Global Warming backdown

[Keepitsimple]

Interesting article on the IPCC written by Mike Hulme and Martin Mahony, School of Environmental Sciences, University of East Anglia. As with many so-called sceptics - I like the term "Truethers" better, I am concerned with how the IPCC deals with areas of uncertainty - how they are explained - and what level of visibility they are given. If you have the patience, the entire article is worth reading, but I've included the introduction to the area of "Uncertainty" below. I've bolded a particular area that has been a bone of contention for Sceptics (Truethers).

Consensus and Uncertainty

Since its origins, the IPCC has been open and explicit about seeking to generate a ‘scientific consensus’ around climate change and especially about the role of humans in climate change. Yet this has been a source of both strength and vulnerability for the IPCC. Understanding consensus as a process of ‘truth creation’ (or the more nuanced ‘knowledge production’) which marginalises dissenting voices – as has frequently been portrayed by some of the IPCC’s critics (see Edwards & Schneider, 2001; Petersen, 2010) – does not do justice to the process.

Consensus-building in fact serves several different goals. As Horst and Irwin (2010) have explained, seeking consensus can be as much about building a community identity – what Haas (1992) refers to as an epistemic community – as it is about seeking the ‘truth’. Equally, as Yearley (2009) explains, IPCC consensus-making is an exercise in collective judgement about subjective (or Bayesian) likelihoods in areas of uncertain knowledge. Consensus-making in the IPCC has been largely driven by the desire to communicate climate science coherently to a wide spectrum of policy users – ‘to construct knowledge’ (Weingart, 1999) - but in so doing communicating uncertainties have been down-played (van der Sluijs, 1998). As Oppenheimer et al. (2007: 1506) remark: “The establishment of consensus by the IPCC is no longer as critical to governments as [is] a full exploration of uncertainty.”

Without a careful explanation about what it means, this drive for consensus can leave the IPCC vulnerable to outside criticism. Claims such as ‘2,500 of the world’s leading scientists have reached a consensus that human activities are having a significant influence on the climate’ are disingenuous. That particular consensus judgement, as are many others in the IPCC reports, is reached by only a few dozen experts in the specific field of detection and attribution studies; other IPCC authors are experts in other fields. But consensus-making can also lead to criticism for being too conservative, as Hansen (2007) has most visibly argued. Was the IPCC AR4 too conservative in reaching its consensus about future sea-level rise? Many glaciologists and oceanographers think they were (Kerr, 2007; Rahmstorf, 2010), leading to what Hansen attacks as ‘scientific reticence’. Solomon et al. (2008) offer a robust defence, stating that far from reaching a premature consensus, the AR4 report stated that in fact no consensus could be reached on the magnitude of the possible fast ice-sheet melt processes that some fear could lead to 1 or 2 metres of sea-level rise this century. Hence these processes were not included in the quantitative estimates.

This leads onto the question of how uncertainty more generally has been treated across the various IPCC Working Groups.

.........................continued

Link: http://www.probeinternational.org/Hulme-Mahony-PiPG%5B1%5D.pdf

[Michael Hardner]

KiS - do NOT use the term 'truther' as it has other implications (911 conspiracy stuff, toxic, stay away).

Also this article doesn't differentiate between working groups in the IPCC.

[Keepitsimple]

KiS - do NOT use the term 'truther' as it has other implications (911 conspiracy stuff, toxic, stay away).

Also this article doesn't differentiate between working groups in the IPCC.

You're probably right....I guess I got a little grumpy this morning. The article is a general one about the entire IPCC process. You'd have to read it from the beginning to get an idea of it's scope but it's an umbrella article. You'll find references to how different working groups do things differently.....kind of on their own. The article does not appear to aim to be critical for or against any particular working group - it seems to just tell it like it is with regards to the process - and the pitfalls of what has evolved in some areas.....as you can surmise by the authors - who work for or in and around the CRU. I'd encourage you to start at the beginning and read through it - it's fascinating and offers a variety of published pros and cons of many areas of IPCC's processes and governance.

Edited June 18, 2010 by Keepitsimple

[waldo]

Interesting article on the IPCC written by Mike Hulme and Martin Mahony, School of Environmental Sciences, University of East Anglia. As with many so-called sceptics - I like the term "Truethers" better, I am concerned with how the IPCC deals with areas of uncertainty - how they are explained - and what level of visibility they are given. If you have the patience, the entire article is worth reading, but I've included the introduction to the area of "Uncertainty" below. I've bolded a particular area that has been a bone of contention for Sceptics (Truethers).

Truethers!!!

of course, in your lengthy and ongoing diatribe against the IPCC, should we be surprised you haven't a clue about how the IPCC works in preparing reports. When the lead authors can't realize a consensus in terms of the available science, within that particular area of the reporting process, differing views are explained. This is the norm... as it exists and appears innumerable times throughout the various IPCC reports. If you've actually taken the time to read one of the reports, you would readily recognize this... but, of course, that would require you to actually... read an IPCC report.

of course, denialtown has worked itself into a frenzy over that exact snippet you've bold highlighted within your linked article... as the good parrot you are. I trust the following clarification from Hulme won't upset your/denialtown's glee in having taken liberty with his article/writings... Correcting and Clarifying Hulme and Mahony on the IPCC Consensus

Three things should be clear from this. First, I did not say the ‘IPCC misleads’ anyone – it is claims that are made by other commentators, such as the caricatured claim I offer in the paper, that have the potential to mislead. Second, they have a potential to mislead if they give the impression that every statement in IPCC reports is ‘signed off’ by every IPCC author and reviewer. Patently they are not, and cannot. Third, it is the chapter lead authors – say 10 to 20 experts - on detection and attribution who craft the sentence about detection and attribution, which is then scrutinised and vetted by reviewers and government officials. Similarly, statements about what may happen to the meridional overturning circulation (MOC) of the ocean are crafted by those expert in ocean science, statements about future sea-level rise by sea-level experts, and so on.

The point of this bit of our article was to draw attention to the need for a more nuanced understanding of what an IPCC ‘consensus’ is – as I say: “Without a careful explanation about what it means, this drive for consensus can leave the IPCC vulnerable to outside criticism.” The IPCC consensus does not mean – clearly cannot possibly mean – that every scientist involved in the IPCC process agrees with every single statement in the IPCC! Some scientists involved in the IPCC did not agree with the IPCC’s projections of future sea-level. Giving the impression that the IPCC consensus means everyone agrees with everyone else – as I think some well-meaning but uninformed commentaries do (or have a tendency to do) – is unhelpful; it doesn’t reflect the uncertain, exploratory and sometimes contested nature of scientific knowledge.

[waldo]

You are speaking in the plural when you say "scientists' ", Michael. I don't think anyone is suggesting "they" submit incorrect papers. If anything Waldo throughout this thread tells us that any differing scientist has been bought by big oil or is incompetent.

Pliny, why must bullshit artists, like yourself, attribute false claims to individuals you don't agree with... oh wait... that's what bullshit artists do. No problem, Pliny... carry on.

In actual fact there are only a few scientists with political connections/influence being scrutinized.

Pliny, how do you rationalize this latest acceptance of yours that only a "few" scientists are being scrutinized? You've certainly gone hog-wild with concern over scientists politicizing science... all your past blustering for what you now express relates to only a "few" scientists. C'mon, Pliny - learn to scale your fake outrage - hey?

[TimG]

When the lead authors can't realize a consensus in terms of the available science, within that particular area of the reporting process, differing views are explained.

The trouble is the various CAGW advocates oversell what the the IPCC report actually says. The case of sea level rise is perhaps the best example where there was no consensus yet that did not stop Gore from implying there would be a 7 meter sealevel rise in the near future. I think the debate would be a lot less shrill if CAGW advocates would dispense with claims of certainty that are not supported by the science.

[waldo]

Per the e-mails - Ignoring data that disagrees with the desired thesis is evidence of political contamination...and further ignoring it - a la Waldo, is akin to religious devotion.

as always, you are encouraged to step out of the shadows and actually back up your continued assertions concerning data. You're crafty though... I see you've backed off of your previous claims concerning... deleted data, or manipulated data. Now, it's "ignoring data"! Might you surprise us and actually step forward with something, with anything, to substantiate your claims of... ignoring data! C'mon, Pliny - step up. Just once.

Yeah....it is going down Waldo....sorry....nothing I can do.

sure Pliny - your mindless talk is cheap. Let's see you put your global cooling temperature predictions up for scrutiny, context, etc.

[waldo]

When the lead authors can't realize a consensus in terms of the available science, within that particular area of the reporting process, differing views are explained.

The trouble is the various CAGW advocates oversell what the the IPCC report actually says. The case of sea level rise is perhaps the best example where there was no consensus...

yes, sea level rise is a very good example. One where IPCC projections fell conservatively short... one of the reasons being the IPCC didn't include the full effects of ice-sheet flow melting (because of unknowns). Most certainly, when ice-sheet flow melting is included, the conservative IPCC sea level rise projections are significantly increased. In regards that lack of consensus, several IPCC lead authors unsuccessfully argued for inclusion of ice-sheet flow melting.

[TimG]

In regards that lack of consensus, several IPCC lead authors unsuccessfully argued for inclusion of ice-sheet flow melting.

And they failed because others did not feel their claims were as strong as they believed. But that did not stop those authors from running around and misrepresenting what the IPCC consensus said which is the real problem. If CAGW advocates want to wave the IPCC document as a scientific authority then they have to respect what that authority says - even if what it says casts doubt on the catastrophe narrative. Edited June 21, 2010 by TimG

[waldo]

And around and around we go....because those same graphs when looked at in detail for even the last century show very wide swings in temperature of 20-30 year durations that show that natural variability appears to overwhelm the presence of CO2.......and how can some/many scientists predict the next 20-30 years might have no warming or even cooling - if in fact CO2 is the major driver - and it's still rising?

absolute rubbish! I've chided you, repeatedly, over your continued references to a "30 year" temperature cycle... that I've included attachment to Don Easterbrook while doing so, obviously, has you gun shy. Easterbrook's 30-year temperature cycle nonsense has been soundly debunked, many times over. Of course, that doesn't prevent you from continuing to make reference to it. And, of course, although you'll make a generic reference to it (to the "30 year" temperature cycle), the fact you won't actually qualify it, the fact you won't even attribute it to Easterbrook is simply another telling point in your game/charade.

c'mon, Simple... substantiate your natural variability influence... step up and explain the basis for your repeated and citation-less claims concerning a 30 year temperature cycle. C'mon, Simple... give Easterbrook his just recognition!

[waldo]

yes, sea level rise is a very good example. One where IPCC projections fell conservatively short... one of the reasons being the IPCC didn't include the full effects of ice-sheet flow melting (because of unknowns). Most certainly, when ice-sheet flow melting is included, the conservative IPCC sea level rise projections are significantly increased. In regards that lack of consensus, several IPCC lead authors unsuccessfully argued for inclusion of ice-sheet flow melting.

And they failed because others did not feel their claims were as strong as they believed. But that did not stop those authors from running around and misrepresenting what the IPCC consensus said which is the real problem. If CAGW advocates want to wave the IPCC document as a scientific authority then they have to respect what that authority says - even if what it says casts doubt on the catastrophe narrative.

no - the authors were unsuccessful because of what were, at that time, the unknowns related to ice-sheet flow melting. The prevailing argument was, with full qualification, to not include ice-sheet melting.

I can't respond to your other generalizations concerning your statement:

- "that did not stop those authors from running around and misrepresenting what the IPCC consensus said which is the real problem". Which authors? What was misrepresented, how was it misrepresented, where was it misrepresented?

[waldo]

That is precisely the only stake that sceptics have ever had in the game......all the rest is just noise from the alarmists. There might be a fringe group that doesn't believe in Climate Change or doesn't believe that this phase of Climate Change is a warming one......but I have not seen any of those on this board. It's simply a question of how much is CO2 contributing to the warming over and above natural variability and of that, how much is human induced. Remember, the science does not prove that CO2 causes the "excess warming" that seems to prevail - it's just that they can't find anything else to account for it.....and so by a process of elimination, some scientists have settled on CO2 as being a major driver - even though there are recent and older cyclic occasions where natural variability has overwhelmed the presence of CO2 and produced cooler times or times that were equally as warm.

continued Simple ton nonsense. Don't hesitate to step forward and assert your claims for natural variability being the cause of the relatively recent global warming. Oh... that's right... you can't. Carry on.

[waldo]

Over that period of time 2.5F or 1.4C is inconsequential.

again, that trend offering, as highlighted, was simply in response to your numbing mindless cut/paste exercise... it was also categorized as simply a localized result - nothing more. It's quite telling that you're so ready to dismiss the trend result increase... regardless... of how it (with all the caveats attached) actually compares to recognized global surface temperature increases during the 20th century. Obviously, you haven't a reference clue to recognize, understand and appreciate how much warming, on a global scale, that trend result could equate to.

[waldo]

ah yes! One of Shady's favoured go-to British tabloid "journalists", Jonathan Leake from the Sunday Times, has finally issued the retraction over his so-called Amazongate fabrication. Of course, the damage was already done - the standard denier cares not of facts... the intent is simply to cast doubt and uncertainty. Into the mainstream went Leake's fabrication, but meanwhile, the Sunday Times retraction sits behind an online paywall!

Leakegate: A retraction

another day... another Shady go-to of his favourite British tabloid "journalist", "

Jonathan Leake

"... looks like the Shady "intellectual dishonesty" continues.

even outside the climate change related debate, we recently experienced firsthand the way the British tabloid press handled coverage of the Vancouver Olympics... it's no surprise Shady would find solace in linking to and parroting anything - anything - the British tabloids print. Shady has no ethics - no morality - no honesty.

British Newspapers Make Things Up

the backlash against the British tabloids is building; interested parties are collectively gathering the evidence against the British tabloid "journalists"... be they

David Rose

,

Piers Akerman

... or Shady's favourite -

Jonathan Leake

one of those bloggers, Tim Lambert (amongst others), has recently started to catalogue the fabrications of Jonathan Leake. If you're not familiar with Tim Lambert, he's a legitimate Australian scientist, recently of note involved in demolishing the denier poster-boy Monckton during a much touted/publicized debate in Australia.

The dishonesty, the lies, the fabrication of Jonathan Leake... Shady's most favoured go-to British tabloid journalist:

- Shady's most recent display of his "intellectual dishonesty"... concerning Jonathan Leake's fabrication concerning tropical cyclones (typhoons and hurricanes):

Leakegate + The Australian's War on Science 46

- the original

Leakegate

(re: Amazon forest)

-

Leakegate scandal grows

-

Leakegate scandal gets bigger

-

Leakegate: the case for fraud

-

Journalismgate

-

Leakegate: Jonathan Leake caught misrepresenting another scientist

-

Leakegate: Leake verballed Richard Dawkins

-

Leakegate: On stovepiping and plagiarism

-

Leakegate: Yes, Leake was responsible for that bogus story about the carbon footprint of Google

-

Leakegate: How Jonathan Leake concocted 'Africagate'

-

Leakegate: "not based on any research"

[TimG]

no - the authors were unsuccessful because of what were, at that time, the unknowns related to ice-sheet flow melting. The prevailing argument was, with full qualification, to not include ice-sheet melting.

The IPCC report does not support your claims:

http://www.ipcc.ch/publications_and_data/ar4/wg1/en/ch10s10-6-5.html

Figure 10.33. Projections and uncertainties (5 to 95% ranges) of global average sea level rise and its components in 2090 to 2099 (relative to 1980 to 1999) for the six SRES marker scenarios. The projected sea level rise assumes that the part of the present-day ice sheet mass imbalance that is due to recent ice flow acceleration will persist unchanged. It does not include the contribution shown from scaled-up ice sheet discharge, which is an alternative possibility. It is also possible that the present imbalance might be transient, in which case the projected sea level rise is reduced by 0.02 m. It must be emphasized that we cannot assess the likelihood of any of these three alternatives, which are presented as illustrative. The state of understanding prevents a best estimate from being made.

This statement lists 3 hypotheses: the current ice melt continues, the ice melt will accelerate, the ice melt will stop. They claim they cannot assess the likelihood of each because of the uncertainty. There is nothing that supports your assertion that rise was knowingly underestimated because of unknowns. On this point, it appears the IPCC got it right by correctly reflecting the full range of scientific opinion at the time. Edited June 21, 2010 by TimG

[Keepitsimple]

I have Waldo on IGNORE so I don't know what he's spewing.....but it appears our IPCC shill has blown a gasket.

Edited June 21, 2010 by Keepitsimple

[Pliny]

I have Waldo on IGNORE so I don't know what he's spewing.....but it appears our IPCC shill has blown a gasket.

After a three or four day hiatus he is just playing catch up. With the usual,every scientist that utters blasphemy against the scriptures is in the evil corporate hands of big oil or his credentials are not valid. Does he not realize how he sullies the field?

Of course, all of his sources are credible and their work of the utmost scientific purity.

[waldo]

The IPCC report does not support your claims:

http://www.ipcc.ch/publications_and_data/ar4/wg1/en/ch10s10-6-5.html

This statement lists 3 hypotheses: the current ice melt continues, the ice melt will accelerate, the ice melt will stop. They claim they cannot assess the likelihood of each because of the uncertainty. There is nothing that supports your assertion that rise was knowingly underestimated because of unknowns. On this point, it appears the IPCC got it right by correctly reflecting the full range of scientific opinion at the time.

no - the AR4 report most certainly does support my statement... that you've carried forward and state as, "uncertainty... knowingly underestimated because of unknowns"; specifically:

Further accelerations in ice flow of the kind recently observed in some Greenland outlet glaciers and West Antarctic ice streams could increase the ice sheet contributions substantially, but quantitative projections cannot be made with confidence (see

Section 10.6.4.2 (

Dynamics

)

).

so... yes... (further accelerations in ice flow) were not included because quantitative projections cannot be made with confidence - where related unknowns/uncertainties are detailed within the referenced section 10.6.4.2 - Dynamics). And yes, in this example, the IPCC AR4 report, most certainly, is viewed as having provided most conservative projections for sea level rise.

[waldo]

After a three or four day hiatus he is just playing catch up. With the usual,every scientist that utters blasphemy against the scriptures is in the evil corporate hands of big oil or his credentials are not valid. Does he not realize how he sullies the field?

Of course, all of his sources are credible and their work of the utmost scientific purity.

Pliny, you've already read my response to your assertion... why repeat it... unless you, once again, want to be labeled a bullshit artist?

You are speaking in the plural when you say "scientists' ", Michael. I don't think anyone is suggesting "they" submit incorrect papers. If anything Waldo throughout this thread tells us that any differing scientist has been bought by big oil or is incompetent.

Pliny, why must bullshit artists, like yourself, attribute false claims to individuals you don't agree with... oh wait... that's what bullshit artists do. No problem, Pliny... carry on.

[waldo]

I have Waldo on IGNORE so I don't know what he's spewing.....but it appears our IPCC shill has blown a gasket.

of course, you're reading all my posts Simple - thanks again for the chance to highlight your ridiculous claims concerning a 30-year temperature cycle... you know, the Don Easterbrook originated folly that you so continue to generically reference... without qualification... and without giving Easterbrook his just recognition!

I've chided you, repeatedly, over your continued references to a "30 year" temperature cycle... that I've included attachment to Don Easterbrook while doing so, obviously, has you gun shy. Easterbrook's 30-year temperature cycle nonsense has been soundly debunked, many times over. Of course, that doesn't prevent you from continuing to make reference to it. And, of course, although you'll make a generic reference to it (to the "30 year" temperature cycle), the fact you won't actually qualify it, the fact you won't even attribute it to Easterbrook is simply another telling point in your game/charade.

c'mon, Simple... substantiate your natural variability influence... step up and explain the basis for your repeated and citation-less claims concerning a 30 year temperature cycle. C'mon, Simple... give Easterbrook his just recognition!

[TimG]

(further accelerations in ice flow) were not included because quantitative projections cannot be made with confidence

So? Please read the caption from the figure with the actual projections:

The projected sea level rise assumes that the part of the present-day ice sheet mass imbalance that is due to recent ice flow acceleration will persist unchanged. It does not include the contribution shown from scaled-up ice sheet discharge, which is an alternative possibility. It is also possible that the present imbalance might be transient, in which case the projected sea level rise is reduced by 0.02m. It must be emphasized that we cannot assess the likelihood of any of these three alternatives, which are presented as illustrative.

The language is pretty clear to me. There are 3 (three) views on the future behavior of ice. Only 1 (one) of those views claims that ice sheet melt will contribute to significant sea level rise. So while the scientists promoting the CAGW narrative likely believe they are right their position is not the position of the IPCC and they cannot reasonably claim that their view was left out if the IPCC report because of a technicality. It was left out because their were other scientists who felt their claims were not supported by the evidence.

Edited June 21, 2010 by TimG

[jbg]

So? Please read the caption from the figure with the actual projections:

Waldo has serious objections when I include actual historical temperature data. As if global warming wasn't somehow connected to temperatures.

[waldo]

no - the AR4 report most certainly does support my statement... that you've carried forward and state as, "uncertainty... knowingly underestimated because of unknowns"; specifically:

Further accelerations in ice flow of the kind recently observed in some Greenland outlet glaciers and West Antarctic ice streams could increase the ice sheet contributions substantially, but quantitative projections cannot be made with confidence (see

Section 10.6.4.2 (

Dynamics

)

).

so... yes... (further accelerations in ice flow) were not included because quantitative projections cannot be made with confidence - where related unknowns/uncertainties are detailed within the referenced section 10.6.4.2 - Dynamics). And yes, in this example, the IPCC AR4 report, most certainly, is viewed as having provided most conservative projections for sea level rise.

So? Please read the caption from the figure with the actual projections:

The language is pretty clear to me. There are 3 (three) views on the future behavior of ice. Only 1 (one) of those views claims that ice sheet melt will contribute to significant sea level rise. So while the scientists promoting the CAGW narrative likely believe they are right their position is not the position of the IPCC and they cannot reasonably claim that their view was left out if the IPCC report because of a technicality. It was left out because their were other scientists who felt their claims were not supported by the evidence.

technicality? Who said anything about a, "technicality"? I'm still not entirely clear what you're even arguing about/for... as I stated, in regards to ice-sheet flow melting, there wasn't a consensus realized within the grouping of lead authors; accordingly, the report only included conservative estimates on ice-sheet flow melting. I've quoted the exact statement in the report that supports this, including the linked report reference that qualifies the unknowns/uncertainties that resulted in the lack of consensus... that resulted in the conservative projections.

if you're attempting to make something over the fact certain scientists believe the 2007 AR4 report provided a conservative projection in regards ice-sheet flow melting, it's an interesting slant - one we don't regularly (if ever) read around here. The MLW usual denier suspects all attempt to denigrate the IPCC, claiming it exaggerated - or fabricated - the science at the point of report publication. I can't recall anyone making the case for the IPCC having been, as you appear to be, (properly) conservative in any of it's projections.

for certain scientists, in regard sea-level rise, the lack of consensus within the report carries forward... as does the science. The real issue is what does the prevailing science state concerning sea-level rise. The AR4 report simply mirrors the science to the point of publication... AR5 is scheduled to be released in 2015. Surely you can't be advocating for negating an acknowledgment to those scientists who believe that the 2007 AR4 report projections are too conservative... simply because a previously published report authors chose to not include something based on stated unknowns/uncertainty.

When the lead authors can't realize a consensus in terms of the available science, within that particular area of the reporting process, differing views are explained.

The trouble is the various CAGW advocates oversell what the the IPCC report actually says. The case of sea level rise is perhaps the best example where there was no consensus...

yes, sea level rise is a very good example. One where IPCC projections fell conservatively short... one of the reasons being the IPCC didn't include the full effects of ice-sheet flow melting (because of unknowns). Most certainly, when ice-sheet flow melting is included, the conservative IPCC sea level rise projections are significantly increased. In regards that lack of consensus, several IPCC lead authors unsuccessfully argued for inclusion of ice-sheet flow melting.

[waldo]

Waldo has serious objections when I include actual historical temperature data. As if global warming wasn't somehow connected to temperatures.

no - I had concerns over your numbing and futile raw data cut-paste exercises. You actually thought you were providing something of substance... unfortunately, no one has your eyeballing prowess of that endless stream of raw data you put forward. Equally, it was most unfortunate you didn't bother providing any qualification as to what you managed to eyeball within that raw data... in a mindless exercise, you simply cut-pasted reams of raw data... because you could!

as for what AGW is connected to... it most certainly isn't connected to your, without qualification, numbing, futile and mindless eyeballing of raw data.

[TimG]

I can't recall anyone making the case for the IPCC having been, as you appear to be, (properly) conservative in any of it's projections.

What I am saying is the IPCC captured the full range of scientific views on this point and acknowledged the uncertainty. In this case the full range of views includes the view that recent increases in ice melt are transient and that there will be no net SLR contribution from ice sheets over the next 100 years.

When you make the claim that the IPCC was 'conservative' you seek to imply that the actual SLR is likely to be much larger because the ice sheet melt was 'left out'. That is not a reasonable reading of the report because the report also says that the SLR could end up being smaller because the ice sheets are more stable than the CAWG advocates believe. The correct reading of the report is we have no idea how ice sheets will affect SLR.

Surely you can't be advocating for negating an acknowledgment to those scientists who believe that the 2007 AR4 report projections are too conservative

Not at all. I am just pointing out that they are not the 'IPCC consensus view' should not be represented as the consensus view. We will have to wait until 2014 to see if that changes. Edited June 21, 2010 by TimG