I have long contended that the current discussions of global temperatures are ill served by the attempts to apply a regional concept to the entire globe. A new language is needed to describe the concepts under study.
One drawback of using the concept of global climate is that the monthly and annual figures for modelled global temperature are passed off as representing climate, rather than just a summary of global weather. The scientific, as opposed to the headline grabbing alarmist, approach must surely be to use the 30 year average ie ‘climate‘ rather than the monthly/annual ie ‘weather‘.
How does this affect HADCRUT 4?
The graph shows the 30 year averages, plus the decadal trends in these values.
The slow natural change in temperature can clearly be seen, as the cyclical nature of the changes, all under the control of natural variability.
Frayedends Blog 