Chart: Annual global surface temperature anomaly relative to a 1880-1909 baseline

Andy Skuce, Critical Angle

Andy Skuce adapts the NASA GISTEMP global annual surface temperature anomaly data (which uses a 1951-1980 baseline) to a 1880-1909 baseline, which is a closer match to the “pre-industrial” datum used as the basis for UNFCCC temperature targets. The above graph is how this looks, with the addition of a 42-point LOESS regression smoother.

The trend is now above the 1.0°C anomaly level relative to pre-industrial temperatures. The smoothed line shows remarkable linearity since 1980. Simply extending this trend to 2050, as shown by the dotted line, suggests that the 1.5°C threshold will be reached in about 25 years. We are now already halfway to  2.0°C and two-thirds of the way to  1.5°C.