Global Climate Change is probably the most complex challenge ever faced by humans, and in its entirety well beyond the comprehension by the human mind. The tool best suited to gaining a comprehension of the various individual elements, and their interactions, is computer modeling.
To over-simplify the process, in computer modeling the basic postulates are reduced to mathematical equations, woven together in a manner thought to resemble the workings of the natural system, and then tested against a set of real, observed data. The equations are then adjusted and the model re-run to obtain a better fit between the observed data and that predicted by the model. This process of testing, refining the model, and retesting is often referred to as “calibration”, and continues until the model is either completely rejected, or provides answers that are in agreement with the observed data used in the test. At this point, the model is flipped around and used to predict the future, on the basic premise that if it can predict the known past with a high degree of accuracy, it has some value for predicting the unknown future. In the real world, the entire process is begun anew and repeated as new scientific data becomes available. Computer models should never be assumed to be the ultimate, final answer; rather they can be a very useful predictive tool, outlining and ranking probable outcomes, and pointing the way for future research.
Computer models have been invaluable as we begin to understand GCC, and have generally provided excellent, accurate predictions, with the exception of the time element. Scarcely a day goes by that the newspapers do not report that some predicted event is occurring at a far faster rate than the models predicted. This, in itself is extraordinarily useful information as it confirms that GCC is occurring at a rate that is far faster than anything we have experienced in the past. And secondly, it tells us to pay extra attention to the science, as it is tending to be too conservative and under-estimating, rather than over-estimating climate change.
