This is in response to an e-mail, which asks: "I wonder if you could enlarge on your global warming scepticism?
1. Is it not a fact that there is less ice over the North Pole, and that glaciers are retreating all over the world?
2. CO2 is a greenhouse gas, and as a result of burning fossil fuels over the last 200 years we have increased the proportion of CO2 in the atmosphere by 50%.
Does it not seem likely that 2 has contributed to 1?"
- no denial that there has been significant warming, esp. through the second half of the twentieth century, the issue is about the A of the AGW (ie how far is it anthropogenic);
- the level of CO2 in the atmosphere has been rising consistently since industrialisation;
- the temperature has not displayed anything like a linear relationship with CO2;
- the temperature has fluctuated significantly in previous centuries without any regard to CO2 (and, I believe, has been warmer than today eg in the Medieval Warm Period);
- I'm therefore dubious about the anthropogenic element, and I haven't seen very much that convincingly links the temperature shifts to human activity. It's a reasonably plausible hypothesis which I find, at present, 'not proven'.
I could well be wrong. I don't think that AGW is a 'hoax', I think that there is a perfidious industry of 'climate change denial' and I am quite open to the idea that human activity has indeed had an effect on the climate change. However, even if AGW is true, I see it as largely irrelevant because a) the peaking of fossil fuels places an absolute limit on emissions (at a much lower level than the IPCC expect, and which will achieve vastly more than any inter-governmental agreements like Kyoto or Copenhagen) and b) we need to change our behaviour (we will be forced to change our behaviour) anyway due to the many other limits to growth.
In other words, I'm starting to see all the fuss about climate change as being like an engineer rushing up to tell the captain of the Titanic that he needs to shut down the engines because if he doesn't, they are likely to blow up in a day or two, and the captain says 'Engineer, we've just struck an iceberg!'
I'm also getting more sceptical about the way that the church is latching on to the issue (and, indeed, on to Peak Oil). I think that we miss the point of our calling if we hitch our behaviour to contemporary issues. We need to live sub specie aeternitatis whatever the science tells us.