Hottest year on record? Not exactly - the chart shows a different story

Reports, such as one indicating 2016 to be the hottest year on record, draw on the temperature anomalies from a data set maintained by the Goddard Institute for Space Studies Surface Temperature Analysis (GISTEMP).  GISTEMP is “an estimate of global surface temperature change…using current data files from NOAA (National Oceanic and Atmospheric Administration).”  The entire 137-year monthly data set, from 1880 through June 2017, in degrees Celsius anomalies (deviations from the corresponding 1951-1980 means), as updated monthly, is located in both spreadsheet and text forms. From that data, I have generated the following chart of recent year data, particularly centered around that supposed “hottest year on record”, namely 2016. Most obvious in the chart, is that calendar year comparisons can be deceptive.  Specifically, the year 2016 (red) was NOT the hottest year on record because every month was a record, but because the first...(Read Full Post)