David Roberson <[email protected]> wrote:
> You seem to be a guy that likes to think through issues that are of > importance as well. Perhaps you might want to consider the complexity of > the global warming models for a moment. Do you honestly believe that the > software guys have included all of the variables that influence the future > climate in their models? With such a complex system, I doubt it is possible to include all the variables, even in principle. You cannot be sure you have discovered them all. You can only model the recent past and see if your computer correctly predicts things such as the weather yesterday, or climate change over the last 30 years. It can only be an approximation. That is how natural science works. > All you need to do is to realize that there are several different models > that are consulted as these scientists predict the future. Why several? > If each one is suspect, then one would expect that the average prediction > is also suspect. > I would not say that. I do not know the details in this case. In biology, medicine and other natural sciences there are often different levels at which you can model something. You can look at evolution from the point of view of natural selection, which is a meta-phenomenon. Or you can go down several levels and look at it from the point of view of the gene. Different models are fruitful for different purposes. I do not know anything about this particular situation, but I doubt that the fact that there are four models is a problem for experts in the field. If it was a problem they would probably have winnowed out the three least accurate ones. If experts in the field are arguing about this issue, and trying to push three models out, then I guess there is a problem. Do they say this is an issue? Even mistaken and oversimplified models are sometimes used because they are convenient. And if you takes a peek at the Earth's past climate, it is apparent that > forces are at work that are far more influential and complex than the > relatively simple carbon dioxide driver. > I expect this would take a great deal more than a "peak" to establish. Certainly I myself am not qualified to make this determination. > You tend to disregard the 16 year heating pause, dismissing it offhand > because it is not possible according to your beliefs. > No, I dismiss it for the reasons explained by the UK MET office, and for the reasons Mel Miles was pissed off when then the NHE pulled that same stunt on him. See the the book "How to Lie with Statistics" for details. > May I ask you one simple question if you are planning to respond to this > post. Do you honestly believe that the current climate models accurately > take into account all of the important variables and their interactions > that predict future climate? > I'm sure I made it clear that I am not qualified to judge this issue. However I am sure that current climate models are fantastically better than they were 30 years ago, because they predict the weather so well. As I said, being able to predict the weather is quite different from predicting long-term climate change, but both are grounded in deep knowledge of the atmosphere and physics. It seems unlikely to me that you can make superb short-term predictions about a system if your overall model and knowledge of the system is as defective as the climate change skeptics assert. Okay, that is just a guess, but it beats speculating about four models you don't know in detail, and you don't work with on a day-to-day basis. I think it is likely that the climatologists have good reasons for keeping four models around, and you do not know enough about the subject to judge their reasons. Programmers keep many different programming languages around, and many different methods of doing systems analysis. Carpenters show up for work with six different kinds of saws and some strange looking hammers and mallets. We have our reasons. Amateurs should not assume they know why experts do what they do, and what all those tools in the toolbox are for. - Jed
