Over many years there have been discussions, and also disagreement, about how well climate models can predict the future climate. The IPCC asserts that climate models are based on established physical laws along with a wealth of observations, so the models must be very good representations of nature. A prominent climate scientist and energy analyst asserts that climate models do remarkably well, and that most of the projections are statistically indistinguishable from observations. However, an analysis of the model ensemble used in the Climate Model Intercomparison Project 6 (CMIP6), shows a very wide spread of individual projections. Moreover, the hindcasts also vary greatly even if the full temperature history is known. So, what does the models say about the warming since “pre-industrial times”? There is almost a four-fold variation in results, with warming from 0.6 °C to almost four times that, 2.3 °C.
