I recently left a comment over at nice Mr Watts' place. It received a favourable response, so I thought I would expand it a little and reproduce it here. The relevant background is that a number of commenters had explained that they had been subjected to abuse when leaving comments on another blog (which shall remain nameless but which does not welcome comments from me). That blog takes an extreme view on the catastrophic man-made global warming issue. Its editorial policy appears to be that the IPCC's computer games are beyond any criticism whatsoever and anyone who dares to challenge any part of them is too stupid to understand the issues and/or actuated by malice or greed.
Some practitioners of an infant science might say “this is our hypothesis, now we’re going to study what actually happens and make any necessary adjustments”. But not, it seems, those wedded to this particular idea. They like to say “the science is settled” but it seems to me that they really mean “our minds are closed”. On hearing that some measures suggest global average cooling within the last decade rather than global average warming, they reply in two ways and adopt both replies, mindless to the conflict between the two.
On the one hand they assert that measured cooling is not cooling at all. This is just legerdemain, by selecting particular starting and finishing points they create trend lines on graphs to argue that lower readings from thermometers actually display continuing upward movements in average temperatures. Yet you only need to adopt different start and end points to show something different. On the other hand they say “this is what should be expected because warming causes cooling”. No. Warming means temperatures going up, cooling means temperatures going down. You cannot create ice by applying heat to a pan of water, nor can you bring tepid water to the boil by adding ice. These two positions are wholly contradictory.
There is a credible explanation available to them but it involves a concession of uncertainty, so they will not propose it. They could say “temporary blips are only to be expected because we are dealing with a vastly complex interaction of factors and we do not fully understand them all”. That would stand alongside their hypothesis and would not cause the batting of a single eyelid. But it would require them to accept that they do not know everything and, therefore, that their hypothesis has not yet been proved. Such a position appears to be unacceptable to them because they have pinned their colours unequivocally to the “the science is settled” mast.
Acceptance of uncertainty lies behind all honest debate, whether scientific or otherwise, until such time, if ever, that all the evidence points in one direction and nothing that is observed in real life is inconsistent with the position being advanced. Unjustified certainty requires dissenting voices to be dismissed rather than challenged on the merits of the points they put forward. Debate and challenge are the tools of those with open minds. Scoffing, sneering dismissal is the tool of those unprepared to accept that their belief in a hypothesis might not be well-founded. It is also the tool of those who know their hypothesis can be subjected to legitimate challenge but are not prepared to risk the personal loss (whether financial, reputational or both) that would result from such a challenge being successful.
What makes their certainty all the more absurd is that they are forever tinkering with both their hypothesis and their computer models, something that would be wholly unnecessary if they really had all the answers already.