Don

Exactly who (or what bodies or institutions) are asking you/us to embark on this radical change of life - the giving up of coal-fired electricity, your petrol-powered car and the opportunity to see your children overseas?

Q&A:

The IPCC message, in both TAR and 4AR, is that a doubling of atmospheric carbon dioxide will be disastrous. Kyoto and the coming Copenhagen meeting have been about preventing this occurring. For that goal to succeed there would have to be a great reduction in our use of fossil fuels, which would be likely to have such effects. Who else? Hansen of GISS (for whom coal on trains represents 'death trains'), many of those who write essays and article on how to 'fix' climate change, the more extreme Green commentators, and all those who talk airily of the need to get rid of coal and oil and replace them with solar, wind, geothermal or whatever.

As I have said before, I am in favour of moving away from a dependence on oil, for the good reason that it is a finite resource that will become more expensive when the world economy expands again. I also think we need to manage water much better than we do. But these things are worth doing whether or not AGW is sensible.

That’s true Don, a doubling of atmospheric CO2 from 385 to 770 ppm would be disastrous, as the IPCC has said. However, what the UNFCCC are aiming for is 450 - 550 ppm (max) – this is not a doubling.

You would be aware of the reports given by Sir Nicholas Stern and Professor Garnaut (on their economic impact analyses of the IPCC report). They do not assert we would have to give up of coal-fired electricity, our petrol-powered car or the opportunity to see our children overseas.

The UNFCCC meeting in Copenhagen will try to have post-Kyoto goals put in place to limit our expected rise in temperatures to 2 degrees C by 2100. It will be intriguing to see the differing politico-econometrics play out, I am not optimistic.

Jim Hansen is an extremist (and very good at metaphor), as are some others you only allude to. Do you really think that the decision makers of this world are going to take all that the extremists say on board?

Don, there are extremists on both sides. People who don’t know you better could say you are an extremist from the other end of the spectrum. We will not have to give up of coal-fired electricity, our petrol-powered car or the opportunity to see our children overseas – that is just scare mongering like Hansen.

But, despite what the UNFCCC is aiming for, neither India nor China is prepared to follow suit, and unless they both do, on current projections atmospheric CO2 will pass the target. I see no evidence of a past tipping point, and the argument for it is metaphorical. As CO2 rises, and nothing is done, the extremists will raise their voices and the extreme views will have more traction — unless, of course, cooling has set in and the AGW alarm is put to rest until the next warming phase.

And I have an objection to doing things which on the face of them have no impact on global warming but cost us all. For me, AGW is the Great Distractor. And I thought Garnaut's language on parts was akin to the pulpit. I don't recall the same intemperance in Stern, but it's a while since I read it. And neither thought it was their business to pay due diligence to ascertaining how far the IPCC's prognostications were likely to be correct!

Yes Don, AGW is a distractor. We should be directing our efforts to sustainability (the world does not end in 2100). This in itself would treat the ‘symptom’ of human endeavour. The role India and China play is crucial, they must come on board – time will tell. I hope Clinton and Chu are earning their keep. It's worth noting that China is doing more than the US or Australia in adapting to, and mitigation against, global warming (their sheer numbers put them at a disadvantage). I have my doubts about Canada and to some extent, Japan and New Zealand.

In another thread, we shared thoughts about Noel Keenleyside's work (I don’t think they were pursued). In geologic time, we are heading for another ice age (many 1000’s of years away). In our own time, the temperature trend is up, despite natural and regional variation. If we are to grow/develop in a more sustainable way, we should start adapting now (which will take decades). It would also be prudent to take a responsible and measured approach to reducing our dependence on fossil fuels. People who think this will not, or should not, cost us anything are deluding only themselves.

My only real criticism of the IPCC is its reliance on the (dated) Special Report on Emission Scenarios. I am of the understanding that the formulation of the SRES was largely done by econometricians. I am also of the understanding that when AR5 is released (in 2014) more advanced economic modeling will be utilised. The IPCC’s projections (prognostications?) can only be evaluated in hindcast. Suffice to say that hindcasts have been reasonably good, despite natural variations in climate that can be attributed to volcanos and ENSO/PDO, for example.