I highly recommend reading the post by Roy Spencer titled

Deep Ocean Temperature Change Spaghetti: 15 Climate Models Versus Observations

Roy discusses his comparison between the 20th Century runs from most (15) of the IPCC AR4 climate models, and Levitus observations of ocean warming during 1955-1999,

This is a very important study [which I urge him to submit soon for publication] because:

1. It uses ocean heat storage change as the metric to diagnose global warming (or cooling). The value in doing this, in contrast to using the global average surface temperature trend, is presented, for example, in

Pielke Sr., R.A., 2003: Heat storage within the Earth system. Bull. Amer. Meteor. Soc., 84, 331-335

and

Pielke Sr., R.A., 2008: A broader view of the role of humans in the climate system. Physics Today, 61, Vol. 11, 54-55.

2. The study uses real world observations to compare with the model results, in contrast to model to model comparisons.

Roy should be commended for tackling a very important climate science issue in this robust manner. Other climate scientists are welcome to present guest posts on my weblog, if they conclude his analysis is flawed.

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