Thursday, January 30, 2014

Why the Current Drought Isn't Caused by "Global Warming"

Today's headline:

Las Vegas – January 30, 2014 – Four leading climate change researchers from states experiencing emergency-level drought argued that the drought is clearly linked to climate change, with its current effects and future outlook made worse by persistent higher temperatures due to a warming climate.

-- one of a number of stories today about the drought in the West.

There has been a lot of nonsense lately about how "the drought in the West" is being "caused" by global warming/climate change/global weirding, etc. At this point, there is no reason to bring global warming into the discussion.

#1. There is usually a drought in the central or western U.S. in the odd-numbers decades. I've researched this back into the 1880's. Here are are examples of the Palmer Drought Index.






Look at the dates. See a pattern? In fact, if you ask a Kansan over about the age of 40 they will tell you about the "twenty-year drought cycle." If there wasn't a drought in an odd-numbered decade, that would be evidence of climate change! A number of climatologists believe this is related to the 22-year sunspot cycle but there is no consensus on that issue.

#2. So, let's look at the current drought that has the media so excited. Since these are monthly maps, December is the most recent. It has gotten incrementally worse during January.
Since the above map was posted, part of central California was upgraded this week to an "exceptional" drought (dark patch on map below).
Regardless of its size, for the local residents, this very serious. Drinking water is in jeopardy.

That said, so far, this drought is small in size. This drought, as droughts go, is neither unusual nor historic. 

The forecast in California the next five days is for some light to moderate moisture. It is enough to keep the drought from getting worse, but will do little or nothing to improve the situation.
Will the drought continue? Short term, very likely. Unfortunately, our tools are not reliable enough to make a forecast beyond a few weeks. Because this is California's "rainy season" (until April), the rains would need to kick in soon or another 8-9 months of drought would be "baked in" until next year's seasonal rains (hopefully) kick in.

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