For those of you avidly following the slugging match between myself and bullying science blogger Kate of The Anterior Commissure on the topic of global warming, I highly recommend reading New Scientist‘s “Climate Change: A guide for the perplexed.” This feature is billed as a debunking of climate change myths (perpetrated mostly by its deniers) so some of its tone is a little testy, but overall this is the most comprehensive and fair-minded analysis of climate change and its attendant controversies I’ve read, a welcome change from the usual alarmist and poorly contextualized coverage. I will say that perhaps too many counterarguments are rejected by referring to the IPCC report as holy writ, side-stepping the accusations of critics that the reports themselves are a product of an over-hyped and politicized point of view. Then again, the IPCC reports do seem to represent the current consensus of climate scientists and I’ve seen no particularly compelling critique that suggests they should simply be dismissed.
Overall, the picture that emerges is of a broad consensus among climate scientists that a significant process of climate change is occurring, caused in great part by the release of extra CO2 into the atmosphere from man-made sources. This theory is based on CO2’s properties as a “greenhouse gas,” which means that CO2, along with various other gases in the atmosphere, absorbs radiation from the sun and so causes the atmosphere to get warmer. This, coupled with a strong correlation between CO2 levels and global temperature observed far back into the past (by tapping into air bubbles trapped in polar ice and the like), leads to the conclusion that the extra CO2 produced by us naughty humans is causing and will cause global temperatures to rise. While short-term weather conditions are too chaotic to predict with great accuracy, aggregate climate conditions over much longer periods of time – decades or centuries say – can in fact be predicted with some accuracy, as the parameters within which the climate oscillates – such as absorption of the sun’s radiation – are far more stable.
The extent to which temperatures will rise and what the effect of those changes will be are a lot more unclear, however, with climate modelers conceding that major factors such as cloud cover and the release of sulphate aerosols* into the atmosphere – and the assumptions that they make about them – create a good deal of uncertainty about what’s in store. It is, for instance, rather unclear whether warming oceans will create ever more ferocious hurricanes or instead produce cuddly little kitten storms. And many of the drastic changes reported in the newspapers with such alarm are in fact forecast to occur only over the next 100 years.
None of this is to suggest that action isn’t warranted. Let me put it this way: rather than basing pretty much our entire civilizational prosperity on carbon-based fuel, wouldn’t it be better to try and find an alternative to carbon-based, non-renewable energy sources, stores of which may run out in the course of our lifetimes and reliance on which puts us at the mercy of psychotic fundamentalists, grotesque dictators and delusional butchers while their emissions make our climate radically unpredictable at best and intensely damaging to life, liberty and the energy-intensive pursuit of happiness at worst?
*A product of heavy industry whose concentration in the atmosphere is thought to have actually had a cooling effect from 1940 to 1970, and which ironically was eliminated by clean air legislation. The heavy use of sulphates by newly industrializing nations such as China and India may have a similar effect, although some aerosols warm the atmosphere rather than cooling it.