The water shortage crisis in large parts of California is almost always referred to as a drought, which of course it is. Yet this has tended to divert attention from the increasing desertification happening in parts of the state.
Desertification can be the result of any one of several factors or combination of such. Yet deforestation is one precipitant of desertification -- or it develops into a tipping point; i.e., if a macro weather system is creating a trend for arid conditions in a region, deforestation can exacerbate the trend. This kind of situation relates as much to micro climate as macro climate.
Critical Importance of Microclimates
In a post last year about widescale mountaintop removal in the Appalachians I noted that scientists studying the environmental impacts of the mountaintop removals had started speculating that the removals, which can include destruction of large swaths of mature forests,were be negatively affecting the entire microclimate in the region. The scientists were launching research to study this angle.
The same kind of research might yield a new view of the drought in California's San Joaquin Valley. It would also be helpful to know if there's a correlation between the recent widescale deforestation in the region to make way for large commercial marijuana (pot) growing operations and the desertification in the region during the past 3-4 years.
Of course the greatest damage in this regard over the long term in California would be due to establishing larger and larger fields for food crops. But the biggest problem with the influx of large-scale marijuana farming into the Central Valley -- particularly the San Joaquin Valley -- during the past few years is that there aren't 'fields' that can be readily spotted by authorities. Many farmers in the Valley who grew food crops started interspersing them with larger and larger stands of marijuana plants.
As to how much deforestation has occurred in the state that specifically relates to commercial pot farming, I don't think that's been nailed down. But from this February 2014 report by Jason Best (Marijuana Farms Push California Salmon to the Brink of Extinction) it's been extensive.
In the almost 20 years since California legalized the sale of medicinal marijuana, thousands of new growers have set up shop. An aerial tour using Google Earth created in 2011 by Anthony Silvaggio, an environmental sociologist with Humboldt State University, and posted by Mother Jones, shows some of the devastating impact, with large swaths of forest mowed down to make room for illicit grow operations.However, the deforestation from large scale marijuana growing that Silvaggio chronicled is in the north of the state -- in Humboldt County, part of California's pot-growing "Emerald Triangle." Not in the Central Valley.
Speaking of deforestation and mountaintop removal, it so happens that environmental damage done by the removals is of the same kind that happens with large scale marijuana cultivation: deforestation, dammed and diverted rivers and streams, streams filled up with dirt, polluted freshwater and groundwater, etc.
It further happens that the mountaintop removal 'belt' in Appalachian states is also home to large scale illicit marijuana operations. Yet to my knowledge there has been no study of the correlation. In fact, published studies of the environmental impact of marijuana operations in the Appalachians are scarcer than hen's teeth.
How Numerous Lost Jobs Can Impact Microclimates
I think there's a reasonable explanation for this. When the strip mining operations associated with mountaintop removal replaced regular deep mining, many coal miners lost not only their job but also their vocation. And since the 2008 financial crash, it's been even harder to find employment in the poorer U.S. states or regions in the Appalachians. The result is that the state governments, facing high unemployment numbers, tended to look the other way about the proliferation of illicit pot growing operations.
And whatever environmental damage was due to pot growing could easily be chalked up to the mountaintop removal operations, and probably has been in several cases.
A parallel situation happened in California in areas with widescale logging operations. As the operations were permanently wound down on a large scale, people who'd earned their living in logging, and couldn't find other employment, turned to pot farming.
During the weather's salad days these ways of earning income, no matter how destructive to the immediate environment, have to be tolerated. But when the weather pattern turns against humans, whatever microclimates that result from human activities begin to take critical import. A vicious cycle can occur, in which the micro climates steadily worsen as droughts from a macro climate pattern increase.
Eventually the cumulative effect of the degenerated micro climates impacts a macro weather pattern. At that point an entire continent can be put at risk.
Dope, Wildfires, and Deforestation
Accurate statistics about the relationship of outdoor marijuana farming to wildfires would be impossible to come by. Only recently, as the drought settled in for the long term in California, have state and local officials become more forthright about the situation.
However, these two articles from September 2014 highlight the seriousness of the situation and how it feeds into drought and desertification cycles that can alter micro climates: King Fire Points to California's Drought Driven Fire Future (Video) (Christian Science Monitor) and California Wildfires, King Fire, Drought And Climate Change (National Geographic). I'll toss in this CSM report from June 2014 about hi-tech firefighting that I found interesting.