text: This letter left me scratching my head.  What certainty am I ignoring and what "obfuscation"?  Much of Mr. Shrader's claims are patently untrue.  There is no exponential methane release in the Arctic.  There is no abrupt, runaway greenhouse gases, just a steady rise.  Mr. Schrader may not like real science with real uncertainties, but that is the way the world actually is.  He may be certain, but the scientific community knows that forecasting is essentially probabilistic...cliff mass