Are climate models biased?

If you took an average output of multiple climate models, it would predict that the start of this century would have seen a strong warming trend. Instead, the planet warmed relatively slowly over this time.

When models and reality disagree, it can tell us about two things: the models and reality. So far, analysis has seemed to come down on the side of reality. Evidence has indicated that one of the contributors to this century's climate has been small volcanic eruptions; another suggests that a run of La Niña years has helped hold temperatures down.

Now, a new study is out that turns the focus on the models. It finds no evidence that the models are biased toward predicting higher temperatures and instead suggests that their biggest issue might be in how they handle large volcanic eruptions.