[therobots927]

Edit: I just realized that the chart is increase of probability between 1979 and 2020, so to modify my comment I’ll just say that it wasn’t just that geographic region that saw an increase. It seemed to correlate with the jet streams

Well the study in the link has a chart of some sort of duration weighted probability of CAT (which somehow ranges from 0 to 2.5 instead of 0 to 1?), which would correct for the total volume of flights because it’s a ratio. It’s more likely that the jet streams are getting more turbulent due to climate change.