Friday, April 8, 2011

Al Gored by the Data

I seldom stray from writing of wrongful convictions and executions. My skepticism, however, is not restricted to the accuracy of our justice system. Given my engineering background, my skeptical klaxon sounds frequently as those who are out to serve us pontificate on issues ranging from financial solvency to alternative energy. I usually withhold comment. This post is therefore unusual.

AccuWeather has posted an article: "Coolest March Since 1994." (How can you not trust something from a source with "Accu" in its name?) Based on satellite temperature readings, March turned out to be relatively cool. The fine folks at AccuWeather even put a chart at the bottom of their article. Unfortunately, they failed to label the axes. I presume we're supposed to notice the trend line is still sloping upward and we're supposed to conclude that we are still doomed to melt, assuming we don't first drown or return to our pre-industrial ways.

The article did, however, link to the data used to construct the plot. I commend the fine folks at AccuWeather for that. (Seriously, I commend them for that.) I refer you to their article if you would like to manipulate the data yourself. I have used the data to create two plots which I present below. Click on either to have the pair appear enlarged in a separate window.

The upper plot is a reproduction of the plot provided in the AccuWeather article. Mine differs only in that I cluttered them by labeling the axes. Oh, yeah. I also colored the data a scary red to indicate things are getting hotter and hotter.

In the lower plot, I split the data roughly in half. It seemed to me that something significant happened near the beginning of 1998. As before, the first half of the data shows the temperature to be increasing, though the increase is not as steep as in the upper plot. I colored it scary red anyway.

The second half of the data represents the global temperature trend for the last twelve years. This may come as a shock to you, but we have not had any global warming for the last twelve years. In fact, according to the U.S. NOAA Climate and Global Change Program, it has been cooling slightly. I therefore colored those data in a comforting, earth-friendly green.

I don't know what the temperature will be next month, next year, next decade, or next century. Some people claim to know, and those people want to make energy more expensive and want to further restrict our liberty.

I thought you would be pleased to know that no longer appears necessary.

You're welcome.