Much needed due diligence on climate change

Is the global warming likely to lead to a dangerous increase in sea levels?

The IPCC currently predicts that there will be a rather larger increase in the 21st century, of perhaps 2-3mm per year. Its middle estimate might lead to an increase of perhaps 30cm over this century. Even if that is accepted, there is no warrant here for the claims that Tuvalu, the Maldives and other low-lying island micro-states, or coastal towns in Australia or Florida, will be devastated.

Let us move then to the modelling of climate.

When learning about computing in the US 40 years ago I discovered that if you made a mistake in your input the output from the computer was rubbish, notwithstanding the apparent precision of the numbers in the printout. There was a phrase for it: "GIGO", or "garbage in, garbage out".

Commonsense tells us that if our current knowledge of climate and weather cannot provide forecasts with much accuracy past 24 hours, we don't know enough about the inter-relationships inside the model, no matter how much data we have, even supposing it be perfect data. It is important that the work be done, and modelling is a valuable intellectual activity in its own right. Yet it is these contemporary, unvalidated models that are the basis of the Kyoto Protocol, carbon trading and the climate change policies put forward by our political parties.

To repeat, models are models; they are highly simplified versions of reality, and cannot provide evidence of anything. One recent example, showing a truly catastrophic climate outcome in 20 years' time, was based on the assumption that the central global warming hypothesis is correct. It was then used to show why we must do something now about reducing greenhouse gas emissions. When I was a young undergraduate that kind of argument was known as an "intellectual coup d'êtat": you assumed what it was that you had to prove, surrounded it all with words (or in this case, numbers), and laid it on the table in triumph. I was astounded that no one objected.

What I see is something that the political theorist Paul Feyerabend wrote about a long time ago in Against Method (1975): the tendency of scholars to "protect" their theory by building defences around it. As each new paper that proposes an alternative to one or other aspect of AGW appears, it is as though it has to be ignored, rubbished or noted but dismissed, rather than accepted as a valid contribution to the debate.

Why does this continue? When the Royal Society in London has to issue a paper crushing anyone who asks inconvenient questions, or where the President of our own equivalent body issues a public statement saying that 'those who deny human-induced global warming are in the same camp as those that deny smoking causes lung cancer and that CFCs deplete the ozone layer" you begin to shake your head. This is not at all in the tradition of the best science. It is the language of the boss.

We seem to be caught up in an "availability cascade": we judge whether or not something is true by how many examples of it we see reported. Fires, storms, apparently trapped polar bears, floods, cold, undue heat - if these events are authoritatively linked to a single attributed cause, then almost anything in that domain will seem to be an example of the cause, and we become worried. I should say at once that "climate change" has become the offered cause of so many diverse incidents that for me at any rate it ceases to be a likely cause of any. Why does this particular availability cascade have its evident force? I offer some reasons.

One is that some of the senior people in and around the IPCC - one might call them "scientist-activists" - are convinced that unless the world wakes up to itself humanity will not have a future. I would call this a quasi-religious view, and it is the basis of the view that "the end justifies the means", a doctrine that I think has no place in a democracy. A second is that there are now thousands of people, not the least of them scientists, whose work depends on the AGW proposition and the large amounts of money that have flowed to institutes and universities because of it.

National scientific academies are now in the happy position of being powerful, at least in this domain, and they have become political in an apparent attempt to protect that pleasant power, whatever its impact on science.

A third is that the Greens and environmentalists generally welcome the AGW proposition because it fits in with their own world-view. Governments that depend on Green support have found themselves, however willingly or unwillingly, trapped in AGW policies, as is plainly the case with the newly-elected Rudd Government. The hard heads may not buy the story, but they do want to be elected or re-elected.