Science – The path from unsubstantiated hypothesis to experimentally-verified theory, more to the point – requires that we come up with models, which then lead to predictions of the result of experiments in the realm of the hypothesis. These predictions, if borne out by experiment (the model is not falsified), validate the hypothesis and then we have a theory with laws (that is, rules for models we can use to predict.) If the predictions are wrong, they falsify the model and we are back to, or still have, an unsubstantiated hypothesis. We get to try once again, if we still think the hypothesis has merit, hopefully with more information at hand the next time around.
Now, the problem with the AGW hypothesis is that the models which are making the predictions are not matching the actual results. These climate models never worked well at both the poles and the mid-latitudes; they failed to predict the current long-lasting stall; the rates of temperature rise predicted don’t match, when rise actually does occur; and so what we have here are hypothesis that are not producing rules that we can use to predict their notional basis. With regard to predictions made of future performance, as that future has not arrived, as the near-term predictions have failed, there is no basis to presume that the models are verified long term.
The issues that the hypothesis deal with are issues of great potential concern: waters rising, temperatures changing in what we think might be an unfriendly manner, and of course the degree, if any, to which we ourselves may be responsible for this and what this implies for the actions we ought to be taking.
But sit back, look at the science, that is to say, the success of the model at hand to generate successful predictions, and ask yourself: Is it time to use this as a basis for major decision making?
To put it into perspective, If I proposed an hypothesis that said dollar bills could survive in a specific chemical environment for 4 hours, but when this assertion is tested, some bills did, and some bills didn’t… would you be ready to commit to putting *your* money in the jar for 4 hours, or would you want to wait until the model correctly predicted which bills survived, and which did not, and then check over your bills, before you did anything as committal-heavy as putting your liquidity at stake?
The AGW models have inputs of concern. No question. At this time, they (there are several major model variants) make very poor predictions indeed. Also no question. Yet we are being asked to accept the predictions (not the idea of warming, but the predictions of the model) as if it were a tested, validated theory; to act decisively (and expensively) upon predictions, even though many have demonstrably failed to date; to accept as useful law, models that have not stood up under real world conditions.
This is why a skeptical viewpoint is appropriate at this time. It is also why a scientist who is not a climatologist can evaluate the science from outside, as can an informed layman, without great familiarity with the climate.
The questions to ask are: Does the the hypothesis give rise to a model with testable predictions? If yes, and that seems to be the case here, then the next question is, are the results compatible with the predictions made? The answer here is presently no — we have this stall in temperature rise; we have the failure of the models to predict across all latitudes; we have sea level changes that don’t match the predicted results.
Given this situation, we reasonably can, and we should, ask the proponents of the AGW hypothesis and models to go back to their workbenches and refine those predictions. When they get it right (and they may yet do so), that is the time to get behind policy decisions that use the science — because when the predictions work, then it is science, in the sense that now, finally, one has a theory.