Climate models?

Question

Do the climate models used by the IPCC predict the Little Ice Age and the Medieval Climate Optimum?

Answer 1

I can not definitively state that it does, however any model utilized must be able to reconcile the past with the present before it can be stated to effectively predict the future.

A credibility test for models is their ability to simulate past climatic periods, e.g. Cretaceous and the Last Glacial Maximum which represent abnormally warm and cold climates respectively. Models are also run to simulate the effects of recent volcanic eruptions to test atmospheric chemistry circulation interactions. Volcanic eruptions are a significant factor in current and past climate variability. Climate Model Projection (Figure 4)

Answer 2

Important Note:
The IPCC is a policy adviser, not a scientific panel. It relies on scientific institutions to produce the models and collect the data that it uses in its reports. (The Hadley Center is the leader in climate modeling if you were wondering.)

That said, the IPCC uses a number of different models in their reports. Most can predict the Little Ice Age, and some can predict the medieval warm period.

Though you need to remember that there were no reliable measurements for temperatures in the middle ages, so there is still much debate about whether or not there actually was a warm period.