Wednesday, April 09, 2008

Climate Change Sceptics

Don Aitken has got coverage in today's The Australian for a speech he gave on climate change.

Aitken has done a remarkably good job of dealing with the justifiable doubts about anthropogenic global warming. In particular I support his eminently justified critique of the attempt to be doctrinaire about the so-called consensus. I could also quibble about his description of Paul Feyerabend as a political theorist rather than a philosopher of science, and to simultaneously assuming there is an established “scientific method” while also quoting approvingly from Feyerabend’s Against Method, which was an argument that there is no privileged scientific method.

In the end all we can have are theories, and we can have theories that are largely useful or theories that have been useful but are now less so, and eventually some of those theories may become “discredited”. With climate change we have a theory of the Greenhouse Effect; a theory I first heard at an ANZAAS conference in 1975 as an argument for nuclear power and hence treated by me with excessive scepticism.

It is a plausible theory, it is a difficult theory to fully demonstrate and model; primarily because weather patterns are what we now call chaotic systems. To the extent that there is evidence to support the theory it is “patchy” – the ice core correlations don’t prove cause and effect, short run warming measures are hard to interpret.

But Aitken also wants to discount a “precautionary principle”, based on a simple criticism of Pacal’s reason for believing in God – namely that in doing his expected value analysis the father of probability theory left out some other possible future states. However, in this case while there are multiple alternate theories there is still a simple binary choice between the “Greenhouse Theory is correct” or “it is not correct”.

The matter is very like the Pascal’s though in pay-off – acting to reduce emissions has a relatively low cost compared to the catastrophic outcome if the theory is correct. And just like Pascal, we can’t wait to make the decision. If we wait to see incontrovertible evidence of warming then we are too late to stop the process escalating. The one thing we do know is that the CO2 concentrations in the atmosphere are already at monstrously high levels.

I have elsewhere likened the issue to a General who refuses to believe the intelligence reports of a paratroop invasion until he sees the first invader on the ground. By then the other thousands are in the air on the way down and there is nothing he can do about it.

Finally, climate change reaction may in the end be just what we need. The theory known as “peak oil” is that the global economy will receive a massive shock when energy demands keep increasing at the same time as oil supply starts to decrease. The steps taken to reduce reliance on fossil fuels will also ease the risks of that shock.

What I find a pity is that the climate change discussion has become clouded in the same kind of pointless dialectic as the so-called culture wars - where persons on either side seem to think direct attacks on the other as being wrong in method are productive or useful. Aitken is right to raise his concerns about the climate bandwagon - but his proposed solution of a giant process to decide the "right" scientific answer is also wrong. We have to accept that at this point multiple theories have degrees of evidentiary support - the question is how to act in the face of that, not on how to decide "the truth".

Tuesday, April 08, 2008

Double Vision

The good news is the gas bubble (with its edge of blood) has gone now. The bad news is that I seem to now have "fourth nerve palsy" which means my left eye doesn't point the same way as my right.

This means I see two images, and as my left eye vision improves the second image is getting stronger. The doc thinks it might have been pre-existimng but that my brain always compensated for it - but now we just have to wait to see if that is the case.

If not it is either glasses with a prism effect or surgery to remove a bit of muscle. What fun?

No Hope for Liberals

There is now conclusive evidence that there is no hope for the Liberal Party. They have announced that Henry Ergas will be undertaking a review of their tax policy.

Ergas in the article is given a title that I don't think he is entitled to, but the absebce of that qualification alone is insufficient to invalidate his role. It is more that his only area of expertise is really regulatory economics, not macro policy issues and certainly not tax. He has no access to a General Equilibrium model to assess the affects of any proposed tax changes across the economy. And most tellingly, his last foray into this territory was embarrassing.

In 2007 Ergas prepared a report for the Menzies Research Centre (no active website!) on the issue of State and Commonwealth expenditures. This was designed to underpin the Costello claim that it was the States putting pressure on interest rates with an old-fashioned crowding out argument. This ignored the fact that the capacity constraints in the economy were in part due to lack of infrastructure spending by the States.

But worse, he tried to argue that the GST windfall to the States had been frittered away on "unearned" wage increases, that is wage increases not tied to productivity improvements.

His analysis was flawed because the evidence was the States had to respond to the general movement in wages in the labour market, and in a tight labour market with skills shortages it was the private sector that was leading in wage settlements. This was not an era of Whitlamesque government led wage increases.

His second problem was that he had blessed little meaningful data on productivity in the major employing areas in the States - health, education and policing. Further he had no idea of how productivity gains (usually achieved through the introduction of new technology) could be achieved in those sectors.

It should be an interesting tax policy when it is released.