Using the NASA data charted in a previous post, I have plotted the mean global temperature index and plotted trend lines and a 10-year moving average line.

The yellow line represents a trend created using a 2nd order polynomial (techno-geek talk for a regression with both time and time squared as variables). For convenience, the regression equation and R2 value (a measure of goodness of fit; but only one of many measures) are presented in the bottom right of the graph. Indeed, if I were Al Gore, I would be scared to death of what this means...namely that global temperatures are increasing at an increasing rate. This runaway global warming is enough to scare even the most hearty of constitution.

But a second look at the data reveals a potential problem. The red line represents a 6th order polynomial trend (a 6th order was determined to be optimal on the basis of a number of statistical criteria relating to goodness of fit). The regression equation for this line lies at the top of the graph. Notice that you get a much different interpretation from this model. Namely, global temperatures have peaked and are actually heading down!! The 10-year moving average appears to confirm this trend (note that the 10-year moving average appears to have only declined twice over the entire period when a global cooling stage was not actually beginning).

Does this analysis necessarily mean that global temperatures will continue to decline? Certainly not. But, it should give us serious pause about implementing draconian measures (I am not talking about your everyday recycling and other prudent conservation measures) that could cripple economic growth in a time of global recession.