One of the things which is great about science is that any hypothesis is supposed to get consideration as long as it cannot be eliminated by observed results. In other words, a hypothesis is not dismissed unless it is impossible. So we are open to any explanation that can work, which means that there should be no possibility that the true explanation is excluded a priori. Of course, when ideas are rejected it must be because they cannot be reconciled with experiments. This is of course only one of the good things about science. But it distinguishes science from, say, religion, wherein explanations of phenomena must be reconcilable with beliefs rather than facts in order to be considered valid hypotheses. It is similarly important in science that no explanation be excepted unless every concievable alternative has been eliminated.
To put this in simple terms, science is open to anything that can work, and all possible hypotheses are equal unless 1. one is contradicted by the evidence or 2. one is less plausible. Thus, if we have two equally plausible hypotheses which are both consistent with the observations, we must conclude that either could be correct. Most importantly we must consider them equal so that we can test both to determine which is incorrect and so we do not undly favor one hypothesis and thus try to show it to be correct and ignore contrary evidence in favor of the alternative.
Unfortunately, it appears that the IPCC Lead Authors are unreceptive to considering alternative hypotheses to their own. John Christy recently argued before a group of them that alternative views should be given consideration if evidence can be presented that they are valid. He had such evidence. However, their reaction was “cold“-not one of them welcomed the idea of such consideration of alternative views. From the perspective of the Lead Authors, hypotheses are not created equal, and alternatives should not be given consideration but rejected out of hand. This is bad for science, because science thrives on the testing of all valid hypotheses because any could be correct. Effectively they have decided that only one set of hypotheses can be correct. And they are willing to distort the evidence in favor of those if necessary.