Since they seem to have data all the way back to 1880 why do you think they did not use the 1880-2015 annual average? It seems that they could have computed that average and used it. The only reason I can think of is that they wanted their baseline to be as precise as possible and with the advances in global sensing it is clear that the annual average for 1980 to 2015 would be much more precise because of more accurate measurements and more data points.Kim OHara wrote:Poorly labelled rather than mislabelled, Ron. The text isn't the title of the graph (although it looks like it is) but the label on the vertical scale.Ron-The-Elder wrote:Hi, Rowboat:
Thanks for the graph. However, it is mislabeled. Should read: "from Jan 1880 to Jul 2016.
What it is saying is that the scale is the "Temperature Anomaly, i.e. the difference from the 1980-2015 annual average," i.e., zero on that scale is the annual mean global temperature.