The total number of Acres Burned in California have increased and decreased over the Decades with a range of less 50,000 Acres to 1,600,000 Acres. The increases and decreases follow the Pattern of Rainfall. Increased Rainfall promotes the growth of Grasses and Shrubs at ground level. Subsequent years that produce less rainfall, or create Drought conditions, cause the New Growth to die, and the dead plant material is Fuel for next Wildfire. If the dead plants do not burn the year that they die, they will build up over subsequent years of little rainfall, and extreme rainfall, until an Ignition source is provided. The ignition source could be natural, lightning, or it could be accidental, campfire, etc., or it could be Arson. The Source of Ignition is not important. The extremely combustible material WILL ignite eventually. The only questions are, when will it ignite and how many acres will burn?
California Wildfires Per Year
The number of California Wildfires has Decreased from a high of 13,476 in 1987, to 9,133 in 2017. The years from 2002-2016 had the fewest number of Fires per year over the past 30 years. The number of Wildfires was less than 9,000 per year for each of those years.
Years with Rainfall well above average, are followed by years with more Acres burned.
The increased Growth created by the very high rainfall creates more Fuel in the following years when the rainfall decreases back to the Yearly Average or below. High Rainfall years are quite often followed by extremely Low Rainfall years, leading to the Drying of much of the New Growth.
California Wildfire Acres Burned Per Year
The greatest number of California Wildfire Acres Burned were in the years 2007 and 2008. These were the years following the Record or near Record Rainfall throughout California in the winter of 2004-2005. The Extremely High Rainfall created significant amounts of new growth. The growth did not dry out as it usually does after a High Rainfall Year because 2004-2005 was an Extreme Event that saturated the Soil and kept the plants and undergrowth Green for a couple of years. The Rainfall Year 2006-2007 provided less than 5" of Rain, allowing the Soil to Dry and the Plants to Die, creating Very Large Amounts of Fuel for the following year's "Fire Season".
The Pattern of Rainfall, California Wildfire Acres Burned and California Wildfire Acres per Fire follow the same Pattern in the available Data from 1987 through 2018. This indicates that the Wildfires that California has been having are not caused by Climate Change, but are a Natural Phenomenon associated with the Mediterranean Climate that Californian's enjoy. Southern California is a Semi-Arid Region with a year of Heavy Rainfall followed by several years of Very Little Rainfall, and Drought Conditions.
Los Angeles Rainfall: 1981-2018
In the Winter of 2004-2005, most of California received Record, or Near Record, Rainfall. The following year, 2005-2006, the rainfall was only slightly below Average. This kept the Brush and "UnderGrowth" from drying out, and providing extremely Combustible Fuel.
The winter of 2006-2007, was a Record, or Near Record, low rainfall. Los Angeles rainfall was only 3.21" that year.
2004 was a year with the number of California Acres Burned well below average. 2005 was another year with the number of California Acres Burned well below average.
2006, the year after the Record, or Near Record, rainfall, the number of California Acres Burned more than Tripled.
The following two years, 2007 and 2008, the number of California Acres burned were more than FIVE TIMES the number of Acres Burned in the previous 2-3 years.
In the Late 1970's, early 1980's, the California Local and State Firefighting Agencies, and the Federal Firefighting Agencies, implemented Improved Fire Suppression Techniques. These Improved Fire Supression Techniques extinguished the Wildfires much more quickly, with far fewer Acres Burned.
This caused future problems by allowing the Undergrowth to accumulate for 15-20 years rather than the Brush in the Forests burning every 5-10 years.
This extremely high level of Combustible Materials resulted in Larger, Longer Burning Wildfires in some areas. These Larger Wildfires are not necessarily a result of Climate Change, but a result of Poor Forest Management.
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