In blue, the source of the original anomalies is the combined UK Met Office Hadley Centre and Climate Research Unit dataset, HadCRUT3. The global mean annual temperature deviations are in relation to the base period 1961-1990. In red, the source of the original anomalies is NASA's GISS dataset. The anomalies are in the source in relation to the base period 1951-1980. The global mean annual temperature deviations have been adjusted to be relative to the period 1850-1899 (HadCRUT3) and 1880 - 1899 (NASA's GISS). All original data is rounded to the nearest 2 decimal places. The trend lines show the 10-year centred moving average of the original anomalies for both datasets relative to the period 1880-1899. The dotted lines show the annual anomalies of the HadCRUT3 (blue) data set and GISS (red) respectively.