FIGURE 1 | Projected changes to marine heatwaves (MHWs). (A,D) Multi-model mean MHW properties from the historical runs over 1961–1990. (B,E) Change between RCP8.5 run (averaged over 2031–2060) and historical run (averaged over 1961–1990). Hatching indicates that all models agree on the sign of change (corresponding to a 1% significance level based on binomial distribution). (C,D) Annual time series for historical (black), RCP4.5 (brown), and RCP8.5 (red) runs. The gray, red and brown shaded regions show the maximum range between individual model runs. The blue shaded areas show the expected range of natural variability based on a 66% confidence interval (darkest blue), 95% confidence interval (medium blue), and full min-to-max range (lightest blue) of the historicalNat runs (1850–2005). Results for intensity are shown on the left (A,B,C) and for total MHW days on the right (D,E,F) . Equivalent figures for each individual model can be found in Supplementary Figures 2 – 7