“In 2015 our projected deadline for reaching 1.5°C was 27 years away. Now, the application estimates the threshold is only 4 years away, suggesting global warming has accelerated quickly in recent years.
It is important to note this is based on a linear extrapolation, which cannot distinguish between acceleration due to increased greenhouse gases and natural climate variability. Nevertheless, this basic projection offers a clear estimate of the rapid pace of warming”
https://climate.copernicus.eu/rapid-approach-15degc-global-warming-threshold-paris-agreement