© Getty ImagesFull water levels are visible behind the Folsom Dam at Folsom Lake on July 20, 2011, in Folsom, Calif. Low water levels are shown on Aug. 19 in Folsom, Calif.
Megadroughts are extreme dry spells that can last for a decade or longer. They have parched the West, including present-day California, long before Europeans settled the region in the 1800sCalifornia is in the third year of one of the state's worst droughts in the past century, one that's led to fierce wildfires, water shortages and restrictions, and potentially staggering agricultural losses.
The dryness in California is only part of a longer-term, 15-year drought across most of the Western USA, one that bioclimatologist Park Williams said is notable because "more area in the West has persistently been in drought during the past 15 years than in any other 15-year period since the 1150s and 1160s" - that's more than 850 years ago.
"When considering the West as a whole, we are currently in the midst of a historically relevant megadrought," said Williams, a professor at the Lamont-Doherty Earth Observatory of Columbia University in New York.
Megadroughts are what Cornell University scientist Toby Ault calls the "great white sharks of climate: powerful, dangerous and hard to detect before it's too late. They have happened in the past, and they are still out there, lurking in what is possible for the future, even without climate change." Ault goes so far as to call megadroughts "a threat to civilization."
What Is A Megadrought?Megadroughts are defined more by their duration than their severity. They are extreme dry spells that can last for a decade or longer, according to research meteorologist Martin Hoerling of the National Oceanic and Atmospheric Administration.
Megadroughts have parched the West, including present-day California, long before Europeans settled the region in the 1800s.
Comment: In sum, 2013 saw fewer disasters, deaths, victims and economic damages on the whole. However, it saw isolated instances of record-breaking disasters, while floods and storms were responsible for the worst damage in terms of people affected. China and the U.S. continue to be hit the hardest, with China enduring its highest number of disasters in the last decade.
As Pierre Lescaudron describes in his book, Earth Changes and the Human-Cosmic Connection, this apparent decrease in disasters is probably due to an overall decrease in the Earth's electric field (due to a solar-companion-induced drop in the Sun's activity) and an increase in the conductivity of that field (due to the increase in comet dust entering our atmosphere). The result: more frequent, smaller storms (hurricanes, tornadoes, lightning, etc.). This will show up in the statistics as a drop in major natural disasters, but as we can see around us, it doesn't say much about the continued crazy weather the planet has been experiencing the last couple years.
It's the time for floods and storms to do their damage, while cosmically-induced processes perhaps build up for some future, major disasters. Think Chelyabinsk. Think Ebola.