Is the West’s Dry Spell Really a Megadrought?
The drought that has been afflicting most of the Western states for the past 13 years may be a “megadrought,” and the likelihood is high that this century could see a multi-decade dry spell like nothing else seen over the past 1,000 years, according to research presented at the American Geophysical Union Fall Meeting on Wednesday and Thursday.
Today, drought or abnormally dry conditions are affecting every state west of the Mississippi River and many on the East Coast, with much of the Southwest under long-term severe, extreme or exceptional drought conditions. While drought conditions nationwide are down this year, they remain entrenched in the West.
Is the West’s Dry Spell Really a Megadrought?
The cool phase of the Pacific Decadal Oscillation (PDO) enables stronger high pressure systems in the Pacific that block moisture laden winds from reach the American Southwest. The PDO's 20 to 30 year cycles correlate well with past megadroughts.
ReplyDeleteToo much hype has been given to CO2 caused climate change models which suggest future droughts will be caused by warmer summers. In contrast these recent droughts, and past megadroughts are initiated by drier winters.
To build a more resiiient environment, we should direct funding and research towards watershed restoration in order to hold the water on the land as long as possible. The current degradation of our streams and lost wetlands, as well as urbanization effects that try to run the water off the land as quickly as possible, dries the soils and reduces the soils heat capacity further, exacerbating droughts and heat waves. The climate change debate has caused us to lose sight of these natural cycles of drought. Instead of misdirecting funds to create speculative scenarios about possible effects of rising CO2, we need to redirect funding towards restoring watersheds and better prediction to prepared for natural cycles! Controlling our CO2 will never stop these natural megadroughts.