ClimaTea Journal Club: "Contrasting responses of mean and extreme snowfall to climate change"

As we are currently witnessing, extreme snow events have a significant economic impact in mid-latitude regions! Mean seasonal snowfall has been found to decline strongly with global warming, except in regions where the temperatures are so low that all winter precipitation, even in a warmer climate, will still fall as snow. O'Gorman (2014) looks at the response of extreme daily snowfall in CMIP5 model simulations of the 21st century, and finds that the extremes of daily snowfall change much less with warming than does the seasonal mean. He develops a theory to explain this finding, with the simple reason for the result being that extreme snowfall events are most likely to occur at surface temperatures slightly below freezing, regardless of the mean monthly temperature. Thus, unlike seasonal average snowfall, extremes of daily snowfall are probably not a good indicator of regional climate change.