Speaker: Patrick Frank
Title: “No Certain Doom: On physical accuracy in projected global air temperatures”
The UN IPCC predicts that by 2100, human CO2 emissions could increase global surface air temperature by about 3 Celsius. The validity of this projection depends upon the physical accuracy of general circulation climate models (GCMs). However, model uncertainties or errors are never propagated into air temperature projections, which invariably lack physically valid error bars. This seminar will explore how GCMs project global air temperature. GCM cloud error will be described and propagated to produce a lower limit estimate of physical uncertainty in projections of future global air temperature. The extent of our knowledge of future climate will be clarified.