Story submitted by Forrest Mims III, originally published for the San Antonio Express-News
In the early days of this column, concerned readers sent many questions about the earth’s ozone layer, which I began measuring in 1990. Today, public interest in the ozone layer has been replaced by concern about global warming.
Answering questions about global warming requires considerably more space than this 437-word column. So let’s focus in on the temperature history of Texas for now.
The 2011 Texas drought was exacerbated by the highest temperatures since 1895 during June, July and August. Several prominent climate scientists have blamed these record highs on global warming. These claims are puzzling because, in spite of the 2011 record highs, Texas records going back more than a century show slightly more cooling than warming. So I visited the National Climatic Data Center website to review Texas temperature records. The NCDC provides monthly temperature records for 10 Texas regions going back to 1895.
It also provides the average temperature for the entire state.
I retrieved all 12 months of data for each year since 1895 and plotted the average annual temperatures on a chart along with their trend. As shown in the chart, the average temperature of Texas barely changed between 1895 and 2011.
The total warming during those 116 years was a statistically insignificant 0.046 degree Fahrenheit. If the record highs of 2011 are omitted, Texas cooled 0.055 degree from 1895 to 2010.
The NCDC temperature data do not fully account for the enhanced warming of weather stations that have become surrounded by buildings and pavement. This is the heat island effect. Dr. Daniel Boice of the Southwest Research Foundation studied the temperature at New Braunfels and San Antonio from 1946 to 1990. www.swri.org/3pubs/ttoday/fall97/heat.htm
He found that San Antonio has warmed when compared with its smaller neighbor. San Antonio might be several degrees cooler today than in 1885 if no new buildings and roads had been constructed. Why do some scientists insist that Texas is warming when the data show a negligible increase? I don’t know. But I do know that a National Science Foundation program officer told me that applications for atmospheric science grants that do not include a global warming theme stand little chance of acceptance.
Climate scientists are right to be concerned about droughts, especially since no Texas drought since precipitation records were begun around 1870 matches the megadroughts revealed in the rings of bald cypress trees. Those droughts occurred hundreds of years before SUVs and power plants began pumping carbon dioxide into the atmosphere, a process blamed for global warming that has not yet arrived in Texas.
Forrest Mims III, an expert reviewer for the Intergovernmental Panel on Climate Change, was named one of the 50 Best Brains in Science by Discover Magazine. His science is featured at www.forrestmims.org. Email him at firstname.lastname@example.org.