Philip wrote:Questioner wrote:... Hansen's 1988 paper ... says specifically that he starts his simulations with actual climatological conditions for the year 1958. This is not some constructed equilibrium condition.
I think you are misremembering what this paper actually says. Here is a snippet:Section 6.4 Initial Conditions
By initiating our experiments in 1958 after a long control run with 1958 atmospheric composition, we implicitly assume that the ocean temperature was approximately in equilibrium with the initial atmospheric composition. Our results could be significantly modified by a different assumption.
It is true that it is better to start a model run from a state of equilibrium between ocean and radiation, because the state of the ocean can be specified more accurately that way. If accurate non equilibrium conditions could be established by measurement, the models would work just as well, because they do handle transient conditions.
Further down Hansen explains that the historical temperature record does seem to confirm that the assumption of equilibrium of ocean and atmosphere was correct. Remember that Hansen didn't have the most powerful computers available at the time. He used a 1975 Amdahl computer when he did his work in the mid 1980's. He actually made only one run for each scenario, using only one set of initial conditions. He chose the initial conditions quite well given the results that he got. With a more powerful computer he probably would have run a variety of initial conditions for each scenario.
In addition, he seems to have been prescient in his estimate that one volcanic eruption of the magnitude similar to Agung, would occur in the 1990's, and ran his scenarios with that assumptions. Indeed we had Pinatubo.Even without this explicit statement from Hansen et al, if you think about your assertion for a moment, you will find it is simply not tenable. The "actual climatological conditions for the year 1958" are simply not known. In truth, it is almost inconceivable that a reductionist computer simulation would be able to take due account of the effect of long-term climate variations.
It is inconceivable to you because you don't like to accept the idea that predictions of global warming can be made.
What is pretty clear to me is that Hansen was recognized as a pioneering genius in his time, and given grant money and authority to direct research long before global warming became a real concern. He is certainly smarter than you or me, and the number of honors and awards he has won is evidence of this. The deniers who scoff at him are not fit to lick his boots.I also note (with some amusement) that even in 1988 this author was already talking of his computer simulations as "experiments". Another joke perhaps?
Hardly a joke. Simulation is the only way we can "experiment" with the future to look at the effects of different courses of action.Questioner wrote:What predictions do you call unphysical?Philip wrote:Very high temperature rises.Questioner wrote:Your reasons are mere surmise, and not rigorous.Philip wrote:My argument is based on simple mathematics and physics...Questioner wrote:It is your argument that has no reason on its side. You have absolutely no evidence to support it except your opinion.Philip wrote:On the contrary, my argument is based on well-established and uncontroversial physics, physics that is even mentioned by the IPCC in AR4.Questioner wrote:You can't expect to have an intelligent discussion if you won't be more specific about this. I am not a mind reader.
For the specifics please refer to the thread I cited earlier, viewtopic.php?f=5&t=479.
I couldn't find where you made an argument based on well established and non controversial physics. At least provide a pointer to a specific post that and the page in the particular IPCC AR4 where your argument appears.