Extended Data Fig. 2: Reliability of calibrated climate model predictions.
From: Twelve months at 1.5 °C signals earlier than expected breach of Paris Agreement threshold
Histograms of probability integral transform (PIT) values for calibrated CMIP6 predictions of the difference in time between short- and long-term exceedance of known global temperature anomaly thresholds in ERA5 (35 samples). A reliable, well-calibrated ensemble should exhibit a uniform PIT distribution. A U shape indicates that predictions are underdispersive, while a dome shape indicates that predictions are overdispersive. Excess probability density for low PIT values means that predictions are biased; in this case, they are higher than observed too frequently.
