Sorry about the title.
My prediction of the GMT, HadCRUT (NH+SH)/2 monthly time series is now three years old. Before checking the results I would like to list some important requirements for predictions of this kind:
1) Predictions need to include prediction intervals. Predictions without prediction intervals (or such indications of confidence) are useless.
2) There has to be a reasonable mathematical or physical model behind the prediction
Note that one cannot succeed in 1 without having the requirement 2 fulfilled.
3) Prediction intervals shouldn’t be too wide. Floor to ceiling approach is too easy. The true value should pass the upper or lower limit from time to time (as the selected confidence level suggests).
4) If your prediction clearly fails, let it go. Do not move the goalposts after the fact.
Here is the result so far:
One could claim that this is a failed prediction, as there are so few values below the prediction mean. I could perform a statistical test to check it (MC runs indicate that it is ok), but I’ll do it later. Details about this prediction (requirement 2) are to be published later.
The prediction was originally presented in here ( http://climateaudit.org/2008/07/29/koutsoyiannis-et-al-2008-on-the-credibility-of-climate-predictions/ )