Modeling climate change is not exactly trivial
I’m glad to see that others are echoing the point I made recently about climate change.
Scientists have substantial evidence to support the view that humans are warming the planet — as carbon dioxide levels rise, glaciers melt and global temperatures rise. Yet, for predicting the future climate, scientists must rely upon sophisticated — but not perfect — computer models.
“The public generally underappreciates that climate models are not meant for reducing our uncertainty about future climate, which they really cannot, but rather they are for increasing our confidence that we understand the climate system in general,” says Michael Bauer, a climate modeler at NASA’s Goddard Institute for Space Studies, in New York.
Most people know very little about computer models. I guess that many are still enamored with the concept of computers and they assume that since computers are involved the results must be accurate. Models are really little more than sets of equations and assumptions, some empirically based, others analytical, that are solved with the aid of computers. The computers only add speed and repeatability to the solution of the predetermined equations.
The two most glaring “faults” (inherent drawbacks is probably a more apt term) with models is that they require a litany of assumptions and cannot accurately predict chaotic behavior. The latter issue is pretty self evident, but the former could stand a bit of elaboration. Assumptions, in technical terminology, are simplifications. For example, one of the first problems that might be posed to an engineer in an introductory dynamics class is solving the trajectory of a baseball. In order to make the problem solvable for a novice, the professor will likely to tell the students to ignore drag, wind, rotation of the ball, etc. Those assumptions make the problem more easily solvable, but they introduce error into the student’s model of the ball’s trajectory. That is a very, very simple example. Just imagine how many assumptions must be made to model the entire earth’s very complex climate - not to mention the associated, and equally unpredictable, human actions - for a period of decades.
Errors propagate with time and eventually invalidate models. Personally, I think that the scientists making bold, dire predictions about the long term results of global climate change should be more forthright about the validity of their models.
Related content:
- A global warmitarian loses faith
- Global warming predictions were overestimated. I’m just shocked.
- Sweet irony
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