Extreme heat and rain are now being shaped by climate change. The level to which human activity has enhanced the risk of high-impact incidents is a focus of extensive public debate. Recent studies compared climate model experiments where the influence of an external driver can be added or artificially suppressed to ascribe specific extreme events to climate change. However, several of these findings failed to account for model imperfections when forecasting the probability of severe event occurrence. Using modern weather forecasting correction techniques, we show that appropriately correcting for model probabilities changes the risk of extreme occurrences to climate change. This study demonstrates the importance of correcting for model error in order to deliver reliable judgments of Impacts of climate change.
