The [FCC fth assessment report notes that there is a nonnegligible chance of S being greater than 7.5 degrees but didn't go into detail about probabilities. In the paper \"Fat-Tailed Uncertainty in the Economics of Catastrophic Climate Change\" Martin Weitzman discusses how different models for the PDF of Climate Sensitivity (S) for large values of S have wildly different policy implications. For values of S greater than 7.5 degrees Celsius, we are going to model S as a continuous random variable. Consider two different assumptions for S when it is greater than 7.5: a fat tailed distribution ()9) and a thin tailed distribution ()3): K K f1(a:) = E 8.1:. 7.5