claim: While many scientists have acknowledged the mismatch between model predictions and actual temperature observations, few have really challenged the validity of the models themselves.
evidence: A 2007 study by David Douglass and coworkers, concluded that the 22 most commonly used global climate models used by the IPCC were unable to accurately predict accelerated warming in the troposphere although they did match actual surface warming, concluding projections of future climate based on these models should be viewed with much caution.