The Blackboard

One of the on going blog-disputes related to testing the IPCC AR4 projections of the Global Mean Surface Temperature (GMST) is whether one should the variability of 8 year trends for earth weather based on observation of the earth’s weather or based on the variability of model trends.
Of course, if the statistical properties “model weather [...]

As I previously mentioned, I’m just looking at global mean surface temperature “model-data” from the GCM’s that form the basis for the predictions/projections in the AR4. As we often read, each model has its strengths, each has its weaknesses, but somehow the average is “best”.
So, I can’t help wondering if the [...]

Recently, I’ve been downloading “model data” from GCM runs that form the basis for projections in the IPCC AR4. I’m planning to compare some of the features to see how well the models reproduce the statistical properties of “weather noise”. But, first, I’m just plotting and looking at observations of earth data. [...]

Does the IPCC describe uncertainties in a quantitative way that is accessible to readers? I expressed my opinion in comments: the IPCC generally resorts to qualitative discussions, and in particular, they become quite qualitative when discussing individual models.
I think this vagueness is unfortunate as it results in various people arguing about [...]