Dung it's all BS. We are wasting out time, but it keeps the dementia at bay. I suppose.

Geronimo, of the four beliefs you attribute to me in your part 4, only the fourth is largely true. The others are false. I am surprised you can read what I said (which is quite clear) and come to such comprehensively wrong conclusions. But I'm often surprised here.

As you reject the existing range of probability distributions (for temperature rise resulting from CO2 increases), perhaps you can outline your own distribution. Don't say there isn't one because every decision in every sphere of life and science is based on an assessment of probabilities. So what probabilities do you assign to temperature rises of between 0C and 5C for a doubling of CO2 and with what justification?

Hunter, I assume your outburst comes from a sudden realization that you have no logical basis for your views.

Radical, the sermon you posted was just a waffly gish-gallop. There was nothing there worth commenting on.

Language is a strange thing. I have noticed "Gish-gallop" frequently employed by those of a certain persuasion.

But it's not yet at the levels of "It's worse than we thought".

Shub, probabilty distributions are all around us. We could for fun plot the probabilty distribution of 1, 2, 3 and more of you having the balls to state a probabilty distribution for temperature for double CO2. I reckon there is a vague possibility of one of you being brave enough to try an *honest* attempt at such with sensible justifications; for more than a few the chances are vanishingly small. And there is the distribution.

Thing is, you just can't do it for temperature and retain your "skeptical" outlook. Once you start quantifying and justifying you have to start giving non-zero probabilities to temp rises of several degrees and more. Then your world falls apart.

And Geronimo is not about to examine his views deeply enough to do it. He's happier in his imagined world where he totally misunderstands and misrepresents my (and probably most "warmists") views. The certainties are less challenging there.

Raff I have no idea what the temperature will be with an increase 0f 1C will be. The PDFs you set great store by are an attempt at guessing the probability of a temperature increase based on barely understood feedback mechanisms. ALL the empirical studies show and ECS of less than 2C as far as I can tell. I don't believe that's a basis for policy making.

Dung I've been trying to make this point for a while now. According to the IPCC an increase of 1C will cause temperatures to rise by 3C, so how come the Minoan only got to 2C. I wish I could understand all this climate science stuff. Applying logic and common sense to observations doesn't seem to get you anywhere.

Shub:

"What does that tell us about the specific risk in question? Almost nothing."

Not true. If you estimate the probability of something like being killed in an airplane you can come to a pretty precise answer. It is tiny but there's enough data to know the result. But plot a temperature rise probability distribution using the relatively poor available information and you come away being able to say with certainty neither where the peak probability is nor what the probability of a 2, 3 or 4 degree rise is. The graph is not a sharp peak, indicating relative certainty, but spread out, indicating high uncertainty. So just the process of trying to plot a graph shows clearly that we can't be at all sure whether doubling CO2 will raise temps by only 1c or, say, 4C. Not that the chance of 4C is minuscule, like the airplane, but that it is unknown.

So if you ask a company the chances of their service killing you and they say 1 in a million, you might not turn a hair. If they said the risk was unknown, how would you feel then? Similarly if the risk of earth warming 4C if CO2 emissions don't fall is essentially unknown then who would think continuing business as usual a logical option?

Before you start saying that 4C is really not likely and we shouldn't be concerned with the possibility, remember that you are effectively claiming knowledge that nobody else has.

Precision is not accuracy.

"Geronimo, of the four beliefs you attribute to me in your part 4, only the fourth is largely true."

Apart from a touching belief that scientists understand and can model the climate what are your beliefs? I must say that our exchanges have been reasonably polite, but you come on here insulting the intelligence of people and making accusations of unspecified stupidity, so why not tell us what you believe is going to happen if we can't stop CO2 emissions?

I really would like to know.

'Language is a strange thing. I have noticed "Gish-gallop" frequently employed by those of a certain persuasion.' michael hart

Be fair, warmists only have a few arguments so a certain amount of recycling is to be expected even when the phrases are unfamiliar with international audiences. Another I dislike is "swift boating" (still don't know what either of them mean) but our side is guilty with "jumping the shark" and let's not mention Monckton's Latin.

However our references to Hitch Hikers Guide to the Galaxy are entirely acceptable because if you don't understand who the B Arkers are you don't deserve to be commenting.

Good to know that you're the kind of person who knows where their towel is Radical Rodent ;-)

Geronimo, I thought it was clear. Like everyone else, including all those here, I don't know whether warming from doubling CO2 will be 1C or 4C, somewhere in between or beyond. I'm pretty sure 4C of warming would have really bad consequences and so it is sensible not to go down that path.

Raff, there's a new article at the Guardian which quotes some expert or other that current commitments for the Paris meeting will amount to reducing CO2 effects by 2 years in 2036. So everything that's been done and will be done in Europe and the US and every other country signing on the dotted line so far amounts to 2 years. Not being sure if it's going to be "1C or 4C, somewhere in between or beyond" is why. People aren't going to commit themselves to much while the research is still so vague. And even those countries who lay out a reduction path are lying unless new, reliable energy sources emerge. All those jamborees like Paris are a WASTE OF TIME until the science and the solutions are sorted.

Raff, I'm afraid it wasn't clear to me, and it's always best to get to the detail. Personally I probably hold much the same view as you except that I don't believe 4C will be bad, why should it be?

Clearly I'm older than you - in primitive societies you never here anyone taking counsel from the "village youngers" for good reason, they lack what you can't get without time, experience. All the elderly curmudgeons on this blog have been round a long time and can remember forecasts of future doom from way back. When I was at school we were going to run out of coal by the end of the 20th century, we were going to have a nuclear war with Russia. When the coal didn't run out we were going to have "peal oil" and a nuclear winter caused by a nuclear war. Then scientists told us we were moving into an ice age, that there could be a worldwide pandemic of bird flu, causing out government to stockpile £500M of tamilflu. These are just a few of the myriad scare stories we've had in our lifetimes. How would you have reacted to each of these (I guess you'd certainly have spent £500M on Tamlflu) forecasts of doom? We simply cannot react to the worst case forecasts of, nutters, and I use that word unashamedly to describe people who forecast doom and gloom out into the future.

Thanks for talking, I guess when you get down to it and stop believing you're cleverer than "deniers" there's a nice person in there somewhere.

"Gish-gallop" (= EM complaining that too many references have been quoted.)
"swift boating"
"jumping the shark"

People who pick and use up the latest verbal mannerisms as a way of saying "Look at me - have you noticed how I'm up to date and in with the in crowd?" are pathetic.

While I'm at it, I sometimes get the feeling that I'm the only person who regards estimating ECS, whether from climate models or from observed temperature changes, as an exercise in complete futility.

Tiny, what is being proposed is indeed insufficient. It will take a crisis to change that. But we do have alternative tech, including nuclear, hydro, wind and solar.

Geronimo, I've lived through most of those events too but I wonder how deep scientific support for each went. Not so much I think.

...there's a nice person in there somewhere

Some people think so, but I've never found him.

Martin, when a term fits, why not use it. When someone trots out a line of half truths, fallacies and untruths pretending to be offering serious argument, what else do you call it?

Estimating ECS clearly gives an uncomfortably large range of possibilities. Unless you are able to reject the largest part of the range on spurious grounds in order to make yourself feel comfortable.