By all accounts, 2011 has been a year of extreme weather across the U.S. Severe flooding in New England, a catastrophic drought across the Southern Plains, the worst tornado outbreak in recorded history, massive haboobs in the West and destructive wildfires across Texas have all dominated the headlines.
While years like this spawn doomsday discussions about the viability of our ecosystems, the threat to agriculture and the future welfare of mankind, they have no true predictive value. Though a backdrop of global warming cannot be ignored, these outbreaks of severe weather are more directly related to stagnant weather patterns, atmospheric derangements that often produce adjacent extremes of heat and cold, deluge and drought etc. A warmer climate may add fuel to the fire but the events themselves are sporadic; the last comparable episode of tornadic activity was in 1974 (almost 40 years ago) and the disastrous hurricane season of 2005 has since been followed by rather tepid years for tropical storms in the Atlantic Basin.
Periods of extreme weather always grab our attention and, since we are still rebounding from a glacial epoch, they are likely to be more intense when they do occur. But our relatively brief history of recorded weather gives us the impression that these outbreaks are both more extreme and less common than they actually have been from the broader perspective of Earth's history. Rather, we are now here to observe, document and be threatened by natural events that molded this planet long before our species evolved (or had the capability to record them).
