Prolonged periods of hot weather and drought create ideal conditions for difficult-to-fight forest fires. [emphasis, links added]
Although climate models predict that such weather conditions as a result of human-caused global warming will increase the incidence of wildfires, the recent wildfires cannot be entirely — or even primarily — blamed on global warming: The weather conditions that cause forest fires have existed for thousands of years due to naturally occurring climate cycles.
For example, research shows Over the past 3,000 years, the American West has experienced severe fires in the 1800s and the Medieval Warm Period (950-1250 AD)and Some of the least destructive events occurred in the mid-20th century and during the Little Ice Age (1400-1700 AD).
Natural climate change has clearly altered the severity of historical fires, but landscape changes and similar human impacts—Includes logging and farming practices, firefighting practices, building rail lines and electric grids, livestock grazing, clearing forests for farmland and settlements (including modern suburbs), intentional burning for agriculture, increased recreational use of remote areas, and the intentional or unintentional introduction of stray animals Grasses, non-native herbs and shrubs– Over time, especially since the 1800s, the behavior of wild animals has changed, affecting their behavior.
The strongest data assessing changes in modern forest fire severity over time in the contiguous United States come from the western states (Arizona, California, Colorado, Idaho, Montana, Oregon, New Mexico, Nevada, Utah, Washington and Wyoming), these states have comparable records going back to 1916.
The records show that on federal and federally protected lands, fires from 1916 to the mid-1940s (excluding fires caused by arson) were similar in size to fires in the early 2000s.
The most acres burned in 2012 But the second highest number of fires occurred in 1919, and there were a number of fires before 1932 that were comparable in scale to recent events.
Overall, as you can see from the chart below, there is no clear trend over time.
Records show that most forest fires (Including arson, unattended campfires, discarded cigarettes, sparks from electrical wires or machinery, etc.) Whether intentional or not, these are initiated by people and have largely been the case in North America for hundreds of years.
For example, in the fall of 1825, a huge forest fire broke out in Maine, with various causes attributed to loggers burning cut piles, settlers using fire to clear farmland, and federal agents setting fire to hay cut by illegal loggers. Feed for livestock.
In 2021, 75% of wildfires in Oregon and Washington were determined to be human-caused, up from the previous 10-year average of 64%.
Arson is a troubling subset of human-caused wildland fires, and the intentional intent that defines these fires can be difficult to detect and prove.
However, records show that arson was a serious problem in several southern U.S. states as early as the 1950s, when 35 to 50 percent of forest fires were believed to be arson.
Recently, a study determined Since the 1990s, about 86% of California's fires have been caused by human activity. Other studies put the number as high as 95%, of which 21% may be due to arson.
Because it takes the judicial system a long time to distinguish between accidental fires and intentional fires, It will be years before we have reliable data on whether arson has increased over the past decade.
despite this, Research shows man-made fires are more ecologically damaging than natural fires Started by lightning because they are more likely to start in open, less forested areas and on very dry and gusty days, which can increase a fire's intensity and ability to spread quickly.
Top image via ABC10/YouTube screencap
Read the Break of the Day Signal
Susan Crockford is a zoologist and evolutionary biologist at Pacific Identification Company.
