The experience with my car (below) made me think a bit. In fact, I often get asked about my position on global warming, now that I’m a ‘public scientist’. I don’t know about ‘position’ – but I do know something of how science is done. Meaning that scientific discovery is based on evidence, evidence that is interpretetd by PWKs (people who know what they’re talking about). So if the vast majority of the world’s climate scientists tell us we have something to worry about, we have something to worry about.
The key discovery was in the 1970s, when it was first realised that global climate might be an unstable system, i.e. a system where a small perturbation could easily result in a large effect. (There is a very nice description of this discovery in the book ‘The Discovery of Global Warming’ by Spencer Weart).
Nowadays, there doesn’t seem to be any doubt that
(i) the atmosphere is heating up (the part near the earth, that is)
(ii) the rate is unprecedented
(iii) the phenomenon is almost certainly due to human activity (e.g. carbon emissions)
These results have been confirmed by the Intergovermental Panel on Climate Change, an unprecedented global coalition of scientists. Despite much debate over details, there isn’t much debate about the overall trend (except among a tiny minority of scientists, some of whom who have an industry bias). Of course there are also genuine scientific doubters, but the consensus is pretty clear…
The debate now more concerns what action to take – in other words how to reduce emissions without triggering a recession. There is certainly sharp disagreement here, but on close inspection it is more between scientists and economists. For example, it’s worth noting that Bjorn Lomborg, the prominent skeptic, is not in fact a scientist at all. Lomborg, and several other economists and political scientists, claim that tackling emissions would be very inefficient and essentially a waste of money that would be better spent elsewhere. However, scientists point out that many such commentators have two things in common –
1. They tend to play down the evidence of warming (Lomborg’s infamous book The Skeptical Environmentalist is a prime example of this)
2. They ignore the possibilty of a tipping point. What scientists worry most about is that a threshold may exist, beyond which there may be no going back as positive feedback mechanisms kick in … a frightening scenario
So the great global warming debate is beginning to look like a debate between scientists (who don’t really understand economics) and economists (who don’t really understand science). For my part, I find Lomborg’s grasp of scientific uncertainty highly suspect (economics can be spectacularly wrong in a way science never is)..pretty worrying in a man who was recently voted one of the 100 most influential people on the planet by Time Magazine…
What happens if Lomborg’s wrong? I often wonder if those who make a career out of questioning the consensus ever doubt themselves. If we do sail past a tipping point, thanks to delayed action due to the skeptics, they will have a lot to answer for…