The 1.5-degree threshold draws closer: from March 2045 to February 2034

When the Paris Agreement was signed in December 2015, projections at the time indicated that the 1.5°C global warming threshold would be reached by March 2045. Eleven years later, the global temperature trend monitoring application of the Copernicus Climate Change Service estimates that the same threshold risks being reached by February 2034.

The analysis, published on October 29 on the eighth anniversary of the signing of the Paris Agreement, is based on data from the ERA5 dataset, the reprocessed set of observations on which the Copernicus service builds its historical temperature series.

The gap between the two dates — March 2045 in the 2015 projection, February 2034 in the current estimate — is the most direct measure of how far the pace of observed warming has diverged from the trajectories anticipated at the time the agreement was signed. This is not a date set with certainty, but a projection built on the recent trend: the Copernicus tool explicitly speaks of a risk of exceeding that date, not of an event already determined.

Supporting the plausibility of a short-term acceleration, the service points to a figure for September 2026: for the second month in a row during the year, global temperatures exceeded pre-industrial levels by more than 1.5°C, placing the month second among the warmest Septembers ever recorded.

The comparison between the two projections — that of 2015 and that of 2026 — thus remains the central element of this analysis: eleven years of difference between the date expected at the time the Paris Agreement was signed and the one calculated today based on the trend observed through September 2026.