The probability of the first year at or above a warming level falling within the 20-year period reaching the same level, derived from an idealized experiment for different trends (y axis) and standard deviations (x axis) of the temperature time series. Blue-filled symbols show trends and standard deviations from observational datasets during the 20-year warming level period (colours as in Fig. 1a). Red-filled symbols denote probabilities from climate models, plotted against the multimodel median of trends and standard deviations (note, the symbols for 0.5 C in SSP1-2.6 and SSP2-4.5 overlap).
