In defending Al Gore and his apocalyptic vision of climate change Mark Lynas makes the following statement:

Hence the need to move the debate from science and towards precaution. It is now very likely that global warming this century will present major challenges to the survival of human civilisation – and to our children\’s and grandchildren\’s lives. If we listen to the deniers, we are taking a very dangerous gamble – a bit like playing Russian roulette with five bullets and only one empty chamber. That\’s not a game I want to play with my kids.

But this is exactly the point at issue: global warming in this current century will not present major challenges to the survival of human civilisation. Thus, actions based on this premise are unwarranted.

If we are to believe the most extreme of the serious analyses (The Stern Review) then climate change will cost 20% of GDP in 2100. And that\’s throwing everything including the kitchen sink in there. And that\’s 20% off an economy that will be 3 times larger than it is now.

This isn\’t the end of civilisation, this is civilisation being not quite as good as it could be. Reactions to this situation should therefore be proportionate, not the emergency crash program which the end of civilisation might require.

In the eyes of many environmentalists the IPCC have become “deniers”. Nothing less than the end of human civilisation will make them happy.

One must remember that global warming is a bit of a rachet mechanism. Once it has happened it is a hell of a job reversing it on a human rather than geological timescale. Thus whilst I take your point, it needs to be framed in the fact that this a potentially permenant change being wrought and thus the costs continue into perpetuity.

All that said, don’t the environmentalists realise that hardly anyone buys the fact that civilisation will collapse as a result. It just makes the whole movement seem preposterous.

Point taken, but rising sea levels over the next 50-100 years could present some major challenges to the entire world, including many developed nations.

Mark Lynas is this guy, whose book states that if temperature rises by more than a couple of degrees, which it will unless we curb emissions sufficiently by ~2018, then all sorts of nasty things will happen that will force the temperature up even higher – the ignition of the rainforests, albedo effect at the North Pole, etc. I saw him talk about it. Very convincing, but of course one never knows how the numbers add up without being an actual climate scientist. You have to start taking somebody’s word for it at some point.

Letter from a Tory,

We are talking about the sea level rising in inches not feet. Southern England has been happily sinking for thousands of years without causing “major challenges”.

Anyway, global warming must be a hoax – how else can you explain the governments plans to build in the Thames Gateway?

@ Letters From a Tory

You haven’t actually read anything about this debate at all, have you?

The whole issue of sea level rises in the next few years has been judged Alarmist by the High Court.

If it happens at all, it will be in 1000 years. Its a bit like the vikings worrying about health and safety issues while on a pillage!

If I use small words it may help. Al Gore lied in his film and the sea isn’t going to rise in your life time, the polar bears are not drowning and hurricane Katrina was not caused by global warming.

Now, if you are old enough, think back to all the other scare stories you have heard and see what happened to them – e.g. Y2K, Aids, Ozone Layer, Just Say No, Ice Age by 2000? etc!

1/ The information content of computer models of climate is indistinguishable from zero.

Computer Climate models are multi-variable recursive functions, which are subject to exponential error via their inherently chaotic behaviour.

2/ CO2 is plantfood, not a pollutant.

Al Gore can change the climate as much as Yassir “Aids” Arafat could make peace with Israel.

FOul, errr, the concerns about AIDs were well-founded and the risk of UVB radiation courtesy of ozone depletion may be also. Certainly the media loves a good scare but a damn-near incurable disease that lies dormant for years allowing you in your ignorance to infect those closest and most intimate to you ranks as a damnably scary thing. Visit sub-Saharan Africa to see what joy it brings to people.

Computer Climate models are multi-variable recursive functions, which are subject to exponential error via their inherently chaotic behaviour.This sounds awfully impressive. Have you published your findings?

Note that it’s unlikely – indeed impossible – that the costs will be nicely evenly distributed by sector and in time. That’s not a 20% cut in the rate of GDP *growth*; a 20% cut in output across-the-board.

But in the nasty scenarios, we could get that in a short time frame. Has there ever been anything similar? Gt Depression?

Tim adds: OK, let’s call it the Great Depression all over again. A rise in GDP up to some point then a heavy fall. At the most extreme end of this argument, should we not have had the growth from 1830 to 1930, in order to avoid the subsequent 20/30% cut from this new higher level of GDP? A hard argument to make successfully I would think.

A less extreme version. Should we manouvre so that we end up with GDP slightly lower than it would have been, after the crash, but without the crash? Given the way that humans hate losses much more than they appreciate gains, a strong argument.

My view? If we’re going to be talking about GDP levels then, clearly, we should be talking about GDP levels. Amongst the SRES families we have stories about how we can maximise those. So if that is indeed what we want to do, maximise the GDP levels of those who come after us we should, if we are to be logical, be arguing for the A1 family plus some form of emissions control. Or perhaps incentives to create non CO2 emitting energy production…..

That last is roughly my view. Work to make our descendants as rich as possible first, then add on top of that CO2 reduction.

“Hence the need to move the debate from science and towards precaution.”

Translation: We can’t provide a scientifically robust proof, so let’s just start a panic instead, like we did with DDT and the MMR vaccine.

This whole pantomime has very little to do with science, and rather a lot to do with venal political ambition, and rabble rousing. Stampeding the public is the oldest trick in the book.

Hence the need to move the debate from science and towards precaution.We must all sacrifice to Gaia! Bring out your firstborn…

In this day & age, who would think

anyone(except perhaps a Pope) could frame an argument in terms of ‘moving away from science’….and be believed and followed..?Computer Climate models are multi-variable recursive functions, which are subject to exponential error via their inherently chaotic behaviour.

This sounds awfully impressive. Have you published your findings?

Chaitin has!

Chaitin has!A Google search hasn’t revealed where this author showed climate modelling is inherently vulnerable to exponential error, or this error’s connection with chaos. Can you provide a reference please?

Try these

http://www.cs.auckland.ac.nz/CDMTCS/chaitin/sciamer2.html

http://www.fortunecity.com/emachines/e11/86/randwalk.html

I assume this is a joke.

Those pages don’t mention climate modelling, or exponential errors, or anything implying exponential errors. Nor do they mention the “multi-variable recursive functions” of ACO. The second of them mentions chaos, but in passing, and in a dubious apparent equation of the concept with randomness. The rest is a pop-science intro. to Chaitin’s metamathematics.

Even allowing Chaitin’s extravagant claims for the importance of his random halting problem findings, he does not even claim relevance to climate modelling, or the solution of partial differential equations generally.

So… all very funny, but do have any serious point to make?

Here we are dividing the problem into two component parts ,the mathematical component that drives the physics, and the arithmetical numerical simulations.

It should be emphasized that most of the scientific community concerned with climate models are generally not interested in mathematical problems and treat a model as a specific finite-dimensional construction with a specific description of physical processes, thus reducing

the study of the model’s quality to a numerical experiment alone.

I recommend you read more on the Diophantine equation and Hilberts 10th problem and even Mataysevich’s proof that as well known opens more doors then it closes.

Here we are examining the aspects of modeling, its attributes and its limitations and certainties.As Norbert Wiener said “One of the chief duties of the mathematician when advising scientists is to discourage them from expecting too much from mathematics.

Or as more succinctly stated by Vladimir Arnold as follows

“Mathematics is a part of physics. Physics is an experimental science, a part of natural science. Mathematics is the part of physics where experiments are cheap.

In the middle of the twentieth century it was attempted to divide physics and mathematics. The consequences turned out to be catastrophic. Whole generations of mathematicians grew up without knowing half of their science and, of course, in total ignorance of any other sciences. They first began teaching their ugly scholastic pseudo-mathematics to their students, then to schoolchildren (forgetting Hardy’s warning that ugly mathematics has no permanent place under the Sun).

Since scholastic mathematics that is cut off from physics is fit neither for teaching nor for application in any other science, the result was the universal hate towards mathematicians – both on the part of the poor schoolchildren (some of whom in the meantime became ministers) and of the users.

The ugly building, built by undereducated mathematicians who were exhausted by their inferiority complex and who were unable to make themselves familiar with physics, reminds one of the rigorous axiomatic theory of odd numbers. Obviously, it is possible to create such a theory and make pupils admire the perfection and internal consistency of the resulting structure (in which, for example, the sum of an odd number of terms and the product of any number of factors are defined). From this sectarian point of view, even numbers could either be declared a heresy or, with passage of time, be introduced into the theory supplemented with a few “ideal” objects (in order to comply with the needs of physics and the real world)…….

….At this point a special technique has been developed in mathematics. This technique, when applied to the real world, is sometimes useful, but can sometimes also lead to self-deception. This technique is called modelling. When constructing a model, the following idealisation is made: certain facts which are only known with a certain degree of probability or with a certain degree of accuracy, are considered to be “absolutely” correct and are accepted as “axioms”. The sense of this “absoluteness” lies precisely in the fact that we allow ourselves to use these “facts” according to the rules of formal logic, in the process declaring as “theorems” all that we can derive from them.

It is obvious that in any real-life activity it is impossible to wholly rely on such deductions. The reason is at least that the parameters of the studied phenomena are never known absolutely exactly and a small change in parameters (for example, the initial conditions of a process) can totally change the result. Say, for this reason a reliable long-term weather forecast is impossible and will remain impossible, no matter how much we develop computers and devices which record initial conditions

Ah. Another Tim Worstall fan from the Bob B random pasting school of argument.

I’m tempting to delve into why, for instance, you think diophantine equations have any relevance to numerical modelling, but I have other things to do. So I’ll just ask two questions:

1. Where do chaos, exponential errors, and ACO’s “multi-variable recursive functions” come in to any of this, even if I accept your general claims regarding modelling?

2. Why, if what you say about mathematical modelling is true, haven’t we simply junked all of physics? Even if I accept your pasted in excerpt on teaching mathematics as true and relevant, why would it only apply to climate modelling?

Valentine magic