Regular readers will be aware that I have a generally optimistic disposition. You may wish to bear this in mind when you read this Inside Story piece arguing that the prospects are good for stabilising global greenhouse gas concentrations at 450 ppm.
On the whole, though, I think excessive pessimism is a bigger problem than over-optimism. As I’ve argued before, I think lots of people have locked themselves into positions (eg advocacy of geoengineering, or belief in the end of industrial civilisation) that are based on the assumption that stabilisation is impossible. Many of these people are not open to evidence that stabilization is feasible, and even likely.
There’s a strong case that we should do better than 450 ppm, with a common ‘safe’ figure being 350 ppm. Since we passed that level some time ago, that requires a long period of negative net emissions, which cannot easily be achieved with current technology. Still, if net emissions are reduced to zero in the second half of this century, and some technological advances are made over the next fifty years (a plausible assumption if we put in some effort), even 350 ppm might be feasible.
Australia is dragging the chain under the Abbott government, but even Abbott seems to be feeling the international pressure judging by recent reports. With luck the last couple of years will turn out to have been a temporary detour in progress towards decarbonization.