The latest monthly highs suggest that the 1.5°C Paris Agreement threshold will probably be exceeded before 2028

Abstract

An attempt is made to estimate and forecast the trend of the global annual and monthly mean temperatures. The results of a conventional statistical analysis suggest that in the absence of unforeseeable events such as a sudden acceleration in the rate of warming, the 1.5°C Paris Agreement threshold could be exceeded between 2027 and 2031. However, carrying out a proper seasonal adjustment and examining the autocorrelation structure carefully, we find in a subsequent purely statistical simulation study that even the pessimistic scenario of a breach in late 2027 is inconsistent with the recent monthly highs, which means that it will probably happen much sooner.

14 pages, 10 figures