Evaluating IPCC Models

[AEGeneral]

I have been waiting for years for someone to start pressing this issue. What good is a climate model if it hasn't been evaluated for its accuracy as time goes on?

Climate Science: Roger Pielke Sr. Research Group News Can The IPCC Model Projections Of Global Warming Be Evaluated From Just Several Years Of Data?

Thus the value of global warming of the last 4 years fails to agree with the IPCC projections (the values are not even close!). The agrument that this is too short of a time is spurious unless the modellers can account for where else in their model results the missing Joules went.

Moreover, this is not too short of a time period to compare with the models. Heat, unlike temperature at a single level as used to construct a global average surface temperature trend, is a variable in physics that can be assessed at any time period (i.e. a snapshot) to diagnose the climate system heat content. Temperature not only has a time lag, but a single level represents an insignificant amount of mass within the climate system.



The answer to the question on this weblog “Can the IPCC model projections of global warming be evaluated from just several years of observed data” is YES. The conclusion for the past four years is that the model projections are not skillful on this time period.

I have raised this argument in various forums across the internet in recent years. The rebuttal argument against this line of thinking is that models are "long-term" projections, and any short-term variances don't necessarily disprove the model's accuracy.

In response, I've always asked when "long-term" is, and at that point, the question was dodged & the personal attacks began.

Environmentalists will defend these models to no end. Yet, all I've ever asked for is some evidence -- any evidence -- that a model can be relied upon, and I never got a straight answer.

For instance, if a model forecasts a 5-degree C increase in global temperatures by 2050, how long do we have to wait to start evaluating the model's accuracy? According to some environmentalists I've debated with, we'd have to wait decades.

Great. And meanwhile governments across the world would be passing climate change legislation of all kinds. How convenient. Perhaps that's why the IPCC chose last year to forecast sea levels for the next 1,000 years. By the time the model could be evaluated, my great-great-great-great-granddaughter would be planning her wedding.

At some point this illogical nonsense has to stop. If models can't be proven as accurate, then they shouldn't be given near the weight they presently receive. Until such time passes that actual observations can be measured against projections, these models are nothing more than educated guesses in a scientific field still in its infancy.