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The Forum > Article Comments > Global Warming Danger: Catastrophic? > Comments

Global Warming Danger: Catastrophic? : Comments

By Geoff Davies, published 8/2/2011

New work by James Hansen shows Antarctic ice melting at an exponential rate leading to 5 metres of sea rise in 89 years.

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geoff, just looking at the graph in your article global temperature relative to peak holocene temperature, it just looks like there are peaks every 100 000 years, interested in your views.
Posted by slasher, Tuesday, 8 February 2011 9:22:43 AM
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Another alarmist rant from a left of left wing perspective.
Posted by Sniggid, Tuesday, 8 February 2011 10:26:08 AM
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Hi Geoff , thanks for your advice , I filed it with the MIA Farmers advice eg; "The Darling River is finished as a River".
Posted by Garum Masala, Tuesday, 8 February 2011 10:55:36 AM
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There are sceptical climate scientists, there are climate scientists who believe in AGW, and then there is James 'Death Trains' Hansen, who stands only slightly below Al Gore in the Apocalyptic Self-Promotion stakes.

But enough ad hominem: I notice that your article has several charts showing claimed temperature levels over time, but none showing sea levels over time. Just an oversight? Or is this because they would reveal that the rate of increase in sea levels with temperature rises -- if there are temperature rises -- is far too slow to worry the human race? Just how fast DID sea levels rise during the Pliocene, anyway, and how do you know?

If and when your 'exponential' process ever speeds up to dangerous levels we will all be safely dead, so why panic? I prescribe a deep breath, a dose of http://tinyurl.com/46o7g4j and a good lie down. And next time Hansen calls, don't answer.
Posted by Jon J, Tuesday, 8 February 2011 11:25:13 AM
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How darreeee you skeptics question the entirely reasonable assertion of AGW.. agast!

(pssst..maurice...have you sorted General Otega for his soon to come 'climate debt' bonanza ? tell him to make sure he's opened his Swiss bank account in time, and don't forget the 'gift' to the Democrats once it comes through)

Why....GLOBAL WARMING is absolutely caused by our rampaging exploitation of the planet..and the RICH nations owe PLENTY to the poor nations.. ooops..wait.. sorry..that's on the 'Wealth Redistribution' agenda.. must have got my notes mixed up ....*red face*

Back to the point..... Yes.. AGW.. we have the science.. we have the data (Psst Dave.. did you tell our mates in mainstream media to supress that story about wrongly calibrated data collection sensors?.. you did ? great! keep the boys at CCX informed ok!)

It's a done deal.. when cap and TRADE laws come in... we can take truckloads of dosh of the capitalist pig nations and spread it among our human rights commissions in 3rd world countries... Oops... more wrongly assembled notes/talking points.. damn!
Posted by ALGOREisRICH, Tuesday, 8 February 2011 12:35:35 PM
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Geoff

go back and look at your own article. To my reading both the deep ocean sentiments and the ice core data agree that there were several episodes in the climate record where temperatures were higher than now.

However, Hanson et al say that if the figures are adjusted in this clever if rather obscure way then those irritating peaks are eliminated and, really, present temperatues are higher.

Silly us for not seeing this before.

Apart from these arguements being transparently ad hoc, Geoff, the paper simply draws attention to the fact that two different sets of fossil record say clearly that temperatures have been higher in pre-industrial times. I wasn't aware of the deep sea sediment record until just now.

It would have been better for your side not to say anything at all.
Posted by Curmudgeon, Tuesday, 8 February 2011 12:47:29 PM
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FEEDBACK FOLLIES

Thanks Geoff

Splendid precision, chaps. Five metres of sea level rise in 89 years. Well done, James and Makikiosan.

"To explain the difference between the ice core and deep ocean records, Hansen and Sato argue that there are several positive feedbacks that come into play at temperatures near the present temperature, and they would accentuate the tendency of polar regions more strongly than the rest of the globe."

Feedbacks are fun. If you can't reconcile your datasets, just infer a a positive (or negative) 'feedback' that - presto - allows you to get the outcome that best suits your confirmation bias.

Fascinating to see alarmists now retreating to the remote past - the mirror image of the distant future and often just as unfalsifiable - desperately seeking "evidence" for future apocalypse.

Your notion that a couple of degrees of warming would be "catastrophic" is puzzling, even if one accepts (i) a Victorian bushfire rating can be applied legitimately to a global event, and (ii) their imaginative (inferred, not proven)feedback forcings.

How can "ice sheets disappear", when the average annual surface temperature of continental Antarctica is between -25C and -55C? The coldest month recorded at Russia's Vostok Station (in the Australian Antarctic Territory) was August 1997 (-75.4C) and the warmest, December 1989, a pleasant -28C. Surely it will take more than 2C to melt (and move) kilometres-thick ice in deep basins (not on slopes)?

Incidentally, ClimateCodeRed's graph (deliberately?) refers to an IPCC (2007) 'forecast' of 2-3C. Yet the IPCC 3AR (page 744) emphasises: "we are dealing with a coupled non-linear chaotic system, and hence long-term prediction of future climate states is not possible."

For me, the only thing more intriguing than the Hansen-Makiko kind of alarmism is your belief that (i) 'warming' has a single cause; (ii) is dangerous; and (iii)can be reversed merely by turning down the global anthropogenic carbon dioxide dial.

Proving (and predicting) causality, especially in a coupled non-linear chaotic system that is weather/climate, is beyond the powers of even our best climate astrologers.

Alice (in Warmerland)
Posted by Alice Thermopolis, Tuesday, 8 February 2011 12:50:39 PM
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Thanks for that Geoff. Your reliance on the sound research of Hansen and Sato is appreciated and confirmed by several other research teams that show that the melting of Greenlands glaciers which form the worlds second largest icecap is almost certain to raise global sea levels by 7 metres. The Greenland ice cap will reach a point of no return (tipping Point) by 2040.

The facts are set out in a New Scientist article p 8 ( 9-1 - 2011 ) entitled "Greenland poised on a knife edge". Also See Mernild's models that show that after 2040 nothing will prevent the ice cap from vanishing entirely. Says Mernild "glaciers havn't responded to temperature rises. Even if warming stops, melting will go on"..... "it does not look nice"

Journal of Hydrometeorology,DOI:10.1175/2009JM1140.1
Posted by PEST, Tuesday, 8 February 2011 2:41:12 PM
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It's not the -75 degree temps. it's the ice is sitting in warmer water than freezing.
Posted by a597, Tuesday, 8 February 2011 3:11:11 PM
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'The danger from global warming may have moved from “Extreme” to “Catastrophic”.'

Far more accurate prophecies predict the earth warming a lot more than the leaned Professor predicts. The difference is that bible prophecy always comes to pass while Green faith built on extremely dubious 'science' is about telling fellow believers what they want to hear. Higher electricity bills will only hurt the poor. Hopefully the funding will shift to true science instead of this 'consensus' nonsense.
Posted by runner, Tuesday, 8 February 2011 3:21:12 PM
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Geoff. You quote research based on ice cores as evidence of the guilt of CO2 in the future demise of the planet as we know it. But the Vostok ice core showing many warmings and coolings over 400,000 years shows that temperature rise precedes CO2 rise by around 800-1000 years, and therefore cannot be caused by it. Your graph shows the Medieval Warm Period to have been cooler than today. A little more research, for example http://www.co2science.org/subject/m/subject_m.php will reveal several hundered peer reviewed papers showing that the MWP was real, global and warmer than today. Human history tells us that vines were grown 200 metres higher elevations in Germany, certain cereal crops were grown at higher latitudes in Scandinavia than today, and so on - all suggesting temperatures 1 degree C or more higher than today. The Minoan and Roman warm periods were the same - and all with no evidence of CO2 as the main driver. Yet another ice core (GISP2) shows warmings, for example at the beginnning of the Holocene as fast as 8 degrees in 40 years, and coolings such as 4 degrees in 20 years at the end of the MWP, all far faster than the minuscule rate of change which so excites doomsayers such as Hansen and yourself. Sea level has been rising since the end of the Little Ice Age, following a period of relative stability, but it is still lower over most of the planet than at the time of the Holocene optimum. Despite your claim to the opposite the rate of rise has not been increasing in the last hundred years and indeed the rate as determined from satellites during the last 5 years has fallen. It is very easy for people such as you to give an air of authority to half truths and dodgy forecasts and mislead the general reader. You shouldn't do it. An open-minded look at the forecasts of Jim Hansen since 1988, whether related to temperature, sea level, ocean heat content and so on, should be enough to convince you that he should not be your source.
Posted by malrob, Tuesday, 8 February 2011 3:34:49 PM
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COUCH CATASTROPHILIA

Hey PEST

Perhaps you should take Jon J's advice?

If and when your 'exponential' process ever speeds up to dangerous levels we will all be safely dead, so why panic? I prescribe a deep breath, a dose of http://tinyurl.com/46o7g4j and a good lie down. And next time Hansen calls, don't answer.[Posted by Jon J, Tuesday, 8 February 2011 11:25:13 AM]

From http://tinyurl.com/46o7g4j

"A letter published in Nature on 27 January explains how increased melting in warmer years causes the internal drainage system of the ice sheet to ‘adapt’ and accommodate more melt-water, without speeding up the flow of ice toward the oceans. The findings have important implications for future assessments of global sea level rise."

“It had been thought that more surface melting would cause the ice sheet to speed up and retreat faster, but our study suggests that the opposite could in fact be true,” said Professor Andrew Shepherd from the University of Leeds School of Earth and Environment, who led the study.

“If that’s the case, increases in surface melting expected over the 21st century may have no affect on the rate of ice loss through flow. However, this doesn’t mean that the ice sheet is safe from climate change, because the impact of ocean-driven melting remains uncertain.”

Where would we be without: "X remains uncertain", but its impact is sure to be BAD?

In Warmerland, one thing is CERTAIN,folks: NOTHING IS SAFE FROM CLIMATE CHANGE!

Alice (in Warmerland)
Posted by Alice Thermopolis, Tuesday, 8 February 2011 3:37:32 PM
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Curmudgeon -
The comparison is clearest in the third graph. "Zero" in that graph is the Holocene maximum temperature. In the paper they conclude that, with 0.7 degrees of warming between 1880 and 2000, the temperature had returned, at least, to the Holocene maximum by 2000. You can see that the maxima at 125,000 and 400,000 were only 0.5-0.7 degrees warmer than the Holocene maximum, yet sea level was 5 m or more higher than now. Conclusion: less than 1 degree more and we have the potential for 5 m or more of sea level rise. Other arguments, summarised in the article, indicate this could happen within this century.

Alice -
I didn't write the subheading, it was Editor: "Five metres of sea level rise in 89 years."
My article says "ice shelves disappear", not "ice sheets disappear".
Weather is chaotic, but that doesn't make climate (the long-term average) chaotic. Go learn more.
Uncertainty cuts both ways. What if things turn out *worse* than expected (as they are tending to do, actually)?
For evidence that human emissions of CO2 are the main cause of present warming, see my post http://betternature.wordpress.com/2010/12/08/still-warming/ .

malrob-
C02 was not the trigger for ice age warming, increase solar heating was the trigger and CO2 then amplified the resulting rise in temperature. This is well understood, see http://betternature.wordpress.com/2009/11/12/co2-lag-during-ice-ages/.
The anecdotal evidence you cite for MWP says only that parts of Europe were relatively warm. Mainstream consensus is that Medieval global temperature was not warmer than at present. Nor did it change by 4 degrees in 20 years. Sea level rate of change is quoted from Hansen.
Posted by Geoff Davies, Tuesday, 8 February 2011 4:01:30 PM
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Thanks Geoff

"Weather is chaotic, but that doesn't make climate (the long-term average) chaotic. Go learn more."

Shall do. Are you are claiming "long-term climate" is predictable? On what basis? Computer models? Established laws of climate change?

Why, for example, should the so-called standard climatological normal be a 30-year period, by WMO et al convention?

"Uncertainty cuts both ways. What if things turn out *worse* than expected (as they are tending to do, actually)?"

So-called Precautionary Principle, if that is what you are evoking here, has nothing to do with science. Is it more than a clever way of rationalising confirmation bias, prejudice? Whatever it is, it is not science.

As for future climate projections and/or "predictions", how is it that even peer-reviewed climate scientists now admit that: "strictly, the calibration and evaluation of climate model predictions is IMPOSSIBLE, as projections of climate change relate to a state never before observed?" (p2746)

Reference: Challenges in combining projections from multiple models, J. Climate 2010
http://www.iac.ethz.ch/people/knuttir/papers/knutti10jc.pdf

Furthermore, "there is little agreement on metrics to separate 'good' from 'bad' models". (page 2739)

"There is a concern that model development, evaluation and posterior weighting or rnaking are all using the same data sets," and so on.

So what do the modellers do? Mix them altogether and pray their biases, etc, cancel each other out. [Imagine if any other profession, such as medical research, acted in this way.]

You folk want a restructuring the entire global economy based on this kind of "evidence"?

Alice (in Warmerland)
Posted by Alice Thermopolis, Tuesday, 8 February 2011 4:45:35 PM
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Geoff Davies
look, I regret, your reassuring explanation answered none of my concerns, nor was it particularly relevent. The article has done immense damage to your own side.

Although I still have to go over this much vaunted paper, various "adjustments" seem to be required to make the record say what you want. This business about being back near the holocene maximum is highly doubtful and very strongly contested in the literature, as you know. It is far from clear we are even back near the medieval warming period peak - it is certainly not the case in Europe. Warmists have tried to contest that one by putting together dodgy multi-proxy analyses, only to have them fall over.

Therefore this business about comparing sea heights now and at the time you specified is almost certainly irrelevent until proven otherwise. Considerable work has been done on recent (slight) sea level increases. There was also a recent article on this site by a Cliff Oliver from the Uni of WA, who pointed out, with some authority, that this business about ice sheets collapsing is imposible. My suggestion is that you read it.
Posted by Curmudgeon, Tuesday, 8 February 2011 5:21:48 PM
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Curmudgeon-
I did address the question you raised, you've just shifted your ground in response. Your initial comment had a clear misconception: H&M have not argued that "present temperatures are higher" than any in the past. As you note, their data clearly show otherwise. The paper is about how much higher, and when. Now you're arguing about Holocene maximum and alleged MWP, which they do address but I didn't cover it in what is, after all, a summary.

You (and most others here) dismiss a major data set because you don't like the conclusion. You disparage it with phrases like "clever if rather obscure", "transparently ad hoc", and you make the usual insulting charge: "various "adjustments" seem to be required to make the record say what you want".

All of this *without* having read the paper itself, which includes extensive discussions of many issues concerning the reliability of data and interpretations.

At least Sniggid and others here just get on with their ad hominem slurs, without having to disguise them in pseudo-reasonable, pseudo-rational lectures.
Posted by Geoff Davies, Tuesday, 8 February 2011 7:43:50 PM
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How can anyone talk about pseudo rational anything, while actually referring to Hansen as an authority.

Any one who has been caught in such outrageous concocting & doctering of data as him, is hardly going to convince anyone other that the "true believer", or a fellow traveler.
Posted by Hasbeen, Tuesday, 8 February 2011 7:55:56 PM
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Geoff

As with most of this pleading you accuse us of everything you are doing.

But having studied the material in a little more detail it occured to me what this is really about. Hanson is trying to revive this discredited idea of his of big increases in sea levels. I recall him peddling the idea of the ice sheets breaking up, as opposed to melting,to get the big increases he required in just a few decades. (Look at what Cliff Ollier wrote on this site.) But he had to abandon his big seas concept in favour of less than one metre increase, as that was all the IPCC would give him, in part because they ran into this problem of ice sheets taking much longer to break up break up than the few years he required.

Now Hanson's high sea levels are back, but from a different direction. Just ignore the data set everyone uses in favour of this other one, gloss over all the problems of relating ancient temperatures to modern ones, assume temperatures will go up a degree - big, big assumption - wave away all the problems about ice sheets breaking up, and you have catastrophically high sea levels.

And we're the ones ignoring inconvenient data?

This paper is not so much bad as very, very thin. Really Geoff, you should have spotted it as a piece of ad hocery the moment you saw it. Why bother us with it?
Posted by Curmudgeon, Tuesday, 8 February 2011 8:12:16 PM
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curmudgeon "Why bother us with it?"

Because it's another opportunity to berate the unbelievers, by adopting a more then previously hysterical stance.

I don't mind Geoff's rants anymore, it's an opportunity to see religious fervor in our own time, the roots of a new fanatical religion (green).

I imagine this is what it was like in the dark ages when the masses were thrashed into madness about Jerusalem being in the hands of the Islamists and led to the Crusades .. a lot of parallels there.

They too were warned that it was catastrophic, people would burn, freeze, whatever was handy to frighten the masses and control their will.

Anthropologically interesting ..
Posted by rpg, Tuesday, 8 February 2011 10:25:09 PM
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Geoff. My reference to the MWP was not just anecdotal. I referred you to the CO2 Science website where you will find listed and reviewed over 800 papers from several hundred researchers in about a hundred countries. Your statement that it was local and not warmer than the present is totally at odds with the vast majority of research. Maybe your idea of consensus is Jim Hansen and Michael Mann. I notice even Mann now grudgingly admits to a ‘medieval climate anomaly’ as he can no longer deny it.
My reference to a 4 degree fall in temperature at the end of the MWP was clearly stated to be from the GISP2 (Greenland) ice core data. I suggest you look it up. For a start you could try http://wattsupwiththat.com/2011/01/24/easterbrook-on-the-magnitude-of-greenland-gisp2-ice-core-data/
The usual authority on sea level monitoring is the University of Colorado Boulder, not Jim Hansen. They were the source of my statement.
I won’t have space to debate what came first, temperature rise or CO2. Maybe another time. Perhaps now we should just ask you to provide us with some empirical evidence, not computer modelling or theory, that anthropogenic CO2 is causing temperature rise. There are a couple of $50,000 reward offers in the US for the first person to produce such evidence; they have been waiting for quite a while and still no takers.
Posted by malrob, Tuesday, 8 February 2011 10:41:40 PM
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My word, the denialists came out in force for this one. When will they give up? When the sea is over their heads, they are gasping for water, a meal, are expiring from heat exhaustion, freezing to death or are fighting each other for a small piece of whatever they need to survive, being blown away in a Cyclone, burnt in a bush fire
Or will they still be rationalizing that there is a logical reason for their predicament?
Posted by sarnian, Wednesday, 9 February 2011 8:24:56 AM
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Sniggid,

You said "Another alarmist rant from a left of left wing perspective".

I am sorry. Caring for humanity and the planet, whether the information proves correct or not, does not support any claim that Geoff Davies has provided just another leftwing rant.

You would be advised to read past environmental concerns by Henry Kissinger, who most would view as being on the right.
Posted by Chris Lewis, Wednesday, 9 February 2011 8:33:00 AM
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Here's a another factor to throw into the complexity of climate.The magnetic poles are shifting rapidly.40 km per yr.This has already reduced magnetic forces by 10%.This means our magnetic shield that reduces solar radiation is letting more energy reach the earth.Scientists are now saying that this shift in magnetic fields is causing severe electrical storms.

Another influence could be that of earthquakes and volcanoes.Imagine billions of tonnes of molten iron shifting beneath our floating continents.

They think that this could be a 1000 yr cycle whereby the magnetic poles swap over.

So to say CO2 is the major influence is foolish in the extreme.
Posted by Arjay, Wednesday, 9 February 2011 8:51:44 AM
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Curmudgeon-
Lots of theorising about Hansen's motivations, nothing about the substance of the paper.

malrob-
As I said to Alice: "For evidence that human emissions of CO2 are the main cause of present warming, see my post http://betternature.wordpress.com/2010/12/08/still-warming/ ." More directly, try http://climateprogress.org/2010/08/10/10-indicators-of-a-human-fingerprint-on-climate-change/print/ .

Alice-
The Hansen & Makiko paper doesn't depend on climate modelling at all. They are taking advantage of a natural experiment, conducted by the Earth, with all the complicated physics included and fully accurate - things like moisture levels and cloud formation. It allows the "climate sensitivity" to CO2 to be extracted. The result is that CO2 doubling from present levels will produce a temperature increase of 3 degrees, global average. Strangely enough that is about what climate modellers have been concluding. Without the CO2 feedback, the ice-age variations would have been only about 1.2 degrees.
Posted by Geoff Davies, Wednesday, 9 February 2011 9:24:26 AM
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Hasbeen:- Is at again making assertions without any evidence just sling off at a scientist and hope the mud sticks.

I must be hard for you to accept that all the skeptic climate scientist accept climate change is happening and that man is making a contribution, all they are arguing about is the percentage and it may be something else without being able to show anything.
Posted by PeterA, Wednesday, 9 February 2011 10:24:33 AM
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Geoff - I most certainly did talk about the substance of the paper. As I pointed out you cannot say it is wrong - that's impossible as its talking about a projection - just very weak because it is a projection which relies on several assumptions. You also have this problem in that there is some evidence that temperatures were a degree or two higher in medieval times and further back in the holocene, with no evidence that sea levels suddenly rose 5 metres.This business about temperatures now being as high as the MWP or the mid-Holocene maximum is a hard core global warmist thing.

None the less the paper has some scientific credibility in that it cannot be contradicted, but it remains very weak material. Take a step back and look at the paper for youself.

However, Hanson also has major political problems in that he is trying to insist on even tougher targets on emissions by relying on material that is much weaker than his earlier efforts with ice sheet break-up theories, which did not get the emission levels he wanted originally.

The global warming camp is becoming hysterical.
Posted by Curmudgeon, Wednesday, 9 February 2011 10:56:24 AM
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QUESTIONS

Thanks Geoff

1. "The Hansen & Makiko paper doesn't depend on climate modelling at all."

My modelling post was actually a response to your comment:"Weather is chaotic, but that doesn't make climate (the long-term average) chaotic."

I ask again: "Are you are claiming "long-term climate" is predictable? On what basis? Computer models? Established laws of climate change?"

In your post below you seem to endorse what "the climate modellers are concluding"?

"They are taking advantage of a natural experiment, conducted by the Earth, with all the complicated physics included and fully accurate - things like moisture levels and cloud formation. It allows the "climate sensitivity" to CO2 to be extracted. The result is that CO2 doubling from present levels will produce a temperature increase of 3 degrees, global average. Strangely enough that is about what climate modellers have been concluding. Without the CO2 feedback, the ice-age variations would have been only about 1.2 degrees."

2. Are you seriously suggesting that proxy data from the distant past (about "a natural experiment by the Earth") gives a complete and "fully accurate" reconstruction of a past climate with sufficient integrity to allow confident causal conclusions about "climate sensitivity" to carbon dioxide at that time?

Alice (in Warmerland)
Posted by Alice Thermopolis, Wednesday, 9 February 2011 10:59:41 AM
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Alice-
1. It is a characteristic of systems exhibiting "deterministic chaos" that they fluctuate chaotically about a mean that is fairly steady. Weather is chaotic, and its fluctuations are intrinsically unpredictable more than a week or so in advance, because the inevitable uncertainties in our knowledge of present conditions amplify exponentially with time in a chaotic system.

The slower evolution of the mean is not subject to this limitation. So, paradoxical as it might seem, climate (the slowly evolving mean) is more predictable than weather.

Can climate models usefully project future climate? Well, it's not easy, and there are some major uncertainties and difficulties, but they are not as hopeless as many denialists claim. For one thing, the projections have been fairly consistent over time, even though the early models were extremely simple in comparison with current ones. For another the real climate has developed broadly in accord with earlier projections, a basic fact that deniers overlook. FInally, the projections are consistent with estimates derived entirely independently, such as Hansen and Makiko's extraction of climate sensitivity from records of the past.

2. I'm not suggesting that the past climate can be reconstructed "fully accurately". I said the physics was in the real climate with full accuracy. Nor am I suggesting "confident casual conclusions". I am suggesting reasonable conclusions based on reconstructions whose uncertainties have been limited by a lot of past work on how to interpret proxies.

You see, real scientists openly discuss uncertainties and difficulties, and look for ways to reduce them. One way is to find alternative, independent ways to answer questions. If such independent approaches yield compatible conclusions, that builds confidence that the approaches are on the right track.

Too often, denialists take the discussions of uncertainties out of context and portray them as discrediting everything the scientists are doing. Then, if scientists reach a conclusion that the data seem to support, denialists say they must have fudged the data, or the analysis of the data, as our friend Curmudgeon seems to be doing.
Posted by Geoff Davies, Wednesday, 9 February 2011 2:01:27 PM
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UNCERTAINTY

Thanks Geoff

"You see, real scientists openly discuss uncertainties and difficulties, and look for ways to reduce them."

If only "real" climate scientists (and the IPCC) had taken your advice, openly discussing their uncertainties and difficulties transparently and honestly under rigorous public scrutiny rather than being, or appearing to be, complicit in (among other things) driving a UN "climate debt" agenda, perhaps there would be less doubt about their "storylines" today?

As one prominent climate scientist lamented recently: "apart from the issue of the actual logic used for reasoning, there is circularity in the argument that is endemic to whatever reasoning logic is used. Circular reasoning is a logical fallacy whereby the proposition to be proved is assumed in one of the premises.

http://judithcurry.com/2010/10/24/overconfidence-in-ipccs-detection-and-attribution-part-iii/

Another emphasised "the communication of climate projections, their uncertainties and caveats is crucial, and certainly merits more attention."

A critique of the IPCC’s treatment of uncertainty by the InterAcademy Council in October last year rightly noted (page 35, chapter 3) that: “assigning probabilities to imprecise statements is not an appropriate way to characterize uncertainty. If the confidence scale is used in this way, conclusions will likely be stated so vaguely as to make them impossible to refute, and therefore statements of ‘very high confidence’ will have little substantive value.”

By the way, is using an offensive term like "denialist" to label those who disagree with you either justified or helpful?

Alice (in Warmerland)
Posted by Alice Thermopolis, Wednesday, 9 February 2011 3:46:23 PM
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"By the way, is using an offensive term like "denialist" to label those who disagree with you either justified or helpful?"

Tis but a tool to help remind himself of his own superiority when dealing with anyone who disagrees .. hubris.
Posted by rpg, Wednesday, 9 February 2011 8:20:18 PM
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Alice-
I think the uncertainties have been readily available, and I don't understand why people bang on about this so much, unless it's just that they disagree with the assessment of uncertainty. It's odd to me that IPCC cops so much flak, because most climate scientists these days regard its statements as having been too conservative, particularly on potential sea level rise.

You can endlessly quote snippets out of context, but you always have to look at how statements are qualified in context to get a reasonable measure of the reliability that's attributed to conclusions.

You can be purist about how to present uncertainty about future events, but IPCC chose to use probability statements because they thought they would be the best way to communicate their assessments. That was their judgement, and others have other judgements.

If you want to be smart, or purist, then I can say you can't prove the sun will rise tomorrow. You can't put any probability on it. You can't even make an informal statement about reliability. Most people would say, however, that it's a reasonable projection, based on the millions of times it's happened before.
Posted by Geoff Davies, Thursday, 10 February 2011 8:26:14 AM
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Alice-
Regarding "denialist", I think those who dismiss a data set or finding without properly examining it, or who attack or disparage the messenger, or can only sneer and make contrary assertions, earn the description.

Perhaps also my patience isn't infinite on this web site. I invite you to count the number of insults, ad hominem slurs, disparaging remarks etc directed at me or James Hansen on this thread alone, and the amount of sarcasm and derision more generally, versus my one (I think) possibly unnecessary label. You can start with good old rpg's go at my motives in the post before this. I don't want your sympathy, I'm here by choice, but perhaps some of you could notice your own level of imperfection. Some here seem to be only interested in slanging, but still they have very thin skins.

On balance, Alice, you have conducted a not-unreasonable discussion. However your opening tone seemed to be one of derision, and you still sign off with the "in Warmerland" barb.

btw I don't debate in these threads because I think any posters are open to actual arguments and likely to change their minds. I do it for those (few?) who might be following, so they might see some balance in the discussions. Anyone still out there?
Posted by Geoff Davies, Thursday, 10 February 2011 8:30:49 AM
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Re Denialists.

There are many questions which remain controversial among scientists, but the existence of human-caused climate change is not one of them. Over 97% of publishing climatologists (Doran and Zimmerman, 2009), virtually 100% of peer-reviewed studies (Oreskes, 2004), and every scientific organization in the world (Logical Science, 2006) agree that humans are causing the Earth to warm. As Donald Kennedy, former editor-in-chief of the prestigious journal Science, says, “Consensus as strong as the one that has developed around this topic is rare in science.”
Posted by sarnian, Thursday, 10 February 2011 9:01:33 AM
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Oh and Alice, I notice you used the term "alarmist" in your very first post here. And the pervasive derision.

I take back some what I said about you being reasonable, and I note your thin skin.
Posted by Geoff Davies, Thursday, 10 February 2011 10:29:25 AM
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Thanks Geoff

Uncertainty and its treatment is surely critical here.

Many climate modellers find themselves in a CATCH-22 about modelling and just appeal to the Precautionary Principle.

"The other option is to communicate only what we are confident about. But being conservative (ie: not being wrong by not saying anything) may be dangerous in this context; once we are SURE about certain THREATS, IT MAY BE TOO LATE TO ACT." [p4660, Phil.Trans.R.Soc. A (2008)

How convenient. "Climate model projections are admittedly an issue"; but, "they are unlikely to be the limiting factor that prevents us from making a decision and acting on, rather than talking about, the climate change problem."

Translation: We don't know whether there really is a 'climate change problem' (and may never know?), but if (let's assume) there is one and if humankind does not act now, it will be TOO LATE. Catch-22. How do we know it will be "too late", if we really don't know whether there is a CC problem, and so on?

As Judith Curry lamented last year while reflecting on uncertainty (from inside the modeller tent):"there is circularity (in the argument) that is endemic to whatever reasoning logic is used".

As for my use of the term "alarmist", how else should one describe your closing comparison?

"After the extreme weather of Black Saturday, Australia added the “Catastrophic” category of bush fire danger above the previous highest “Extreme” category.

The danger from global warming may have moved from “Extreme” to “Catastrophic”."

Do you really believe it is legitimate to use such a (local/global/unrelated) comparision - and the word "catastrophic" - given our present state of knowledge about this controversial issue?

[You are not suggesting the "extreme weather" that caused the Victorian bushfires was a direct result of "climate change"/local warming/etc, especially after the "extreme weather" of the wet summer there this year?]

If you do, you run the risk of attracting not only "pervasive derision", but also being grouped with the countless "the-end-is-nigh"/"Godot-is-coming" folk down the centuries who (so far, at least) turned out to be false prophets.

Alice (in Warmerland)
Posted by Alice Thermopolis, Thursday, 10 February 2011 12:10:57 PM
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Alice-

Scientists (including me) who appeal to the precautionary principle do so as ordinary people, not as part of their science. It is not a scientific conclusion, just something that seems a sensible way of proceeding, like buying insurance, or not getting on a plane that has a 10% chance of crashing.

If you say scientists should stick to science, well I don't agree. We are people too, with as much right as anyone else to argue for a policy.

On models, the case does not depend just on models, Alice, that's one of the main points of this article. And the models *do* have some level of reliability, despite your repeated claims to the contrary.

On "alarmist": if the news is alarming, that doesn't make the messenger an alarmist. Simple distinction Alice. An alarmist is someone who raises the alarm when there is no relevant threat. I (and many others) certainly think there is a relevant, alarming threat. The consequences of global warming could indeed be "catastrophic". That is the implication of the bushfire warning: it is a warning of potential catastrophe. Only with global warming the potential is for *global* catastrophe.

As I have said many times on threads and in articles on this site, the resistance to reducing our greenhouse gas emissions only makes sense if it would be a big burden on our society. But it wouldn't. Even mainstream economists are now agreeing that the net cost to the economy would be small, less than 1% reduction in GDP growth. It's not a large insurance premium to pay. Some industries would phase out and others would grow, but we've had plenty of such "restructuring" over the past 30 years. So why all the kicking and screaming?
Posted by Geoff Davies, Thursday, 10 February 2011 8:46:52 PM
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Thanks Geoff

"Scientists (including me) who appeal to the precautionary principle do so as ordinary people, not as part of their science. It is NOT a scientific conclusion, just something that seems a sensible way of proceeding, like buying insurance, or not getting on a plane that has a 10% chance of crashing.

If you say scientists should stick to science, well I don't agree. We are people too, with as much right as anyone else to argue for a policy."

If climate (and other)scientists also want to be activists arguing for a policy, if they want to use the so-called precautionary "principle" to justify their views, that's fine.

Unlike you, however, quite a few folk do so while either hiding behind a public cloak of being disinterested seekers of truth. So-called 'facts' are all too often "theory-laden" and contaminated by confirmation bias, "projections" morph into "predictions", etc.

Now you, a physicist, are using "mainstream economists" to justify imposing a 'carbon (dioxide) price'/tax/ETS on Australia based on some kind of "risk-management" argument.

Why all the kicking and screaming, Geoff? Many believe this is unjustified, based on hard empirical evidence - not hypotheses, models, proxy datasets, circular arguments, and so on.

As for mainstream economists, their "cost/benefit" assessments of the future are just as, perhaps even more, debatable and controversial than those of climate scientists.

As one economist said recently: "In economic (climate) policy we are necessarily dealing with the future and in this we are all blind. I suppose economic theory is a bit like the blind man's stick, of some but limited use, particularly when crossing a busy road and the path of economic activity is a busy road indeed. Too much reliance should not be placed on it."

Alice (in Warmerland)
Posted by Alice Thermopolis, Friday, 11 February 2011 12:10:18 PM
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Alice-

Just to be clear, I'm no fan of mainstream economics. I said "even" mainstream economists.

The better approach is to look at the many things that have already been done to reduce emissions dramatically, and work on moving those out to everyone. It's a very cost-effective investment. The big advantage, when done the right way, is that you also reduce the many other assaults on the planet we depend totally on. If global warming doesn't get us, several other crises are brewing that will.

Yes, I know, you don't believe such things, you label them Malthusian or whatever, but the symptoms of distress are all around us and in the news virtually every day.

I think the underlying factor is that people who refuse to take *any* warnings seriously just can't face a (modest) change in their conception of the world. It's just too scary to step out of their comfort zone. Sorry, there have been plenty of opinions here on what motivates me, so that's my opinion on what motivates many "sceptics", for what it's worth.

If you think your arguments are backed by "hard empirical evidence - not hypotheses, models, proxy datasets, and so on", then there's not much more to be said. You simply reveal your lack of appreciation of the assumptions and biases behind the interpretations you prefer.

I think this exchange has about run its course.
Posted by Geoff Davies, Friday, 11 February 2011 1:01:46 PM
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I don't have a problem with global warming or what else you call it. It's great to see things changing away from carbon based manufacturing.
Electric cars are coming along nicely.
It is a thorn in the side of people that are pushing their own barrow.
Move away from a carbon tax and it won't hurt you.
Posted by a597, Friday, 11 February 2011 2:54:01 PM
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Geoff

You have been generous with your time. Thank you.

"The big advantage, when done the right way, is that you also reduce the many other assaults on the planet we depend totally on. If global warming doesn't get us, several other crises are brewing that will.

Yes, I know, you don't believe such things, you label them Malthusian or whatever, but the symptoms of distress are all around us and in the news virtually every day."

As for me, I try not to justify belief in one potential "crisis" (CC, AGW, ACC, EWEs), by mixing it into a stew of "other crises".

That said, and contrary to your suggestion above, the term "Malthusian" for me is not pejorative at all. Ultimately, his Principle of Population - or a recasting of it - may be closer to the truth than the perspectives of his many critics.

One number known with reasonable accuracy in the global population. While it took a million years for humankind to reach 1,000 million two centuries ago, sometime this year there will be 7,000 million people on the planet.

"Non quantitas, sed qualitas!"

Alice (in Malthusiana)
Posted by Alice Thermopolis, Friday, 11 February 2011 7:15:53 PM
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Thanks Alice, and I'm glad we can agree on population and its several consequences.
Posted by Geoff Davies, Saturday, 12 February 2011 2:26:08 PM
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