that will be responsible for the demise of the American Southwest (not to mention the rest of the planet).
Walley Herger R CA. D2 is a global warming denier who wants to help BP drill more! He said there is no truth in global warming warnings! One of the riches members of Congress who is brought and paid for by the oil, insurance etc. companies. It is time for Walley to go. Jim Reed D from Fill River Mills is running to help remove Walley.
Can you help: www.reednow.com