The role of urban areas within the climate system is yet another human climate effect whose role was minimized in the 2007 IPCC WG1 Report. - Roger A. Pielke

Climate forecasts (projections) decades into the future have not demonstrated skill in forecasting local, regional, and global climate variables.

Humans are significantly altering the global climate, but in a variety of diverse ways beyond the radiative effect of carbon dioxide. The IPCC assessments have been too conservative in recognizing the importance of these human climate forcings as they alter regional and global climate. These assessments have also not communicated the inability of the models to accurately forecast the spread of possibilities of future climate. The forecasts, therefore, do not provide any skill in quantifying the impact of different mitigation strategies on the actual climate response that would occur.

The claim by the IPCC that an imposed climate forcing (such as added atmospheric concentrations of CO2) can work through the parameterizations involved in the atmospheric, land, ocean and continental ice sheet components of the climate model to create skillful global and regional forecasts decades from now is a remarkable statement. That the IPCC states that this is a ‘much more easily solved problem than forecasting weather patterns just weeks from now’ is clearly a ridiculous scientific claim.