Did Climatologists Fake Global Warming Data?

Megan McArdle at the Atlantic asked if the global warming scientists falsified the data, "ClimateGate: Was Data Faked?"

I posted the following comment to her article:

Any number of past data points (temperatures) will successfully fit into many different models that lend themselves to different explanations of causes. What distinguishes a valid model from another is not its goodness of fit with historic data, but the goodness of fit of model predictions with actual outcomes for periods beyond the data set used.

If climatologists have a good model (and without a good model they do not have a good understanding of cause and effect for temperature changes), then the model should be able to predict future measurable temperature outcomes with an acceptable degree of accuracy beyond the time frame of the data used to develop the model.

It is my understanding that the models used and developed by global warming climatologists fail to predict accurately the global temperature outcomes for the decade just ending. That means the model is not validated. If a model is not valid for out of data time frame predictions, it is not a valid model and it offers no guidance on past causes and effects.

Too much effort is put into worrying about past data. Just ask them to predict the next decade global temperatures and watch if those results occur. Even if there are agreements in Copenhagen for massive reductions in man-made greenhouse gases, there will be enough time to see if the climatologists' predictions are accurate and to reassess the need to curb man-made green house gases.

Many of the other comments are worth reading. Some link to actual data, such as ice amounts at the polar caps and coastal sea level data, so one can judge for themselves if all the hype about global warming is true.