The historic Texas fires associated with the severe 12-month drought of 2011 were the subject of the weekly science column that I write for two Texas newspapers and which are sometimes posted on this blog.Â So I was surprised that the March 22, 2012, PBS News Hour report on the Texas drought failed to mention that the catastrophic drought of 2011 was not unprecedented.
Climate change has always occurred, and the droughts it can bring are nicely preserved in the annual growth rings of certain trees, especially the baldcypress of Mexico (Taxodium mucronatum). These natural records reveal occasional megadroughts that lasted decades and would be far more devastating to Texas today than the 2011 drought. Megadroughts are mentioned in â€œThe Impact of the 2011 Drought and Beyondâ€ and in a number of scholarly papers.
As for the temperature of Texas, regular records were begun in 1895. A linear fit to the data available from NOAA show that the average annual temperature of the State increased a statistically insignificant 0.046 degree from 1895 to 2011, which includes last year's drought. The temperature data are freely availableÂ here.
The blue line indicates the average annual temperature of Texas from 1895 to 2011. The red line is a linear regression of the data that indicates an increase of only 0.046 degree F in 116 years.