CMIP5 Climate model predictions for the coming decades is an integral part of the upcoming IPCC assessment.
The CMIP5 - Coupled Model Intercomparison Project Phase 5 is intended to
“to promote a new set of coordinated climate model experiments. These experiments comprise the fifth phase of the Coupled Model Intercomparison Project (CMIP5). CMIP5 will notably provide a multi-model context for 1) assessing the mechanisms responsible for model differences in poorly understood feedbacks associated with the carbon cycle and with clouds, 2) examining climate “predictability” and exploring the ability of models to predict climate on decadal time scales, and, more generally, 3) determining why similarly forced models produce a range of responses.”
They report that
CMIP5 promotes a standard set of model simulations in order to:
- evaluate how realistic the models are in simulating the recent past,
- provide projections of future climate change on two time scales, near term (out to about 2035) and long term (out to 2100 and beyond), and
- understand some of the factors responsible for differences in model projections, including quantifying some key feedbacks such as those involving clouds and the carbon cycle
My post today is to summarize the lack of scientific value in those model predictions with respect to “evaluate how realistic the models are in simulating the recent past” and, thus their use to project (predict) “future climate change on two time scales, near term (out to about 2035) and long term (out to 2100 and beyond.” My post brings together information from several recent posts.


