Evaluating Working Group (WG) II’s Contribution to the IPCC’s Fourth Assessment Report (AR4) reviews and critiques the findings contained in the Summary for Policymakers (SPM) of Working Group (WG) II’s contribution to the Intergovernmental Panel on Climate Change (IPCC)’s Fourth Assessment Report (AR4) that are likely to attract the most attention.
In reviewing the methodology used to generate the alarming conclusions of Working Group II, we concluded that “Each of these steps is so fraught with uncertainty or unrealistic assumptions that the outputs of the exercise are meaningless.”
The piece reviews these concerns with methodology and also specifically examines conclusions about adaptation, extreme weather, species extinction, and disease among others. Unfortunately, the SPM presents only the direst view of the future. The piece notes: “By presenting only the worst case, WG II paints an overly negative and unrealistic view of the future. Policymakers need to know a possible worst case, but they also need to understand the more likely outcomes. WG II does not provide this information.”