Monday, May 11, 2009

Now looking at the sun

I'm sure I've mentioned that I'm something of a climate change skeptic. I'm more than willing to accept that the climate's changing because I doubt it's ever been static. I'm also happy to say that the I can see the logic of the whole idea that what man is up to may affect the climate. What turns me off is that the science is so dependent on computer modeling and, well, why should I believe that those who have designed the models are any better at their job than those who designed the system that gave us derivatives and mortaged-backed securities and the rest of that mess.

Okay, maybe that's a cheap shot, but the problems in the financial world were more than partly caused by too many young techno-heads developing all sorts of products that the banking professionals never fully understood, never really grasped that a couple of key assumptions were faulty. Why should I assume that climatologists haven't made a similar error?

The whole thing just seems to me to be too complex for modeling, particularly when science is only now having to check their warming expectations with a less active sun.

Computer models suggest that of the 0.5C increase in global average temperatures over the past 30 years, only 10-20 per cent of the temperature variations observed were down to the Sun, although some said it was 50 per cent.

But around the turn of the century things started to change. Within a few years of the Sun’s activity starting to decline, the rise in the Earth’s temperature began to slow and has now been constant since the turn of the century. This was at the same time that the levels of atmospheric carbon dioxide carried on rising. So, is the Sun’s quietness responsible for the tail-off in global warming and if not, what is?

… If the Earth cools under a quiet Sun, then it may be an indication that the increase in the Sun’s activity since the Little Ice Age has been the dominant factor in global temperature rises. That would also mean that we have overestimated the sensitivity of the Earth’s atmosphere to an increase of carbon dioxide from the pre-industrial three parts per 10,000 by volume to today’s four parts per 10,000. Or the sun could compete with global warming, holding it back for a while. For now, all scientists can do, along with the rest of us, is to watch and wait.