As I have noted previously, Tamino has made a "bet" that global temperatures would continue to increase between now and 2015 in line with the 1975 to 2007 trend. The conditions of the bet for the year 2008 are as follows:
1. If the average global temperature anomaly, as measured by NASA GISS, equals or exceeds .7350 degrees Celsius, the "still-warming" side will receive one point.
2. If the average global temperature anomaly, as measured by NASA GISS, is less than or equal to .4035 degrees Celsius, the "not-warming" side will receive one point.
3. If the average global temperature anomaly, as measured by NASA GISS, falls between these two figures, both sides will receive zero points in 2008.
The March figures reveal a dramatic increase in the global temperature anomaly from the previous month. The NASA GISS figures for March showed a global anomaly of .67 degrees for March, an increase of .41 degrees Celsius between February and March. The figure for March raises the average NASA GISS global temperature anomaly thus far for 2008 to .35 degrees Celsius. In order for the "not-warming" side to win a point in 2008, the average anomaly for the reminder of the year would need to be below .4213 degrees. As I noted last month, since the average anomaly for a 9-month period has exceeded this figure for every month since September 2001, it would still seem unlikely that the "not-warming" side will win the point in 2008.
I also want to note that the month-to-month increase in the NASA GISS anomaly represented the 3rd greatest month-to-month increase in the 128-year time series. Since I have noted that the recent declines in temperature were unprecedented, it is only fair to note that the February to March increase was nearly equally dramatic. While some unreferenced but readily available off-the-wall commentary among some climate "skeptics" has suggested that this increase represents some kind of conspiracy, I personally think this increase does reflect that some level of human-induced warming is in fact present. However, I also believe that a significant proportion of the increase in global temperatures between 1975 and 2006 was due to natural causes and that we are likely to see short to mid-term reductions in global temperatures regardless of the background effect of human-induced warming as a result of a reversal in this trend.
I believe we are therefore at a turning point of some kind in the debate between the "still warming" and "not warming" camps. Should global tempertures return to levels seen before the recent "La Nina" episode and resume their upward climb, it would not be unreasonable to suppose that the "still warming" camp may be correct. However, should global temperatures stabilize at some lower level than what was seen before the recent "La Nina" episode, then the issue may very well be in the balance. The results from the upcoming 12 to 24 months may well represent some kind of turning point in this debate.