A reader kindly noted to me last month that Tamino made a slight correction to his "bet" , sometime in July. Tamino notes in his blog that "In this post I made a simple error in the statement of the bet: rather than give the equation of the lower dashed red line, I gave the equation for the trend line itself. The constant was given as 0.277455, when it should have been 0.085655. This has been corrected. The “critical value” is therefore 0.085655 + 0.018173(t-1991) , where t is the year, and for 2008 this turns out to be 0.3946."
I had noticed at the time, and noted in a response to his post, that the original equation he posted appeared to be incorrect. It appeared that instead of the equation for the upper limit for the "cooling" position Tamino had given the equation for the mid-point trend line. As a result, I calculated the lower point of the trend line and used the year mid-point in order to calculate the average value for a given year during the bet (assuming that, say, 2008 actually means the beginning of 2008 rather than the average for the year). As a result, I derived a rounded figure of .4035 degrees and have used this figure in order to monitor the status of Tamino's "bet". Because I used the year's mid-point, my figure differs slightly from Tamino's .3946 degree figure. Since it is Tamino's bet, it seems reasonable to use his definition.
With that in mind, we move to the August figures from Nasa's GISS. GISS reported a global temperature anomaly of 0.39 degrees in August. It was the coolest August of the decade; it was the fourth time this year that the global anomaly in that month represented the coolest month of the decade. For the year through August the average global temperature anomaly is now .3725 degrees or .0221 degrees below Tamino's threshold. The minimum average temperature would need to be .4388 degrees for the remainder of the year in order to meet Tamino's threshold for neither side to receive a point; below that average figure the "cooling" side would win one point.
While the issue as painted by Tamino is whether or not the earth is continuing to warm, my own opinion is that the issue is much more murky than this. I think that both are likely the case, that is, the earth is warming through human activities and the earth is presently cooling for purely natural reasons. It would be interesting to see the "cooling" side get a point this year but I suspect that the world's media would little note such an event. Why do so when one can focus on minutia like polar bears rather than the big picture?