As we shiver our way through July records are popping all over the place. Readers will be pleased to know that if we call these events extreme, we are just climate change freaks inventing a new metaphysical category in order to sustain our irrational belief in anthropogenically-generated climate change. Or something.
Humphrey McQueen, freelance historian, Marxist intellectual and the author of many books and articles, none of them on climate change as far as I can see, entered the climate debate on Crikey the other day equipped with Popper and a fertile mind, just to sort us all out. Good of him, really.
He suggests that the “Climate-Change” band heralds every rise in temperature as evidence to support their “hypothesis” but until recently has been perplexed by â??inconvenient truths such as the occasional severe winter.â?? To overcome this little problem they have invented the “Extreme Event”.
The “Climate-Change” faithful now have the power to levitate above the embarrassment of awkward evidence. To deal with exceptions, they have conceived the metaphysical category of the “Extreme Event”. This phrase does not refer to weather which has extreme consequences, such as the past 48 hours in Victoria. The significance is altogether different. The “Extreme Event” is a device for ruling out the very possibility of contrary evidence and, thus, for denying the prospect of Popperian falsification.The “Climate Change” sophists proceed thus: the anthropogenically-enhanced greenhouse effect does more than push up average temperatures. It also increases instability. So, while a denser greenhouse mostly makes the planet hotter/drier, it will also make it colder/wetter in some places at certain times.
Hang on a minute. Hold it right there, Humphrey!
First of all an extreme weather event is not a metaphysical experience unless you are on something or perhaps praying at the time. There are records for weather stations all over the place and events that are measured as falling near the extremities our outside the range for that place or region can rightfully be termed extreme. This is a matter of measurement.
Records are being broken all the time, indeed more frequently, I understand, in recent times.
Humphrey says:
while a denser greenhouse mostly makes the planet hotter/drier, it will also make it colder/wetter in some places at certain times.
Well yes and no to some degree. It can also be hotter/wetter and colder/drier. More importantly his statement isnâ??t the best way of explaining what is going on.
In very simple terms the planetâ??s hydrological cycle is amplified with global warming. More water will evaporate. The atmosphere has a higher saturation point, so it can hold more water up there. And when a the conditions are right for the atmosphere to dump itâ??s load more is likely to come down in any one event.
Also drier air at the surface is often colder as well as warmer. Water stores heat, so a moister atmosphere keeps the temperature more even.
As the planet warms it heats up more over the land than the sea. Overall there will be more rain, but not necessarily on the land.
Circulation patterns will be changed. The temperate weather systems, the low pressure systems that used to move across southern Australia bringing winter rain, are said to be moving towards the poles. The effect of this as warming proceeds is that the subtropics become drier and the higher latitudes become wetter. In Europe this manifests itself with drier weather in southern Europe and more rain and a tendency to floods further north, a trend already in evidence.
McQueen is right in saying that itâ??s â??pseudo-science to attribute every hurricane or blizzard to an amorphous “Climate Change”. What in the name of fortune is wrong, however, with observing that specific events fit in with an emerging pattern of change? Especially if it fits with the output of the dreaded models.
Let me be clear here. Single events do not usually count as proof of climate change. Climatologists normally look for a 30-year pattern of change in weather before they consider it of significance in terms of climate change.
If we are experiencing a cold winter, the first thing to ask is whether it is local or general. McQueen would have done well to look at the NASA GISS datasets and images. If he looked at the one on the top left heâ??d see a few patches of current cooling around the globe in a strong warming pattern. One of them happens to be over the eastern part of Australia. But these cooling patches shift around over the years.
What I observe happening as I look at the weather maps each night is that recently we have been scoring large lows over the Tasman with a large high covering most of the continent. They are ripping cold air from the south and shooting it up to North Queensland. They might bring some moisture onto land but by the time it gets to Brisvegas the air is very dry. Our maximums have been thereabouts, but it is cold overnight especially away from the coast. The wind has been the killer for me.
Does this mean anything in terms of climate change?
Firstly, the global pattern of warming doesnâ??t seem in any danger of imminent collapse. There is plenty of orange on the map and the five-year trend graph of the temperature is climbing strangly.
Secondly, the pattern of large lows over the Tasman in the middle of winter doesnâ??t mean much unless they persist for another 30 years or so. But new patterns of highs and lows are to be expected with climate change generated by global warming.
For all his eloquence McQueenâ??s position on AGW/CC is far from clear. Does he believe that there is no warning, or just that there is no evidence that humans contribute to warming. Does he believe that there is no link between warming and climate change? He seems to be saying that individual â??extreme eventsâ?? have no bearing on the AGW/CC â??hypothesisâ??. Yet he also seems to be saying that a bit of cold weather in this part of the globe is a Popperian falsification of the “hypothesis”. Surely not!
What is clear is that he doesnâ??t understand the difference between weather and climate. Nor does he understand the basics of the earthâ??s hydrological cycle.
. . . and you can’t tell me whether the net cost-benefit of places that are better off under climate change, whether through natural or man made casues, versus places thar are worse off, will be positive or negative.
And let’s not forget that the Black Death performed an excellent service in making real estate more affordable for hard-pressed families who managed to survive the epidemic.
crickey needs peer review.
Crikey let’s in some strange ones – the fact that they occasionally let Peter Faris “QC” write for them is beyond belief.
People should make a very clear distinction between saying “climate change is not happening” and “climate change is happening but is not man made.” The latter as an argument for doing nothing about it is like saying “the house is on fire but I didn’t start it, so I’m not going to try to put it out.”
Climate change science makes predictions which can be falsified.
One is that, conditional on increases in the quantity of greenhouse gases in the atmosphere will cause increases in world average temperatures of between 2 and 6 degrees by the end of this century.
So why has it been so cold lately? Because it’s the middle of winter.
“. . . and you can’t tell me whether the net cost-benefit of places that are better off under climate change, whether through natural or man made casues, versus places thar are worse off, will be positive or negative.”
You can. Best estimates to date are in the Stern Review. If anyone thinks they can provide better estimates than Stern, they should.
Bah. Falsification is overrated and overused as a condition of what constitutes science anyway. I’m sick to death of someone popping up to explain science by invoking Popper. Theories and the process of science are far more complex than such simple reductions of process allow.
Death to Popper. Long live Feyerabend!
As in your penultimate para. Weather is not climate. We are short lived creatures but anybody who hasn’t heard the ‘oldies’ talking about strange weather must not know, or listen to, any.
Failing that, check out your garden; even if you’re the ultimate, vertically stacked urbanoid even a manicured city park or the Botanic Gardens will be replete with unseasonal, previously unrecorded forward shifts in growth cycles.
In the BM west of Sydney 40 & 50 year residents confirm that it is the coldest they can remember (sic!)but the bush tells another, longer story.
It shits me that the old chestnut of “haha you’re calling it climate change not global warming now because it’s not hot at the moment” keeps popping up. For the record, the Intergovernmental Panel on CLIMATE CHANGE ( http://www.ipcc.ch/) was established in 1988.
But 99 per cent of the talk in support of climate change as a scientific theory that we get to hear of comes from non-scientists, usually politicians and MSM hacks. And they have no qualms about using terms like ‘extreme weather events’ in a non-scientific sense. It’s similar to the mix up creationists have over the use of the term ‘theory of evolution’.
An even worse example of damaged rhetoric in the climate change debate is the constant claim that ‘we cannot predict what the results of climate change will be’.
If you cannot predict what the results will be, it’s not a scientific theory! It’s a perfect example of scare politics masquerading as science.
McQueen is right.
Quite so. And even if Razor’s fantasy comes true and global warming produces a global Kaldor-Hicks optimum*, there remain some far from trivial problems, including:
1. How do we arrange for the winners to compensate the losers on a global scale (especially if the losses entail mega-deaths and disabilities, and entire countries and regions becoming uninhabitable)?
2. What about irreversible biodiversity loss and irreversible loss of other ecological and environmental values which mightn’t be able to be assimilated into Razor’s CBA methodology?
*********************************************************
* A Kaldor-Hicks optimum occurs when there are winners and losers, but the aggregate wins outweigh the aggregate losses so that the losers can be fully compensated, meaning that at least some people are better off and nobody is worse off.
You can’t predict what the results of evolution will be in 100 years either, TimT.
I think they let Humphrey McQueen on Crikey to have an equivalent left-wing kook to Peter Faris QC and the like. Not only has he been talking crap about Climate Change, but he also came out with some positively ignorant rubbish about Dawkins and the “New Atheists” recently too.
Very disappointing.
The trouble with people who work by themselves, as McQueen does, is that they have no colleagues who can look over their work and tell them they are talking horse shit, before that work gets into print.
Predictions can, and have, been made about the theory of evolution.
Further to Katz – the Ice Ages provided the fertile soils of the American midwest, the European lowlands and the Chinese and Indian river plains – in short the agricultural foundations of civilisation. That’s not to say any of these places would have been habitable at the time, indeed quite the reverse.
OTOH, some places back then were much more pleasant than now – Lake Mungo, for example. These places supported the 0.01% of today’s human population that were around at the time. To summarise – the ending of the nice Goldilocks climate that allowed the rise of civilisation may in the long run (when we’re all dead, to paraphrase Keynes) benefit some small geographic pockets.
However, unlike the last Ice Age, present human population distribution and geopolitical organisation doesn’t allow for the majority of humanity to exploit these through migration, and the rate of expected change is far higher than at the onset of the Ice Ages. To put it another way, large masses of humanity are likely to find themselves living in places that won’t support large masses of humanity, and with nowhere to move to (eg Bangladesh). I’m not sure that megadeath is appropriately addressed by cost-benefit analysis, Razor (and this was Katz’s point).
Still, like with all catastrophes, there will be some who benefit. There were some, even in the defeated side, for example, for whom the second world war was an opportunity for enrichment amid the suffering of the many.
Then again, it’s possible you’re in fact a climate change skeptic, Razor, and that your post was merely a cheap debating point…
I can: virtually no new species.
Evolution takes many, many generations and does not operate in a significant way over that small a time frame.
One of the more droll contributions to the debate in the lead-up to the ABC’s screening of Durkin’s Downfall was an Age opinion piece by denialist Ian Plimer which included the statement that the IPCC modelling of climate scenarios for the next 93 years are faulty because they don’t take account of the effects on climate of continental drift and mountain formation.
Mmm, while I was writing my post Paul Norton gazumped my points. Sorry to bore you all.
On McQueen, I’m not at all sure he ever disavowed his Maoism… last I heard he still thought the mass murderer formerly known as the Great Helmsman’s political program was the very acme of paradigms for human political organisation.
Youâ??re right Patrick, and my comment was lazy. I wasnâ??t so much making an argument, as â??falsifyingâ?? TimTâ??s. We donâ??t know exactly how species will mutate in the future, although we know they will and I assume some biologists can make educated predictions about it. That we donâ??t know the exact effects of the theory for the future doesnâ??t disprove evolution was my point.
But 99 per cent of the talk in support of climate change as a scientific theory that we get to hear of comes from non-scientists, usually politicians and MSM hacks.
But that invalidates your comments on it too Tim, since you aren’t a scientist. neither are Michael Duffy or Ray Evans (dear old things!), not even close, even though they were presented as “experts” on the post – GGWS discussion on the ABC last week.
Helen, my complaint is that the commentators are non-scientists, but the language they use almost always confuses scientific and non-scientific language – and I gave two examples of how they did it.
Often, this confusion is quite deliberate, and is done in an attempt either to win votes (by scaring the voters), or to win readers (by posting deliberately shocking headlines and stories.)
Although I don’t have an issue with the concept of Global Warming/Climate Change in principle. And I ceratinly accept that the current evidence supports the thesis that the Earth’s climate is in an Inter-Glacial period, I am less sanguine by the projections of impending doom or, the opposite, that everything will be alright.
An interesting essay by Cory Doctorow on “The Progressive Apocalypse and Other Futurismic Delights” explains the psychological imperatives that can lead to distorted projections either towards utopia or apocalypse.
Anna – I missed your point, apologies.
I get very frustrated with the “it might be good for people/the environment” line of reasoning – biodiversity is one of the big elephants in the corner of the room that is generally overlooked.
Climate scientists and all reactionaries are paper tigers.
Can’t tell how the results of evolution will look in a 100 years, says Anna.
If the startling results of the ‘So, is it O.K?’ post are to be believed, no humans will be left on the earth because reproduction will stop.
What a bummer! I was hoping we’d eventually evolve into something half decent.
“If the startling results of the ‘So, is it O.K?’ post are to be believed, no humans will be left on the earth because reproduction will stop.”
They would be startling results if they led to anything like that conclusion.
Psssst… Daniel… over here mate…
Sex acts aren’t mutually exclusive. Pass it on.
If they were, I’d have to choose between having kids and blowjobs. Don’t you EVER put me in that position.
FDB, I have no interest in putting you in any position!
Oh Humphrey.
The first thing to know is that the weather system is anoscillatory one. The next thing to know is that if you add energy to an oscillatory system the amplitude of the oscillations MUST increase. This is basic, really basic, physics. Thus you will get hotter hot, wetter wet, dryer dry, and colder cold and windier winds. The energy added to the atmosphere and top bit of the sea (50m) by a 1C rise in temperature is of the order 1X10e26 Joules this is about the energy realeased in the Cretaceous extinction event or about 100 million Hiroshima type bombs.
Also rising sea temperature expands the water and reduces its CO2 absorption capacity, that further increases the “greenhouse effect, first identified by Arrenhius in the latter part of the 19th century
Get back over the other side of the CP Snow divide Humphrey, you have no business here. You are making an idiot of yourself
Huggybunny
Well here’s the views of a fairly eminent economist (obviously a lefty though)
Kenneth J. Arrow explains why something must be done to limit global warming even if the Stern Report inadequately discounted future costs.
http://www.bepress.com/ev/vol4/iss3/art2/
Paul Ian Plimer was on the Science Show on 30 June putting his latest idea that the CO2 comes fron earthquakes (transcript available).
There was a thorough Fisking of his contribution at Le Rayon Vert.
Tim T, “non-scientists, usually politicians and MSM hacks” can mangle the climate change terminology, as you say. McQueen, however, is not restricting his criticism to non-scientists.
On winners and losers, Mark Lynas’ book Six Degrees spells out the implications, as far as can be ascertained from the scientific literature, for every degree of warming up to six. You don’t go far on this path before there are more losers than winners (we are just talking humans here). With 3 degrees (ie. 2-3C) you get whole slabs of the planet uninhabitable. With 5 degrees, it’s the South Island of NZ, maybe Tasmania, a circle around the Arctic and some high plateaus in the tropics that remain habitable. With six degrees it’s like the Permian-Triassic extinction event of 251 million years ago, when Homo Sapiens, not to mention all the other species, would be under threat.
I have reservations about the last two scenarios, but we would be in ‘runaway warming’ territory at that stage, so he could well be right.
Huggybunny on 20 July 2007 at 5:05 pm
‘Oh Humphrey.
The first thing to know is that the weather system is anoscillatory one. The next thing to know is that if you add energy to an oscillatory system the amplitude of the oscillations MUST increase. This is basic, really basic, physics.’ …
Huh? First you say ‘the weather system is anoscillatory’, then you say it’s oscillatory.
Hey, make up your damn mind, will ya!
Then you say, ‘if you add energy to an oscillatory system the amplitude of the oscillations MUST increase’.
BULLSHIT! The sum of energy within an oscillating system is completely dependent upon the phase-relationship between the oscillations and the additional energy. Ever heard of PHASE, dummy?
Typical lefty drivel. You don’t even understand you own, so-called, ‘basic, really basic, physics.’
Stick to hugging bunnies, or whatever the hell you do.
leftybasher
PS Huggybunny – OK, I see you first error there was due to the lack of a space between ‘an’ and ‘oscillatory’. Oops, my bad.
My second point stands.
leftybasher
Wrong! Write 100 times “Phase is not a property of energy”.
Phase comes into consideration when you have two waves interacting to form an interference pattern. Where the waves are out of phase the wave motions will cancel (roughly speaking). Where they are in phase they will reinforce each other and the amplitude of the combined oscillation will be twice that of one of the two waves alone (assuming both waves are of equal amplitude).
As to the total energy in the whole system, it’s the combined energy of the two wave motions. Thanks to the Law of Conservation of Energy which “PHASE” does not override.
Thanks, Gummo, I’m in no position to arbitrate on the science.
Leftybasher, if you want to continue to contribute here, please cut the crap and do so with civility.
Sorry, Brian. I will try to contain my annoyance at dumb lefties in future…
Gummo, where did I say that phase was “a property of energy”? It is, however, a property of an oscillating system.
And I said Huggy was wrong in ignoring the point in the phase of the cycle of the system at which the additional energy was added. In-phase, it will add to the total; out-of-phase, it will subtract from the total.
No, not the whole story, but pretty basic physics, suffering as usual these days at the hands of simplistic ideologists.
leftybasher
leftybasher,
If you’re going to get on your high horse about “basic physics, suffering as usual these days at the hands of simplistic ideologists” I sugest that you first of all change your nickname and second address the basic science in a less confused manner.
First up, phase is not a property of an oscillating system, or at least not an intrinsic property. Phase is a relationship between two or more interacting oscillations. And this is complete nonsense:
Total what? If you mean total energy, you are advancing the absurd proposition that it is possible to reduce the total energy in a system by adding energy to it. A fairly clear case of basic physics, suffering at the hands of of a simplistic ideologist.
Any future comments you post will be subject to peer review before publication.
That would be a case of the cure being worse than the disease, a common enough prescription from the liberal-Left.
Leftybasher,
My comment re adding energy said nothing about phase.
The global weather patterns are so complex and chaotic that frequency has almost no meaning in this context.
Your babble about phase is meaningless in a system of this nature.
Huggybunny
Disinterested Observer, thanks for your comment and the link to the piece by Kenneth Arrow, who does seem to be a distinguished economist. It is said that he did outstanding work on the economics of uncertainty.
His final statement is:
In spite of the fact that he trained as a weather officer back in 1942, he has the good sense as an economist to leave the climate science to the climate scientists. Other economists please note.
He is persuaded by the seriousness of the foreshadowed outcomes if we do nothing to accept that p, the â??social rate of time preferenceâ??, should be valued at zero. He explains the meaning of p thus:
Iâ??m not an economist, but I canâ??t conceive of circumstances where you ever would. Wouldnâ??t such discounting be a value position?
Another point he makes succinctly is worth repeating:
Economists when modeling the costs and benefits of typically establish a reference scenario based on â??business as usualâ?? fore the economy ignoring the effects of climate change. The problem with this is that it can give the false impression (eg. to media persons and pollies) that there is actually a possibility of a penalty-free business as usual future.
I can’t remember where, but a few months ago I saw some posting in the blogosphere invoking a number of scientists who supposedly supported their far-right position. Arrow was one of the names mentioned, which surprised me. Wish I could find it now.
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.
I’ve said this elsewhere but, why do we feed economists? Comprehensively wrong, constantly in their chosen (non)field. To have them opining on anything other than …anything.. is ludicrous.
By definition they know nothing about the real world – a constant dictum, drummed into those so inadequate in social or other useful skills as to study economics is “the theory is perfect but reality fails to conform.”
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…
Sorry. First sentence of above should read
Cheers…
Not quite bollocks Mick.
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.
Next: Hugh Morgan does paid maternity leave
On winners and losers, Mark Lynas’ book Six Degrees spells out the implications, as far as can be ascertained from the scientific literature, for every degree of warming up to six. You don’t go far on this path before there are more losers than winners (we are just talking humans here). With 3 degrees (ie. 2-3C) you get whole slabs of the planet uninhabitable. With 5 degrees, it’s the South Island of NZ, maybe Tasmania, a circle around the Arctic and some high plateaus in the tropics that remain habitable. With six degrees it’s like the Permian-Triassic extinction event of 251 million years ago, when Homo Sapiens, not to mention all the other species, would be under threat.
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.
Glen
Hullo? What do you think YOU are? Chopped liver?
Ken, I think Lynas himself would regard his 5 and 6 degree scenarios as speculative. On a quick look it is not immediately clear what he is basing them on.
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.
JG, I let your last comment through as an example of a pointless remark that adds nothing to the discussion and says more about you than it’s target.
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.