procrastination and paleoclimate

It's lightly snowing, a flock of redpolls are at the feeder, my amaryllis bloomed, and I'm procrastinating.  Jon headed to Valdez for the weekend, to be followed up by Chickaloon adventures early next week.  I  couldn't go because I have way too much work to do, but somehow I find the time to sit around for two hours this morning drinking coffee and listening to NPR.  I'll regret this later...

I may have work this summer helping FWS with a dendrochronology project (that's the fancy word for a tree-ring study).  So I was thinking about this when NPR played a piece on California's current drought, which got me thinking about past North American climates (paleoclimates).  

We have instrumental records for about the last 100 years, but people can use all sorts of data to piece together what even earlier climates were like.  Tree rings are one of those things - rings are thinner during a drought, as the tree just doesn't have enough water to grow very much.  In the eastern U.S., researchers have used baldcypress trees to reconstruct the climate going back to 1185.  wow!  one of the two the biggest droughts in this 800 year period was around 1587, when the Roanoke colonists disappeared. 

Bristlecone pines in the Methuselah grove look even further back.  One tree was nearly 5,000 years old when cut down in 1964!  (how bad must that logger feel, taking out the world's oldest tree?)  Records from these trees and other techniques show that western North America has had some pretty wicked droughts.  Seriously bad, put the dustbowl and Roanoke colony droughts to shame bad.  This study looked back nearly 8,000 years and found 8 multi-decadal droughts, the most recent were in 924 and 1299 AD.  

There a neat paper I read for a course last year that talks about drought records and cultural responses (deMenocal 2001 Cultural Responses to Climate Change During the Late Holocene Science Magazine vol 292  www.sciencemag.org).  Basically positing climate - these long term droughts  - was a major factor in the disappearance of some historical cultures.  For example, he points out that the 1299 "mega-drought" coincided with abandonment of Anasazi settlements. 

Definitely makes me think about water resources in the west.  Paleoclimate work shows that these large, long-term droughts do occur in North America,so we can reasonably expect one to occur again (though who knows when - in 10 years, 100 years, 1000 years...?).  How would we, as a nation, have to adapt?   It sure wouldn't be pretty...

NOAA has a really nice site talking about drought and paleoclimate (Drought - A Paleo Perspective).  I definitely recommend poking around there, they do a great job of explaining things for the average joe.

OK, now back to work...