Thinking more about your comment overnight, Ken, Lynas does not directly say that his 5C and 6C scenarios are speculative in the book but he did refer to the PETM scenario as speculative in an interview on The Science Show. I think he would have done better to include them as examples of runaway climate change without linking them to any specific temperature levels.

He does make the point that we are releasing carbon into the atmosphere 30 times faster than 55m years ago (presumably based on Zachos) and 100 times faster than 251m years ago (presumably based on Benton). I recall the Stern Review (I think) saying that the change in climate from 4-5C (Lynas’ Five degrees) would be greater than a shift from 2-3C. Essentially the specifics become difficult at this stage because we don’t know how the major elements of the climate system will interact with each other.

The 2-3C scenario, according to Lynas, sees major problems in food production, with the drying heating and drying of the mid-temperate food bowls, the remobilisation of the Kalahari sand dunes enveloping Botswana, Namibia, Angola, Zimbabwe and Zambia, the drying of Central America, the SW of the US and problems with all areas that depend on melt water from mountain snow.

There is also the issue of rising sea levels which in the long term could be very serious if we choose to stabilise at 550ppm of CO2, roughly double pre-industrial times.

The reference system in the book is weird. The publishers didn’t want to interrupt the text and the compromise is less than helpful. Nevertheless when I look at Chapter 3 in more detail I’ll endeavour to link his claims with his sources.

His Five Degrees chapter is very much based on the PETM analogue of 55 million years ago.

My worry is that he doesn’t seem to take regard of the actual temperatures of the PETM. This graph indicates that it was considerably warmer but I’m not clever enough to work out exactly how hot it was. The third graph in this article by Paul Monk indicates that it could have been about 10C warmer. Lynas does say in the chapter that the sea temperature was estimated to have been 20C within 200km of the north pole at that time.

Lynas doesn’t cite any one authority, but he could have been persuaded by James Lovelock whose Revenge of Gaia makes extensive reference to the PETM event. At the time climate scientists seemed to play down the relevance of the PETM, but I was interested in the fact that David Karoly made mention of it the other night. And I’ve seen a few other references to it. Certainly the configuration of the continents was reasonably similar to today.

The Six degrees chapter is definitely based on the Permian-Triassic extinction event of 251 million years ago. He sees the trigger for this being the release of methane hydrates from beneath the sea. He says explicitly that we don’t know what temperature might trigger them but worries about those that are said to be fairly shallow around the Arctic Sea. His description of the effects is largely based I think on Benton, M. 2003 When life nearly died. (Thames and Hudson).

These effects are not explicitly related to temperature, rather to changes in the composition of the atmosphere and the sea. But temperature would be the presumed trigger.

I haven’t been able to find a review of Lynas’ book yet. There is an article in the Guardian which is really an outline. The book is available here in paperback (Fourth Estate) for about $28.

I’m hoping to do a review soon myself, but I can’t promise a searching critique of the scientific basis, not being a scientist.

Then I was planning to do something in more detail about the Three Degrees chapter, as that is the threshold for dangerous warming.

crickey needs peer review.

Hullo? What do you think YOU are? Chopped liver?

Brian, I would be very grateful if you could list some of the citations which Lynas’ uses to support these points. I am reasonably familiar with the scientific literature on global warming, and I’ve never seen implications like this in it.

Evolution does in fact take many generations; the reason that bacteria have evolved multiple resistance to antibiotics within a single century, is because the bacterial reproductive cycle is very short. E-coli (a fairly common household germ) has a reproduction time of 20 minutes. So, if you wipe out 99.9% of the little buggers in your dunny with Pine-o-Clean, two hours and twenty minutes later (10 generations) the population is back to its pre-Pine-o-Clean level. And, as you’ve effectively selected for Pine-o-Clean resistance, the little buggers are going to be a bit more difficult to kill next time you clean your dunny.

Rabbits and myxo – bad example. I recall from high school biology that there were a few strains of the myxo virus. In Europe, myxo is transmitted primarily by fleas which live on their host until it dies, then transfer to another. The deadlier strain of myxo is favoured by this environment – it gets to new hosts more quickly by killing off its current host. In Oz, the vector is the mosquito – mosquitos don’t feed off dead rabbits. This favours less virulent strains which don’t kill the host animal. But it’s the virus that is being selected, not the host.

In animals with slower reproductive cycles – measured in years, rather than minutes or weeks, the rate of evolution is much slower. And given the nature of the process, in a lot of cases (like that of our own species) we don’t know where it’s going – only where it’s currently got to.

Just look at all the examples…

Cheers…

Evolution takes many, many generations and does not operate in a significant way over that small a time frame.

Bollocks. Just all at all the examples of bacteria evolving into anti-biotic resistant forms, rabbits and the myxo virus mutually evolving toward a far more resistant rabbit on one hand and a less virulent variety variety of myxo on the other. There must doubtless be other examples of significant evolutionary change working surprisingly quickly, but these two will serve to demonstrate the principle. The fact that is that we don’t know how fast – or slowly – evolution may operate in many circumstances, and it would be foolish to rely on a naive belief that it must necessarily be slow and gradual.
Cheers…

This is not the first time McQueen has written a piece in Crikey implying that Anthropogenic Global Warming is a myth, generated by a combination of scientific conspiracy and a desire to place humans at the centre of the universe by making us the masters of our destiny, rather than corks in nature’s storms.

He doesn’t understand the science, doesn’t really even try because he thinks he knows the motivation of the scientists. For all his references to Popper he is being postmodernist in his portrayal of science uninfluenced from evidence.

For the record here are some clear predictions that have come from Global Warming. All of them have been confirmed with the exception of one which has half confirmation, for reasons we are starting to understand:

*Rising global average temperatures
*Greater warming at night than during the day
*Greater warming in winter than summer
*Greater warming at the poles than the equator
*Greater warming of the troposphere than the surface
*Cooling of the stratosphere

Yet McQueen has the gall to allege that climatologists don’t understand the basics of science and the need for testable hypotheses.