If they are aligned in the modern period (when the differences between the methods/data are minimal), there is clearly a variation in both inferred interannual variability and mean change in the ‘pre-industrial’ period (see fig. Adding an offset so that the WMO average was zero over the baseline takes you back to 1.54ºC. Baselined so that the average of the four longest records are zero over the 1850-1900 ‘pre-industrial’ period. On a monthly basis we have been exceeding 1.5ºC in the individual records (briefly) since the El Niño event of 2016 (maybe 2017 and 2019, and then again in 2020). Monthly anomalies from 2010 with a modern baseline and offset to have a zero average over 1850-1900.

Source: New York Times December 29, 2025 20:34 UTC