Scientific modeling

From a comment at

http://economistsview.typepad.com/economistsview/2009/07/thomas-schelling-on-climate-change.html


Bill Jefferys says...

dr science wrote

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We agree that demeaning and lying is no good. But models are for making predictions. Models are not scientific knowledge.

The climate models have not been tested EXPERIMENTALLY. Predictions based on climate change models have not been verified.

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There are two kinds of science, experimental sciences like laboratory physics and chemistry, and observational sciences, like astronomy, and as it turns out, climatology.

In the former you can go into the lab and set up an experiment. In the latter, you have to wait for things to happen. I happen to be an astronomer. I cannot do an experiment in which I make a supernova blow up at my pleasure. I have to wait for it to happen. But the agreement of the predictions of my physical models of supernovae with the data that we obtain when the event happens is evidence that the physical model is correct. The better the agreement, the stronger the evidence. The model IS the scientific knowledge.

Similarly, climatologists cannot make things happen. They cannot adjust the carbon dioxide level at will to see what happens at various levels of that gas, nor can they adjust the number of sunspots to see what will happen as that goes up and down. No, just like astronomers, they have to wait for things to happen, and see if their physical models accurately predict the data.

So, dr science is wrong. He'd have a point if climatology were an experimental science, but it isn't. If climate models accurately predict the data, then that is evidence that they are correct. The better the agreement, the stronger the evidence. And, contrary to what he asserts, the model IS the scientific knowledge.

Posted by: Bill Jefferys | Link to comment | Jul 15, 2009 at 11:04 AM