Summarising the gobal warming discussion so far. My ‘global warming scepticism’ is simply that the evidence for catastrophic climate change is not clear. A sceptic naturally wants evidence for p or not-p, otherwise (if necessary) he is entitled to be sceptical about both p and not-p. Excluded middle does not apply to propositions embedded in the ‘sceptical about’ operator.
Now, there is a simple ‘textbook’ or ‘idealised’ climate model that can be easily explained, and is clearly nothing to be sceptical about. But this predicts nothing catastrophic (at least not for a long time). Now there is a much more complex model, which involves ‘feedback’ effects. But the problem there, as our commenter says is that “If you want a very simple explanation of how much warming you get from increasing CO2 by Y% then you can't have one: the full theory plus modelling of the earth system is too complex.”
This is a problem for scepticism. If we drop the Fermi assumption that all complex things can be explained simply, and accept that there are some things that are simply too difficult to be explained in a short time, it follows that there will be situations where a sceptic – who is a generalist – is unable to challenge statements made by a specialist. But if unable to do that, he is no longer a sceptic.
One ray of light, however, is that at least one of my several plumbing crises may not be as serious as I feared. A clever site here tells us, for any given rise in sea level, whether our property is flooded or not. It tells me that substantial parts of West London will remain above water even with a rise of 3m. Within 500 years, London may look like Venice. That is something definitely to be welcomed.