Pyromania is defined as a pattern of deliberate setting of fires for pleasure or satisfaction derived from the relief of tension experienced before the fire-setting. The name of the disorder comes from two Greek words that mean "fire" and "loss of reason" or "madness." The clinician's handbook, the Diagnostic and Statistical Manual of Mental Disorders , also known as the DSM, classifies pyromania as a disorder of impulse control, meaning that a person diagnosed with pyromania fails to resist the impulsive desire to set fires—as opposed to the organized planning of an arsonist or terrorist.
Scientists have been warning for decades that climate change is a threat to the immense tracts of forest that ring the Northern Hemisphere, with rising temperatures, drying trees and earlier melting of snow contributing to a growing number of wildfires.
The near-destruction of a Canadian city last week by a fire that sent almost 90,000 people fleeing for their lives is grim proof that the threat to these vast stands of spruce and other resinous trees, collectively known as the boreal forest, is real. And scientists say a large-scale loss of the forest could have profound consequences for efforts to limit the damage from climate change.
In retrospect, it is clear that Fort McMurray, in northern Alberta, was particularly vulnerable as one of the largest human outposts in the boreal forest. But the destruction of patches of this forest by fire, as well as invasions by insects surviving warmer winters, has occurred throughout the hemisphere.
In Russia, about 70 million acres burned in 2012, new statistics suggest, much of that in isolated areas of Siberia. Alaska, home to most of the boreal forest in the United States, had its second-largest fire season on record in 2015, with 768 fires burning more than five million acres.
Global warming is suspected as a prime culprit in the rise of these fires. The warming is hitting northern regions especially hard: Temperatures are climbing faster there than for the Earth as a whole, snow cover is melting prematurely, and forests are drying out earlier than in the past. The excess heat may even be causing an increase in lightning, which often sets off the most devastating wildfires.