Quick hit on the impact of the May HadCrut anomaly
Posted by The Diatribe Guy on June 29, 2011
Now that I have everything updated for April month-end, I just checked the HadCrut data set and see that they have released the May anomaly of 0.322.
This is actually a slightly lower value than the 12-month average value I had been using for my comments on the impact of future trend lines.
As I was reviewing, I am embarrassed once again to note an error that I uncovered in the process: that my 60-month chart was actually a 50-month chart. When corrected, the current slope on the 60-month chart is actually only 0.0167 at paril month end (nearly flat). This value was properly reflected on the slope charts, but not on the raw data chart. I will edit the post(s) as appropriate to reference that.
Anyway, I am not going to update all the charts, but thought I’d plunk in the new anomaly (caveat: I did not refresh the entire data set, and this will not account for any historical adjustments to the data). Here are the results:
60-month trend line has gone negative: slope = -0.009517. Expect a larger drop in this over the next two months. Equivalent of 0.006 degrees of total cooling over that period.
120-month trend line: Went more deeply negative. Slope = -0.064081. Equates to 0.077 degrees cooling over the last ten years.
180-month trend line: Slope dropped to 0.049704, the equivalent of 0.089 degrees warming over the entire period.
240-month trend line: Slope dropped to 0.138774, the equivalent of 0.333 degrees warming over that 20-year period.
300-month trend line: Slope dropped to 0.129338, the equivalent of 0.388 degrees warming over that 25 year period.
360-month trend line: Slope dropped to 0.134971, the equivalent of 0.486 degrees warming over that 30 year period.
With the new anomaly, the current longest trend line back that demonstrates a negative slope is still 14 years (June 1997 – May 2011).