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All IPCC definitions taken from Climate Change 2007: The Physical Science Basis. Working Group I Contribution to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change, Annex I, Glossary, pp. 941-954. Cambridge University Press.

"How do we know more CO2 is causing warming?"

alan_marshall at 20:13 PM on 8 May 2011

Q and A with Dr Haydn Washington, co-author of Climate Change Denial
Michael Sweet @ 10 I welcome this timely book by John and Hayden, and look forward to reading it. In relation to the argument you put, I agree that it helps explain why some Christians are apathetic about climate change. However, I don’t believe they are unreachable. Another new book, co-authored by a climate scientist and an evangelical Christian, respectfully puts the case for climate action in the context of a Christian world-view: Kathrine Hayhoe aned Andrew Farley, A Climate For Change: global warming facts for faith-based decisions, Faith Words, New York 2011 Suppose for a moment that the Christians you refer to are right and that the creator comes back to wrap up the show 25, 50, 100 or 200 years from now (before we totally destroy ourselves). Does that mean that we should go on trashing his creation until he returns? I put it to you that displeases him. It may even be, if you see bible prophecy the way I do, that some of the calamities prophesied are consequences of our environmental vandalism. Two of my own publications that may interest you are a Bible study guide Christians and the Environment, and my paper Shaping a Sustainable World, published in the Notre Dame Journal of Law, Ethics and Public Policy, which argues the need for climate action from a Judeo-Christian perspective.

martinrkellogg at 18:12 PM on 8 May 2011

Lindzen Illusion #5: Internal Variability
A better link for Purkey and Johnson (2010) -- "Warming of Global abyssal and deep Southern Ocean waters between the 1990s and 2000s: Contributions to global heat and sea level rise budgets*" -- should be here (if I copied it correctly), as no payment is required to see the full article. Otherwise, it can be accessed quickly at this location.

Response:

[DB] Fixed URLs. Posting tips can be found here.

owl905 at 15:46 PM on 8 May 2011

Lindzen Illusion #5: Internal Variability
dorlomin wrote:- "Lindzen is a genuinely great atmospheric physicist." No he isn't. If his last name wasn't MIT he wouldn't get the time of day from a watchmaker. His iris, his cooling trend since (latest date goes here), his 'missing hotspot' and tropics focus, the 'clouds' problem ... it's one 'butwaddabout' after another. His own explanations don't net out to rigorous science; they come across like 'nya nya can't make me' dodges.

schitzree at 15:22 PM on 8 May 2011

Q and A with Dr Haydn Washington, co-author of Climate Change Denial
An Interesting looking book. It should fit in well on my shelf next to 'Hubbert's Peak', 'The Boswick Report' & 'None Dare Call It Treason'.

sgmuller at 13:33 PM on 8 May 2011

Lindzen Illusion #5: Internal Variability
Funglestrumpet - They get away with it because organisations like Murdoch's News Corp are actively following an anit-AGW agenda. They use what Garnaut has described as a "curious kind of balance - a balance of words rather than scientific opinion". They conduct the debate in political terms rather than scientific terms. This means that for every black there must be a white, there can be no shades of grey. For every left there must be a right, you get the idea. The rest of the media follow this same method. This means that if right wingers such as Howard and Bush support the skeptics then it must follow that AGW must be a left wing theory. You just cannot have a scientific theory that is independent of politics. Even organisations like the ABC feel that they must provide equal time to "the other side". This is how the 3% skeptics leverage there media presence up to 50% or more. I started to watch a global warming doco on SBS a few nights ago. It followed a very simplistic formula of one opinion from that side, one opinion from this side. They had Christy as the token skeptic, possibly because he has a big moustache and looks like a cool scientist. They gave him 3 minutes then the other side 3 minutes then they started to talk about electric cars for no apparent reason, maybe they were sponsored by Nissan. Anyway that's where I turned it off. We know that if you were to present one opinion from each side then you could easily have 1000 opinions, 970 of which would be pro-AGW. But the mass media, especially television can't work with that, in the mind of a producer of a TV doco there can only be 2 sides, so they find two opposing views, present them as though that was all there was, then walk away smugly satisfied that they have presented a show that was balanced and unbiased. I've got no idea how to break through this kind of simplistic dumbing down of the debate. Given that Channel Ten has now given Bolt his own TV show, I don't believe that any mass media organisation, whether its TV or newspapers, will ever provide an honest comprehensive coverage of the global warming debate.

EliRabett at 12:34 PM on 8 May 2011

Frauenfeld, Knappenberger, and Michaels 2011: Obsolescence by Design?
Tom, Eli got a copy of the data for the graph by writing to Frauenfeld.

David Horton at 11:30 AM on 8 May 2011

Q and A with Dr Haydn Washington, co-author of Climate Change Denial
Bravo Haydn, well said. The push for nuclear is both cynical and frightening. The problem, as I wrote about 2 years ago on ABC Unleashed (to a massive response, people are really concerned about this) http://www.abc.net.au/unleashed/30624.html,is that no matter what improvements in technology occur, the chance of human error is always there, and the consequences, as seen in Japan most recently, are extreme and widespread.

Bern at 11:28 AM on 8 May 2011

Lindzen Illusion #5: Internal Variability
KR - I think that was dorlomin's point. Policy (i.e. a lack of action on global warming) is being made on the basis of idiosyncratic minority views (i.e. Lindzen, Christy, Plimer, and their friends, a number of whom have no specific expertise in this area), while dismissing or ignoring the views of the 99% of climate scientists who think we have a serious problem on our hands.

Tom Curtis at 11:19 AM on 8 May 2011

Frauenfeld, Knappenberger, and Michaels 2011: Obsolescence by Design?
Below is FK&M 2011's key figure modified to include a 2010 value and to change the 10 year trailing mean to a straight 10 year mean. The 2010 value is calculated from Tedesco's figure as detailed @183. The image was made purely by manipulating images.

What difference does it make? 1) The 2010 value falls within the 95% confidence limits of eight, or possibly nine of reconstructed pre 1979 values, compared to twenty for 2007. 2) The 10 year mean ends with a value of 0.9 compared to 0.7 for 2009. For comparison, the peak of the 10 year mean in 1 in 1924. 3) A minor graphical point, the 10 year mean ends with an uptick instead of levelling of as it does without 2010 included. These may look like minor features, but viewed at normal viewing scale, they do stand out and give a distinctly different impression. In particular, when coupled with the trailing mean, ending at 2009 gives the visual impression that the most recent melt values may have reached a peak at a decadal mean distinctly lower than the peak in 1924. Including 2010 and using a standard 10 year running mean, in contrast, gives the visual impression of a still rising value which is already at the same levels of the 1924 peak. I think this difference is important for spin, but not in science. Contrary to some commentators I do not think the use of a trailing mean is 'unscientific'. It is certainly not best practise, and can mislead the unwary, but it will not mislead anyone who actually reads the captions (unless they want to be). On the other hand, I do think the difference between 0.7 and 0.9 on the 10 year mean, and between the peak recent value lying within the confidence interval of just eight rather than 20 reconstructed values is scientifically relevant. That difference approximately doubles our confidence that the most recent peak value is in fact the actual peak value over the entire period, at least using Lucia's simplistic interpretation of confidence intervals. The difference in ten year means also significantly increases our confidence that current melts have at least matched and will probably soon exceed those of the 1920s. It also gives us reasonable confidence that they already exceed those of any other decade. That last point probably deserves some attention. It is a clear emphasis of FK&M 2011 that "We find that the recent period of high‐melt extent is similar in magnitude but, thus far, shorter in duration, than a period of high melt lasting from the early 1920s through the early 1960s." (My emphasis) However, the recent period including 2010 exceeds in magnitude all but one decade of of that forty year period. Given that 2010 also appears to be confirming Box's very plausible prediction, it would be a foolhardy person to argue from FK&M that ice melts in Greenland will soon, if they do not already, cause far more rapid rises in sea level than at any time in the twentieth century.

haydnwashington at 10:47 AM on 8 May 2011

Q and A with Dr Haydn Washington, co-author of Climate Change Denial
I guess two points: 1) Re probability and certainty, Cloa seeks to argue that 'true science' comes with 'proof' while climate science is rubbery. This is a common denial argument which paints mainstream climate science as 'junk science'. The reality is that the coherence of evidence in regard to human-caused climate change is overwhelming. It comes from many sources and almost all show that warming is worse than it was orignally projected to be. In regard to the statement about scientific method in general, this is just mistaken, as any book on the history and philosophy of science will explain to you. 2)Barry Brooks seeks to make an ad hominem attack that since I doubt the usefulness of nuclear power I am either ironic, insulting or misinformed. Well sorry Barry I am not being ironic, nuclear is too little too late, too expensive and too dangerous. You dont solve one major problem with another. You might consider it if it was the only alternative - but it isnt. As was shown in your debate with Dr Mark Diesendorf at UNSW, renewable energy is a far better alternative to put our development money into than nuclear. Issues such as baseload power are now solved. Spain is spending $20 billion on installing Concentrated Solar Thermal. It is time for Australia to make use of our fantastic renewable resources, not follow some Cornucopian nuclear fantasy. Renewable are both feasible and sustainable. Its time to accept reality and move rapidly to a renewables future. Both Mark Diesendorf and Barry Pittock in their books (plus Beyond Zero Emissions in their Stationary Energy Study)show this can be done.

Daniel Bailey at 09:26 AM on 8 May 2011

Frauenfeld, Knappenberger, and Michaels 2011: Obsolescence by Design?
As a furtherance to Albatross' comment at 161 above, there is a new release from Snow, Water, Ice, Permafrost in the Arctic (SWIPA) 2011 entitled: Executive Summary and Key Messages English translation here (WARNING: Big File [31 Mb]; fast connections only!) For those without high-speed access: Key finding 1 The past six years (2005–2010) have been the warmest period ever recorded in the Arctic. Higher surface air temperatures are driving changes in the cryosphere. Key finding 2 There is evidence that two components of the Arctic cryosphere – snow and sea ice - are interacting with the climate system to accelerate warming. Key finding 3 The extent and duration of snow cover and sea ice have decreased across the Arctic. Temperatures in the permafrost have risen by up to 2 °C. The southern limit of permafrost has moved northward in Russia and Canada. Key finding 4 The largest and most permanent bodies of ice in the Arctic – multiyear sea ice, mountain glaciers, ice caps and the Greenland Ice Sheet – have all been declining faster since 2000 than they did in the previous decade. Key finding 5 Model projections reported by the Intergovernmental Panel on Climate Change (IPCC) in 2007 underestimated the rates of change now observed in sea ice. Key finding 6 Maximum snow depth is expected to increase over many areas by 2050, with greatest increases over Siberia. Despite this, average snow cover duration is projected to decline by up to 20% by 2050. Key finding 7 The Arctic Ocean is projected to become nearly ice-free in summer within this century, likely within the next thirty to forty years. Key finding 8 Changes in the cryosphere cause fundamental changes to the characteristics of Arctic ecosystems and in some cases loss of entire habitats. This has consequences for people who receive benefits from Arctic ecosystems. Key finding 9 The observed and expected future changes to the Arctic cryosphere impact Arctic society on many levels. There are challenges, particularly for local communities and traditional ways of life. There are also new opportunities. Key finding 10 Transport options and access to resources are radically changed by differences in the distribution and seasonal occurrence of snow, water, ice and permafrost in the Arctic. This affects both daily living and commercial activities. Key finding 11 Arctic infrastructure faces increased risks of damage due to changes in the cryosphere, particularly the loss of permafrost and land-fast sea ice. Key finding 12 Loss of ice and snow in the Arctic enhances climate warming by increasing absorption of the sun’s energy at the surface of the planet. It could also dramatically increase emissions of carbon dioxide and methane and change large-scale ocean currents. The combined outcome of these effects is not yet known. Key finding 13 Arctic glaciers, ice caps and the Greenland Ice Sheet contributed over 40% of the global sea level rise of around 3 mm per year observed between 2003 and 2008. In the future, global sea level is projected to rise by 0.9–1.6 m by 2100 and Arctic ice loss will make a substantial contribution to this. Key finding 14 Everyone who lives, works or does business in the Arctic will need to adapt to changes in the cryosphere. Adaptation also requires leadership from governments and international bodies, and increased investment in infrastructure. Key finding 15 There remains a great deal of uncertainty about how fast the Arctic cryosphere will change in the future and what the ultimate impacts of the changes will be. Interactions (‘feedbacks’) between elements of the cryosphere and climate system are particularly uncertain. Concerted monitoring and research is needed to reduce this uncertainty. The biggest unanswered questions identified by this report are: • What will happen to the Arctic Ocean and its ecosystems as freshwater is added by melting ice and increased river flow? • How quickly could the Greenland Ice Sheet melt? • How will changes in the Arctic cryosphere affect the global climate? • How will the changes affect Arctic societies and economies?

KR at 09:17 AM on 8 May 2011

Lindzen Illusion #5: Internal Variability
dorlomin - I'm afraid the idiosyncratic minority view is Lindzens, not the consensus. I cannot speak to policy, as the US really doesn't have one at the moment. Lindzens climate sensitivity numbers are way out on the fringe, his science and claims are poorly (if at all) supported, his views have been debunked. Sorry... I'll respect the time he's put in - but his views are nonsense when compared to the evidence.

dorlomin at 09:04 AM on 8 May 2011

Lindzen Illusion #5: Internal Variability
@David Horton post 5. Lindzen is a genuinely great atmospheric physicist. He has a view that dissents from the mainstream. But there is nothing unusual in that, many scientists who produce great work in a field have odd views on other areas of that field. Often scientists looking at the same evidence come to differing conclusions. Look at Out Of Africa vs Multiregional in terms of human evolution, the same bones were used by both sides to make their cases. Lindzen holds his view honestly and is entitled to it. The problem comes that policy is being based on ideosyncratic minority views rather than the bulk of the scientists.

funglestrumpet at 08:45 AM on 8 May 2011

Lindzen Illusion #5: Internal Variability
David Horton - You may be right. However, there is something wrong if they can be allowed to get away with such behaviour. In any event, there must be something that can be done to expose the weakness of the support they get from their peers. In the eyes of the public, the case you advance comes down to two arguments, both difficult to grasp. The concept of the relative support from their peers is not part of the equation. Something I hoped to promote. There is surely a need for action when debunked material can be presented for "two decades" with no shame on the part of those concerned. What I suggest would give those who wish to 'trot' out such individuals an accessible resource to get a feel for the quality of their proposed guests. Most importantly, they would not need to know the science, the language on its own would speak volumes. It could even be seen as a resource that could be pointed to in any letters of complaint to the heads of organisations when some Presentations Director has booked the likes of Lindzen and suchlike.

Steve Bloom at 08:18 AM on 8 May 2011

Frauenfeld, Knappenberger, and Michaels 2011: Obsolescence by Design?
Any chance of getting error bars added to the graph, Chris? Re that '20s/'30s bump, someone said earlier that it was down to solar influences. IIRC that's not right, although perhaps it's a small factor, and the big one (scraping my memory here) was likely black carbon from industrial emissions.

chris at 07:48 AM on 8 May 2011

Frauenfeld, Knappenberger, and Michaels 2011: Obsolescence by Design?
Below are a couple more graphs; I’ve aligned them together so that they are easier to compare, with a description above all the graphs. See additional comments here for info on where the data comes from. A. as presented by FKM2011 with a 10 year trailing running average. B. as a 10 year running average should be presented (i.e. without a lag) – This shows the data up to the year up to which the running average can be calculated. Obviously the more years in the running average, the more years at the front and back of the series are left uncalculated. There isn't any justification I can think of for shifting the running average as if to pretend that the average has been calculated for each year to the end of the series; it hasn’t. Another way of saying this is that the averaged melt index value of around 0.5 was reached already by 2004. It didn't take until 2009 as FKM's analysis pretends. What it does next depends... C. as a 5 year running average, and incorporating the 2010 melt data, which differs a little from my previous post to accommodate the evidence that the 2010 melt was a little larger than 2007. I found I couldn’t reliably do this exactly as Tom suggested in @183, since the FKM data and Tedesco data aren’t related by a single specific scaling factor. So I’ve somewhat arbitrarily given 2010 a melt index of 2.2. It doesn’t make much of a difference if it is 2.0 (same as 2007), 2.1 or 2.2. The melt index value at the end of the record (2008) has a value very near 1.0. Make of it what you will. FKM's smoothing is somewhat illiterate scientifically-speaking, but they are trying to sell a particular message and the reviewers gave them a pass on this. On the other hand the real impact of the high 2010 melt year will only be apparent if subsequent years are also high or higher. If that happens to be the case as physics might predict, then a robust 10 year smoothing of the data should help to suppress the rise for a little longer! A.

David Horton at 07:45 AM on 8 May 2011

Lindzen Illusion #5: Internal Variability
Fungelstrumpet - Lindzen serves (as does Plimer) as the kind of token "respectable" scientist who "doesn't believe" in global warming who can be trotted out, again and again to show that "the science isn't settled" (otherwise respectable scientists wouldn't dispute it) and the consensus is not 100% (only 99% therefore there is room for doubt). Lindzen seems absolutely content with this role. Not much need to scientifically dispute him in the ordinary sense (yes there is "natural variability" but every graph shows it is occurring around a rising mean; what are the odds of "natural variability" not only coinciding with low sun input but sharply rising CO2 in the past 30 odd years?). As with Monckton however, his importance is not in the rubbish science but simply that he exists and is vocal and highly visible.

~Qt~ at 05:25 AM on 8 May 2011

Lindzen Illusion #5: Internal Variability
Didn't Hansen et al. (2011) actually conclude that the Earth's energy imbalance had decreased? "In this section we examine why the calculated energy imbalance declined during the past decade. In section 13 we discuss factors that may account for the difference between expectations in Fig. 19A and the observed planetary energy imbalance." (pg. 36)

funglestrumpet at 05:08 AM on 8 May 2011

Lindzen Illusion #5: Internal Variability
dana1981 – doesn’t seem to be working, does it? At the moment it is all via proxies. I believe we should take the fight to them, heaven knows, the science sits fair and square on this side of the fence. As it is, anyone that has little or no science is just going to see one side saying one thing and the other side saying the opposite, both statements being impenetrable. What I am suggesting provides a mechanism that raises awareness. One does not have to understand the science to recognise waffle when one sees it. I really don’t think that business as usual is a luxury that we can afford for too much longer.

Albatross at 04:59 AM on 8 May 2011

Frauenfeld, Knappenberger, and Michaels 2011: Obsolescence by Design?
Logicman @168, Good sleuthing. The mind boggles. Regarding the JGR-A numbers, I could be wrong, but I'm pretty sure that those numbers represent the number of downloads. If so, right now, the paper in question is in third place. For what it is worth, the paper doesn't feature under "editors" highlights"-- no surprise there, they are probably embarrassed about it. That all aside, I find it odd that the "skeptics" denounce popularity contests or polls, yet as soon as a 'skeptic' paper gets quite a few downloads they get all excited. A good number of those downloads are probably by glaciologists thinking "WTF?!".....I'm sure Lindzen and Choi also ranked high shortly after it was published ;) Chris @179, nice work! Looking forward to seeing the your updates should you decide to pursue this further.

dana1981 at 04:37 AM on 8 May 2011

Lindzen Illusion #5: Internal Variability
funglestrumpet - Lindzen's arguments don't have any impact in and of themselves. Where they have an impact is when somebody references them to propagate and defend a climate myth. Here we are providing a counter-reference to deflate the value and effectiveness of Lindzen's arguments. If people make use of this resource, then others will notice.

logicman at 04:29 AM on 8 May 2011

Frauenfeld, Knappenberger, and Michaels 2011: Obsolescence by Design?
#170 - Albatross Here's a similar quote from Michaels posted on Forbes. "In an unbiased world there should be an equal chance of either underestimating or overestimating the climate change and its effects, which allows us to test whether this string of errors is simply scientists behaving normally or being naughty. What’s the chance of throwing a coin six times and getting all heads (or tails)? It’s .015. Most scientists consider the .050 level sufficient to warrant retention of a hypothesis, which in this case, is that the UN’s climate science is biased." Forbes.com The worst counterfactual statement there by Michaels is: "Scientists, as humans, make judgemental errors. But what is odd about the UN is that its gaffes are all in one direction. All are exaggeration of the effects of climate change." Elsewhere, the new maths: 54 = 1 Last week, the most popular article from among those recently published in the American Geophysical Union’s (AGU) Journal of Geophysical Research-Atmospheres was one which presents a 225-yr reconstruction of the extent of ice melt across Greenland. my emphasis. The image posted shows the paper as 54th most popular download. http://www.worldclimatereport.com/...

Ian Forrester at 03:59 AM on 8 May 2011

Q and A with Dr Haydn Washington, co-author of Climate Change Denial
Barry Brook said:

are you trying to be ironic, or insulting, or are you simply misinformed?

He is being honest, think about it for a few minutes.

funglestrumpet at 03:51 AM on 8 May 2011

Lindzen Illusion #5: Internal Variability
Just how many times must we simply sit back and allow Lindzen to give us his illusions, Monckton with myths and Christy his crocks? Isn’t it about time this community took the initiative? How about asking Lindzen and his compatriots for their response to these debunking posts and tell them you are going to make public the challenge and also the ensuing correspondence to a conclusion? If a point is reached where a stalemate is reached, the opportunity to join in is offered to those most competent to contribute. This site has enough kudos to be able to contact anyone these ‘sceptics’ happen to use to publish their disinformation and show them how much they have been deceived. It is fun to see their arguments being demolished, but like the warm feeling one gets from peeing ones pants while wearing a dark suit, who notices?

Bob Lacatena at 03:38 AM on 8 May 2011

Why 450 ppm is not a safe target
44, Jesús,

I think Hansen tries to add something to the literature, and I think it's the suggestion that all current projections may be too low.

Yes, absolutely, and I get the impression that the 2011 paper is intended to provide further weight to this argument, through paleoclimate evidence (i.e. comparison to Eemian temperatures and sea levels, without reference to time frame). I think I separate from you in that I think that Hansen, and RC's interpretation of Hansen, is that he never actually made any specific projections, and certainly not within any particular time frame. He is pushing the idea that sea level rise will be non-linear, and in the simplest model for that (ice loss doubling every 10 years) this would project to a 5m increase by 2095... but he's not putting that out there as a serious prediction, only as a stark example of the potential difference between linear and non-linear. I think that since then he has gone out of his way to avoid being specific. He is pushing the idea of a non-linear sea level rise without making any specific predictions relative to time-frame. I think RC understands this thoroughly, which is why they appear to be silent. They don't refute 5m because they don't feel any such prediction was ever made. They don't refute "meters" because it is an unbounded, non-specific warning.

I don't think 1.5 m is "multi-meter"

I don't either. Without coming out and saying it, I think Hansen is implying 2m-5m, with the idea that 2m is at the low end, and anyone projecting below that is in for a surprise... but he's never come out and said that... this is my interpretation.

I think that's what most readers are interpreting...

No, I think they're taking away 5m because that's what the post above says, and it should be rectified ASAP, because it's going to confuse people.

what is important, in my view, is that, when talking about Hansen & Sato SLR numbers, we stress that the most widely accepted projections for 20th century SLR cluster around 1 m.

Agreed (except I know you meant 21^st, not 20^th, century), as long as people understand that those numbers presume a linear increase, and there are reasonably strong arguments to at least consider that that may not be the case, and we may be underestimating the problem (for the second time). I think the last bit from Hansen and Sato 2011 worth pointing out is this:

We conclude that available data for the ice sheet mass change are consistent with our expectation of a non-linear response, but the data record is too short and uncertain to allow quantitative assessment. The opportunity for assessment will rapidly improve in coming years if high-precision gravity measurements are continued. Finally, we note the existence of a strong negative feedback described by Hansen (2009) that comes into play when the rate of sea level rise approaches the order of a meter per decade. Such an iceberg discharge rate temporarily overwhelms greenhouse warming, cooling high latitude atmosphere and ocean mixed layer below current levels. Ice sheet mass loss may slow in response to this cooling...

That last bit, if it ever comes to past (certainly not in our lifetimes, I'm sure) is a downright scary image.

chris at 03:25 AM on 8 May 2011

Frauenfeld, Knappenberger, and Michaels 2011: Obsolescence by Design?
A general point/opinion about this story of which I think there are 3 elements (I hope the moderators consider my comments appropriate since this thread clearly isn’t just about the science; it’s also about science misrepresentation, Greenland melt and the scientific review process): 1. Misrepresentation of science. It’s very sad that enormous sums are invested in institutions whose purpose is to cheat Joe Public out of one of the essential requirements of a democracy (the information required to make informed decisions). The posts by Albatross from #161 onwards, are probably the most relevant on this thread, since they address a particularly ugly problem. 2. Greenland ice melt. It’s a simple fact that when viewed in terms of raw numbers without consideration in the context of independent knowledge, Greenland ice melt doesn’t seem to be so very much different now that during the early-mid 20th century......yet. This can easily be misrepresented. 3. Scientific review. However the data was presented in FKM2011, they would have been used to support dismal rhetoric of the sort that Albatross has highlighted. However, IMHO some of the problems could have been addressed if at least one reviewer had chosen to review the paper properly. I detect an undercurrent of potential unhappiness about the editorial decisions on this paper, but in the absence of inside knowledge (which I have little interest in - although if it does appear it's bound to be gossipworthy!) I am going to support the editor here. He gave the manuscript to an expert reviewer, and the latter decided not to bother reviewing the paper properly. We know this since the reviewer has dumped his review on the blogosphere. There are some absolutely first class institutions in the US (the National Park Service, The National Institutes of Health and the system of public and private universities are some of my favourites). The value of the latter two in terms of advancing scientific knowledge is partly due to the peer review system in all its forms. I think we should be careful to nurture these since they can be powerful weapons in the face of efforts at self-interested misrepresentation.

chris at 03:18 AM on 8 May 2011

Frauenfeld, Knappenberger, and Michaels 2011: Obsolescence by Design?
Thanks Marco; I haven't ever bothered to look at these things since normally you can get the data by other means. I'll be very interested to know how well these actually work... O.K. Tom. However the added benefit of including the 2010 data (melt index 2.0 in my analysis) and dropping 2000 is already made in my re-analysis (second of my reconstructions in my post above). So increasing the 2010 melt index a tad more won't have much of an additional effect. I'll do it anyway...

Bob Lacatena at 03:16 AM on 8 May 2011

Lindzen Illusion #2: Lindzen vs. Hansen - the Sleek Veneer of the 1980s
I would point out that since angusmac has argued that Scenario C most closely matches observed temperatures, and therefore by his logic is the correct one to consider... ...he has in turn proven that actual CO₂ emissions since 1998 have represented a rapid curtailment of trace gas emissions (Hansen's 1998 words). angusmac has successfully proven that we've already abandoned fossil fuels, and so there is no longer any danger of climate change. Let me be the first to congratulate everyone on a job well done. Humanity, and civilization, are saved by a simple and convenient re-interpretation of history. I wish I'd thought of that.

Bob Lacatena at 03:12 AM on 8 May 2011

Lindzen Illusion #2: Lindzen vs. Hansen - the Sleek Veneer of the 1980s
angusmac seems to be woefully lost in the difference between a scenario -- a set of preconditions on which to base a projection -- and the projection resulting from that scenario. He wants to argue that Scenario X is the right one because the end result matches observations, without regard to the fact that the conditions underlying Scenario X never came to pass. He then further obfuscates things by using the 10-year-old description of a scenario (such as "business as usual" for Scenario A) as an argument that it should apply today (because we currently describe what we've done since 1998 as "business as usual"). It's all really a very clever misunderstanding. angusmac, here are some basic facts that point out the major fallacies in your comments to date: 1) Scenarios A, B, and C represent emissions growth patterns, not temperature predictions. 2) Hansen's own description of those scenarios at the time was this:

Scenario A assumes continued exponential trace gas growth, scenario B assumes a reduced linear linear growth of trace gases, and scenario C assumes a rapid curtailment of trace gas emissions...

Note the use of the word "continued," which is sort of like "business as usual," but I hope that you can appreciation the difference. 3) Actual emissions growth since 1998 has been linear (i.e. scenario B) even though at that time the pattern had been exponential, and would have matched scenario A. This makes scenario B the best match to actual events for the emissions on which each projection is based 4) So whatever projection went with scenario B (which more closely matches actual emissions) is the one we should consider. 5) Since that projection accompanied a pattern of emissions which never came to pass (i.e. scenario B is closest to, but not equal to, actual emissions since 1998) it is fair to adjust the projection in a minor fashion to more closely match what it might have said, had scenario B matched actual emissions. Which of these rather simple points still eludes you?

Jesús Rosino at 02:50 AM on 8 May 2011

Why 450 ppm is not a safe target
Sphaerica #39, Sorry for repeating, but I want to make it clear that I didn't mean to criticise RC for being silent, I was rather interested in RC's opinion and I thought their silence was also telling. That's because I think the possibility of 2-5 m. SLR in this century suggested by Hansen & Sato is important enough as to devote an entire post to it, especially when they've been posting regularly on the subject. However, in the absence of a specific RC blog post, you've digged deeper than I to give some insight into RC's opinion. Firstly, they seem to place Hansen's numbers within the bounds of Pfeffer et al. I do not go along with that. Pfeffer et al says 2 m. is their highest conceivable bound, but they find it highly unlikely and they add that "more plausible but still accelerated conditions could lead to sea level rise of 80 cm by 2100" (my bold). Hansen and Sato says that under BAU scenarios, multi-meter SLR "are not only possible, but almost dead certain" and that 5 m is possible [citations at the end of comment #38] I don't think 1.5 m is "multi-meter". I think that's downgrading the meaning of "multi". I think multi-meter means at lest 2 (and I think that's what most readers are interpreting, especially that was the reading of the comment I meant to reply to). I think Hansen tries to add something to the literature, and I think it's the suggestion that all current projections may be too low. So not only I don't think Pfeffer and Hansen are in the same bounds, but I think they're just opposite. Then we move on to RC's relevant statement:

"We stress that no-one (and we mean no-one) has published an informed estimate of more than 2 meters of sea level rise by 2100."

Agreed. That's why I think RC is de facto rejecting Hansen & Sato's suggestion. In any case, it doesn't matter, what is important, in my view, is that, when talking about Hansen & Sato SLR numbers, we stress that the most widely accepted projections for 20th century SLR cluster around 1 m.

Tom Curtis at 02:50 AM on 8 May 2011

Frauenfeld, Knappenberger, and Michaels 2011: Obsolescence by Design?
chris @181, I'm sorry if I was not clear enough. I just compared three data points on the Tedesco chart, 2005, 2007, and 2010. Setting the difference between 2005 and 2007 as 1, then the difference between 2005 and 2010 is 1.2. The value for 2010 = (v_2007 - v_2005) * 1.2 + v_2005, where v_x stands for the value for the year x. This assumes that FKM and Tedesco's Ice Melt Indices retain proportionality, which is probably not true, but close enough. The addition of the 2010 value does make a significant difference to the 10 year lagged mean in part because 2000 has a very low (in fact negative) ice melt index. Carrying the mean forward to 2010 not only adds 2010 to the ten year lagged mean, but drops 2000 from it, hence the relatively large effect. I would certainly like to see the author's publish a chart including 2010, or better yet, publish the annual values from the current chart so that we can remove the guess work.

Marco at 02:33 AM on 8 May 2011

Frauenfeld, Knappenberger, and Michaels 2011: Obsolescence by Design?
Chris, just a suggestion if you want to make any future analysis: there are several programmes that can extract data from graphs. Wikipedia even has a webpage about it: http://en.wikipedia.org/wiki/Converting_scanned_graphs_to_data with links to several programmes.

chris at 02:30 AM on 8 May 2011

Frauenfeld, Knappenberger, and Michaels 2011: Obsolescence by Design?
O.K. Tom; I'll do that later. However it's not obvious to me what your value should be. If you can suggest a value for the 2010 melt index based on the Tedesco data and compatible with the FKM reproductions in my post (2.2 ??), I'll use it. It will make very little difference to the 10 year lagged running average. Having plotted the data it's clear that's a half-assed means of smoothing time series data anyway (reviewer went AWOL) - It'll make a little more difference to the unlagged 5 year running average. I'll also plot the 10 year unlagged smooth which I think will illustrate how misleading a lagged 10-year smooth is, especially for data that is seemingly rising quite quickly at the contemporary end point. (Any other ideas, I'll plot them!) P.S. Note that when I say "fit" in my post with plots, I don't mean "fit" at all. I mean "running average" or "smoothing"... also it's conceivable that I didn't reproduce the data points exactly correctly, although I made sure that there were 10 data points for each decade of data. If someone thinks I've made any tiny errors, I can easily correct these. If anyone wants my list of melt index vs year, I can post those too.... Of course the authors could post theirs and that would be even better....

Marcus at 02:27 AM on 8 May 2011

Lindzen Illusion #3 and Christy Crock #5: Opposing Climate Solutions
"Whereever you are Marcus - tell us what the life cycle costs of coal fired generation are compared with PV Solar." Its right there in the text you quote. Official industry figures put *generation* cost of coal at $0.06c/kw-h for coal (which I assume is based on all of the factors you mention), & $0.33c per kw-h for PV solar. Of course, the distribution costs for coal-fired electricity are considerably higher, which is why the *retail* cost of coal is closer to $0.30c per kw-h. Of course, I'm curious why you have this constant obsession with PV solar? I mean, you are aware that there are many other sorts of renewable energy technologies out there-most of them cheaper than PV's (though the cost of PV electricity is falling all the time). Solar thermal has a life-cycle cost of $0.10c/kw-h to $0.12c/kw-h (without storage). Wind is around $0.08c/kw-h (without storage). I can't recall what tidal or geothermal power cost, but do recall that they're around the same range as Wind or Solar Thermal. Hydro power is around $0.03c/kw-h to $0.05c/kw-h. So yes, PV's still have a way to go before their generation costs are competitive with those of coal but, for local energy supply (say, within around 5km-10km of the generation site) the total costs for PV solar even out quite nicely. "That includes the capital cost of the plant, fuel costs, maintenance and running costs divided by the total energy generated over the plant life." You are aware that there's more to calculating life-cycle costs than that. There is the so-called "Discount Rate", which factors in things like depreciation & expected return-on-investment times. Of course, there is a long history of economists applying higher discount rates to coal & nuclear than to renewable energy projects, thus causing the latter to appear even *more* expensive than they really are-or need to be. Also, how can you properly factor something like fuel costs, over a 30-50 year lifespan, when you have absolutely *no clue* how expensive the fuel is going to be in 20 years time or, even more importantly, how expensive the fuel needed to extract the coal is going to be.

Marcus at 02:15 AM on 8 May 2011

Lindzen Illusion #3 and Christy Crock #5: Opposing Climate Solutions
"Apart from the personal derogation" Hilarious, you're the one who accused me of being ignorant-I was merely responding in kind. I think someone is being just a little bit too precious for words-maybe because their arguments are being made mincemeat of, right Ken? "I am happy to engage you on the numbers Marcus, not florid claims about 'subsidies' by governments who seem to be hell bent on helping out vested interests in the 'fossil fuel' industries rather than serving the people." Are you really Ken? Well I've given some very clear numbers above (#97 & #98)-from no lesser an authority than the EIA. You care to dispute these figures, or try to justify such large subsidies for such a mature & profitable industry as the coal & oil industries clearly are? Also, I never made accusations of conspiracies. A large number of the subsidies date back to when the technology was still relatively new, & no-one has been bothered to remove them-a decision that certainly isn't helped by a very powerful fossil fuel lobby. Also, if you think politicians put the interests of the electorate ahead of powerful lobbies, then you really *do* live in a parallel universe. That's not conspiracy theory, that's a simple "whoever pays the piper, calls the tune". I really don't understand how you continue to be incapable of accepting these basic facts.

dana1981 at 01:44 AM on 8 May 2011

Lindzen Illusion #2: Lindzen vs. Hansen - the Sleek Veneer of the 1980s
Albatross - I kind of tried to make that point, that with this data, the most likely sensitivity is actually closer to 3.4°C.

dana1981 at 01:43 AM on 8 May 2011

Lindzen Illusion #2: Lindzen vs. Hansen - the Sleek Veneer of the 1980s
angusmac - as I've said, climate scientists aren't in the business of predicting how emissions will change. That depends on policymakers, not physics. Perhaps if emissions had continued to accelerate at the rate they were in 1988, Scenario A would have become reality. Regardless, nothing was "amended downward". A different scenario became reality. Yes, coincidentally when adjusting Scenario B to reflect 3°C sensitivity, current temp projections come close to Scenario C with 4.2°C sensitivity. I think it's kind of silly to obsess over coincidences though.

Tom Curtis at 01:43 AM on 8 May 2011

Frauenfeld, Knappenberger, and Michaels 2011: Obsolescence by Design?
Chris @179, by close comparison of Tedesco's figure reproduced by Lucia @140, it shows the 2010 melt to be 120% of the difference between 2005 and 2007 higher than 2005. On your chart that would certainly make a visually discernible difference both to the location of the 2010 value, and to the end point of the running mean (five year or ten year). This is slightly more than the 116.7% of the 2005/2007 separation I reported earlier based on figure 2 of the main article. If you where to rework your graphs based on this value, it would save me my laborious attempt to do something similar to what you have done.

Albatross at 01:32 AM on 8 May 2011

Lindzen Illusion #2: Lindzen vs. Hansen - the Sleek Veneer of the 1980s
Dana, Believe it or not, the above obfuscation has given me an idea. I'll try and post about it this weekend. Basically what it boils down to is that these data suggest that a sensitivity of +3 K may be somewhat too low.

bibasir at 01:22 AM on 8 May 2011

Q and A with Dr Haydn Washington, co-author of Climate Change Denial
There are some great quotable lines. Skepticism is about looking for the truth, denial is about hiding from it. ‘global warming happened in the past’. Yes it did, but bushfires happened in the past, yet we know arson is not a good idea

Bob Lacatena at 01:15 AM on 8 May 2011

Why 450 ppm is not a safe target
Martin, concerning ocean cores... I've certainly never seen the statement that ocean cores are a "much better guide to global mean temperatures than ice cores" anywhere. It's not in Hansen and Sato 2011. I'm not sure it's a question that scientists debate. They are different tools, with different qualities, and they are used as such and interpreted as needed. From Hansen and Sato 2011:

Ice cores and ocean cores are complementary tools for understanding, together providing a more quantitative assessment of the dangerous level of human interference with the atmosphere and climate.

and later

Ice core and ocean core records each have limitations as a measure of global temperature. Here we point out constraints on both records and hypothesize a reason why these two records seem to differ during recent interglacial periods.

This is followed by a detailed discussion of the advantages and disadvantages of each. And, concerning their impact on estimates of temperatures in the Eemian:

Ice cores and ocean cores are valuable complementary sources of climate information. Fig. 4 shows that they provide similar pictures of Milankovic glacial cycles, with one exception. Ice cores suggest that the Eemian and Holsteinian interglacials were warmer than the Holocene by 2°C or more. In contrast, ocean cores suggest that these earlier interglacials were warmer than the Holocene by at most one degree, perhaps by only tenths of a degree Celsius.

Of course, this is just from Hansen and Sato 2011. Your question is about the "climate science mainstream"... which I'm not sure is something that exists.

Bob Lacatena at 01:01 AM on 8 May 2011

Why 450 ppm is not a safe target
Martin, I'd point out that Hansen suggests that in a simple model sea level rise would be geometric, not exponential (although I made the same mistake in an earlier comment, saying "exponential" when I'd meant "geometric"). That is, he argues that if rate of ice mass loss is doubling every ten years, then sea level rise could double every ten years. More importantly, however, we are at the very start of any ice melting, so there would as yet be no measurable geometric increase in sea level rise. Given this, your statement #2 above would not be close to the climate science mainstream... but that's not relevant, and that's some of Hansen's point. The question isn't what's happened until now, the question is what will happen. His main point is that if melt rates are not linear, then sea level rise will not be linear, even if sea level increases seen to date are linear. Your statement #3 is also invalid as stated. It is true that the rate of loss of ice in Greenland appears to have doubled in the past ten years. It is not valid to instantly extend this to say that this trend will continue without variation. In addition, some have questioned the proper interpretation of the GRACE satellite data (specifically, the impact of isostatic rebound on those measurements), so even the exact measure of loss is not yet certain. I think the rate of ice mass change in Greenland and the Antarctic is still in an early "wait and see" mode.

KR at 00:50 AM on 8 May 2011

Climate is chaotic and cannot be predicted
neil - Gah; all that typing and I forgot to include the main point. Given a system with multiple equilibria, a wide variety of initialization points will almost certainly provide a sampling of the equilibria, with various initializations stabilizing to local minima in the state space. That doesn't mean it's easy to move from one equilibrium to another, just that they exist. That said, we look to be heading to an ice-free Arctic, and if we maintain high temperatures for a few millennia we may see significant loss of the Antarctic as well. Florida (and Bangladesh) are not great long term real-estate investments.

KR at 00:42 AM on 8 May 2011

Q and A with Dr Haydn Washington, co-author of Climate Change Denial
michael sweet - Here in my area we have a large group of people (complete with decorated RV's) touring the capital, handing out pamphlets, claiming that the end of the world will be at 6PM, May 21st (local time, rolling apocalypse). To balance that, there's a group of atheists (blasphemy required as a hiring condition) spread across the USA, that for a fee and continuing subscription - promise to come by, collect your pets, and take care of them if you are swept up in the Rapture. It takes all kinds...

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