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Phila at 02:06 AM on 5 May 2011CO2 is plant food? If only it were so simple
HR: I'm not here to paint utopian visions just to counter unnecessary pessimism. Acknowledging the full seriousness of AGW, and believing that we can take intelligent steps to address it, is optimism. Denying that AGW exists is wishful thinking, at best. Believing that the people who are best equipped to understand AGW are liars, incompetents or dupes is pessimism. Your stance seems to me to be a combination of wishful thinking and pessimism. Human ingenuity is incredibly powerful, but it works best when people pull their heads out of the sand and face facts. -
KR at 02:02 AM on 5 May 2011Frauenfeld, Knappenberger, and Michaels 2011: Obsolescence by Design?
Chip - Thank you again for the interesting discussion. I am of the opinion that surface melt is only one factor in mass loss, and that hence this single study is insufficient to judge or predict (or for that matter to make statements about) such mass loss. The GRACE satellites, altimetry, and ice speed measurements provide a more complete picture of ice loss, and hence sea level contributions. While I feel it unfortunate that you did not include the 2010 data which should at the least have modified your summary and conclusion sections, the surface melt data and methodology should be useful going forward. -
dana1981 at 01:56 AM on 5 May 2011Lindzen Illusion #4: Climate Sensitivity
Thanks KR. Indeed the revision was submitted over a year ago and was never published, likely for the reasons you describe. -
KR at 01:53 AM on 5 May 2011Lindzen Illusion #4: Climate Sensitivity
Lindzen and Choi's 2010 paper, or at least an initial version of it (Feb. 2010), is available via this link. Upon reading it, they are still calculating strictly upon tropical data, using a simple geometric extension of tropical insolation to the rest of the globe, and still do not address heat transfer in/out of the tropics, which is considerably larger in magnitude than their feedbacks (one of the Trenberth criticisms). For example, "We argue that feedbacks are largely concentrated in the tropics and extend the effect of these feedbacks to the global climate." It appears to be a rehash of their 2009 paper, without any significant extensions, or for that matter, significant replies to the many criticisms. I can see why it hasn't been published yet. -
Chip Knappenberger at 01:49 AM on 5 May 2011Frauenfeld, Knappenberger, and Michaels 2011: Obsolescence by Design?
Whew, lots of questions this morning (my time)! First of all, thanks for all the interest in our paper. I think that I’ve already pretty much explained my side of things (most of the technical questions that are being raised are covered in the paper, so I would encourage folks to read it if they want specific answers to questions about the methodology). I think as we all can see, my answers/responses do not really satisfy anyone. So I think our useful time together is fast approaching an end. Instead on going through the questions one by one and rehashing everything that we’ve hashed through already, I’ll try this…. Our paper was designed to produce a longer temporal framework of the ups and downs of the extent of surface ice melt across Greenland. It was inspired by work published by Dr. Tom Mote in GRL back in 2007 in which Dr. Mote demonstrated a strong relationship between summer temperature from stations in southern Greenland and his determination of surface melt extent based on satellite emissivity observations (which began in 1979). We thought that perhaps such a relationship could be used to hindcast surface ice melt back as far as the temperature observations were available, which turned out to be back into the late 18th century. While researching the topic, we found that the winter NAO index also added useful information on surface ice melt the following summer, and we were able to make use of that information in our statistical model as well. Using a pretty straightforward technique of multiple linear regression, we produced a (near continuous) ‘reconstruction’ of an index of surface melt extent for Greenland from 1784 to 1978. That reconstruction was the guts of our paper. With that reconstruction in hand, we then went on to make some observations (based on a certain set of assumptions), that we thought were interesting about how the current observed period of high melt (and recent trends) fit into that framework. We then went on to speculate on what our results may tell us about the bigger picture, in this case, sea level rise—this speculation was based on a looser set of assumptions (that were also described in the paper). All of this is in the paper that was peer-reviewed and published by JGR. Now, as you all have expressed quite clearly, some of you have other ideas about how things should be interpreted and have made other observations (in some cases based on different assumptions). And when new data come in, even more observations will be able to be made (and assumptions tested). Hopefully our reconstruction provides the framework within which this can take place. It is not an end all and be all, but a tool in which to gauge new observations. The utility of the tool can be judged by the potential users. For those arguing that the tool (the reconstruction) is useless, then there is no reason to even contemplate how the melt during 2010 or any other subsequent year may compare to our determination of the past. For those arguing that the melt from 2010 may alter our observations about how individual and/or multiple year combinations compare to the past (you apparently find the tool to be useful), well, indeed they may. And so too may the years to come. In fact, our paper included this statement in the conclusions “Our reconstruction indicates that if the current trend toward increasing melt extent continues, total melt across the Greenland ice sheet will exceed historic values of the past two and a quarter centuries.” Doesn’t that pretty much fit squarely with what many of you are suggesting? Will the melt during 2010 exceed our melt extent index value for 2007? Possibly (not definitely), and if so, probably not by much. So I don’t anticipate that our conclusions made in the paper will be much impacted. Yes, 2010 may replace 2007 as the year with the greatest melt extent index, but I doubt much else will change substantially. But, I don’t know for sure, as I have stated several times, I have not done the necessary analysis. I think this pretty much sums up the situation from my end. For those of you who have not read the paper and have outstanding issues regarding the technical details, I encourage you to do so, for virtually everything that has been discussed is described in the paper—and, our responses to Jason Box’s review also shed some light on other background/technical issues. Thanks, again, for all your time and interest in our work, and for the discussions we have had. -Chip Knappenberger -
dorlomin at 01:48 AM on 5 May 2011Why 450 ppm is not a safe target
Also the graph shows a difference of around 10% in methane concentrations so not really enough to form a major part of arctic amplification which is abotut 2 to 3 times the warming rate of the rest of the world. -
dorlomin at 01:44 AM on 5 May 2011Why 450 ppm is not a safe target
@muoncounter 5 Also is there any evidence that the imbalance in methane is unusual? With the bulk of the large continents on the Nothern Hemisphere that plus agriculture and industry we would expect a NH bias in concentrations of such a transient gas would we not? -
Tom Curtis at 01:02 AM on 5 May 2011A Flanner in the Works for Snow and Ice
Because, Ken, Trenberth's figure is a figure for how energy is used, not for where it comes from. Therefore it is irrelevant to the discussion. You cannot just pick out one heat sink and say that that determines the total energy flows into and out of a system and neglect the other five (at minimum) heat sinks in the system. Of course, when I say, "You cannot..." I assume I address a reasonable person. -
muoncounter at 00:47 AM on 5 May 2011A Flanner in the Works for Snow and Ice
This seems apropos (and a bit of humor can't hurt this discussion):
source
Before anyone objects, no doubt the bear means that NY's winter TOA insolation is less than that of the Arctic summer, which a quick glance at an insolation graphic verifies.
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michael sweet at 00:34 AM on 5 May 2011Why 450 ppm is not a safe target
Martin, Hansen is at the upper level of scientific predictions. His is not a consensus view (yet). On the other hand, the consensus estimate for sea level rise has gone up about a meter in the last five years. Hansen has generally had high predictions in the past relative to the consensus view. He has often been correct. Hopefully he will be wrong this time. -
Ken Lambert at 23:55 PM on 4 May 2011A Flanner in the Works for Snow and Ice
Tom Curtis #148 Well this takes us full circle Tom. I started off my part in this thread asking why you were highlighting the change incoming energy from decreased albedo and ignoring the outgoing. The NET is what counts. I have quoted Dr Trenberth's numbers for the NET estimated energy uptake from melting Arctic ice plus all Greenland ice plus a 4.2% porion of the global ocean uptake at #143. With these generous totals - we get 4-5E20 Joules/year from Trenberth. Why would you not accept that and call it quits? -
The Skeptical Chymist at 23:49 PM on 4 May 2011Frauenfeld, Knappenberger, and Michaels 2011: Obsolescence by Design?
Hi Chip Thanks for responding to my questions @81 I’m not sure if I am understanding how you did your stats. I had assumed you would have tested if 2007 was within the 95% error range of your model but your comment @112 shows this is not correct. Could you briefly explain how you tested 2007 vs previous years and how these 20 years were chosen? Second I am still curious as to why the abstract of your paper emphasised the duration of the current high melt period vs that from the 20s-60s. Why did you consider duration to be important? Lastly I don’t see the relevance of your point @83, that you (the authors) felt that comparing Greenland melt level in recent years to the 20s-60s was important because the prior melting rate didn’t change sea level rise much. We already know that the current level of Greenland melting is not (yet) a major contributor to sea level rise. Ie: checking the IPCC AR4, they estimate total contribution of Greenland to sea level 1993-2003 as ~0.25mm/year. Ie: A small contribution, but one that is clearly increasing (see the GRACE data). Therefore we never would have expected a similar level of melt to have a big impact on sea level rise from the 20s-60s. So what's the relevance? What confuses me a little is what you then say @83 “This lead us to conclude that if the current melt extent stayed somewhat equivalent to what it was back then, we wouldn’t expect a big jump in the rate of sea level rise as a result of cryospheric processes” What evidence do you have to suggest that the current melt rate will stay somewhat equivalent? Because if it doesn’t then your conclusion becomes somewhat meaningless. And unfortunately for your conclusion, observational data tell us that temperatures and mass loss from Greenland are increasing. So unless you would like to go on the record and predict no future increases in temperature or mass loss/ surface melt from Greenland? I don’t see how your conclusion fits the reality on the ice. -
CBDunkerson at 23:43 PM on 4 May 2011Models are unreliable
trunkmonkey wrote: "The implication of DO/meltwater is profound, because if it is internally driven, we might not know anytinig at a centennial or millenial scale either." Again, this would be observed as a transfer of 'heat' from one hemisphere to the other. Yet all records (i.e. surface thermometers, ocean water temps, satellite readings, et cetera) show that both hemispheres have been warming. Ergo, the observed warming is unquestionably NOT D-O related. And ditto ENSO, PDO, et cetera. These are all examples of energy moving around within the climate system... whereas what we have observed over the past 100 years or so is an increase in energy throughout every part of the climate system. Essentially, your argument is the equivalent of saying that if you pour a gallon of water into multiple different containers it can turn into two gallons of water. In reality it doesn't matter how much you move the water (or heat) around... the amount doesn't change. -
Ken Lambert at 23:39 PM on 4 May 2011Lindzen Illusion #3 and Christy Crock #5: Opposing Climate Solutions
Who is against energy efficiency? Not me. But any method of reducing usage must make economic sense. Use of PV Solar panels with huge taxpayer subsidies is not one of them - and State Govts in Australia are winding back or abandoning such costly schemes. Solar hot water, ground heat pumps, insulation, low energy bulbs all make some economic sense at current energy costs. Some consumption is inelastic - putting up the price won't reduce usage much because there are not any short term alternatives. Diesel or petrol for a transport operator to earn a living is a good example. -
Tom Curtis at 23:28 PM on 4 May 2011A Flanner in the Works for Snow and Ice
I had been preparing a response to Ken Lambert's 143. That response has been delayed primarily because I was trying to track down detailed information of oceanic heat transfer from the sub-arctic to the arctic, and from the surface to the depths in the arctic. However, in light of Lambert's unsavoury characteristic of claiming victory anytime a response delayed, in light of his incapability of admitting error coupled with a determination to score rhetorical points of the errors of others, and in light of his inability to keep even simple concepts straight (as for example the difference between change in incoming energy due to change in albedo (as discussed here) as distinct from the amount of energy used to melt a particular volume of ice (which he repeatedly treats as equivalent), no response will be forthcoming. I find arguments from obtuseness uninteresting - and evidently, that is all that Lambert has to offer this forum. As that is all he has to offer, the rebuttal of any current claim by Lambert can easily be found by perusing previous posts. (In this particular case, one might start by asking just how many heat sinks are their in the arctic. The answer is not three.) -
Arkadiusz Semczyszak at 23:20 PM on 4 May 2011Why 450 ppm is not a safe target
Melting permafrost - is obviously a source of methane. But also sink for around 25% CO2. We do not know what will be the balance sheet. ... However: Melting permafrost is an expanding area of “waterlogged habitats” - a wetlands. And wetlands ... Carbon accumulation in soils of forest and bog ecosystems of southern Valdai in the Holocene, Minaeva et al. 2011.: “The results show that carbon stocks in mineral soils are many times smaller than in waterlogged soils and an order of magnitude smaller than in bog soils. Mineral and bog soils are characterized by similar rates of carbon accumulation averaged over the entire period of their existence. The highest rate of carbon accumulation has been noted for the soils of waterlogged habitats, although this process may be periodically disturbed by fires and other stress influences.” Rising global temperature is contributing to a large number of trees and other vegetation being killed by insect and other pathogen such as Phytophthora, as well as drought and fire. That's not true - diseases and pests have a their enemies and they - usually - limited - strongly - cooling. Anyway ... - general conclusions from recent papers (2011) - for supporters of an environmental catastrophe - are more than “distressing”. The ecological role of climate extremes: current understanding and future prospects, Smith, 2011.: “Arnone et al. (2011) experimentally imposed an extremely warm year on intact tallgrass prairie monoliths from Oklahoma, USA, and found an immediate and large (~30%) reduction in above-ground productivity, driven primarily by the dominant C4 grass species in the system. However, the change in above-ground productivity was well within the range of interannual variability observed for tallgrass prairie, was not persistent over time, and was not accompanied by changes in plant community structure or composition. Similarly, for intact tallgrass prairie in north-eastern Kansas, USA, Smith (2011) shows that over a decade of experimentally imposing an extreme precipitation regime, whereby the number and timing of rainfall events were altered well beyond historical patterns, the resulting reduction in above-ground productivity, although ecologically significant, also fell within the natural range of variation for the system and was not accompanied by substantive changes in the plant community. Finally, with a long-term field experiment where statistically extreme drought events were applied to constructed European grassland communities for five consecutive years, (Jentsch et al. 2011) show a lack of large effects for the majority of the 32 response parameters measured. For example, above- and below-ground productivity remained unchanged across all years of the study ...” -
Martin at 23:05 PM on 4 May 2011Why 450 ppm is not a safe target
I regularly read different climate blogs. Until now, I was under the impression that predictions for a sea level rise by the end of this century were between 0.5 and 2m. That Hansen should predict 5m and so soon (by 2095!! not 2195 or 3095) surprises me. Do you know what the reaction to Hansen is among climate experts (the kind that publish peer reviewed papers on climate change)? Is this a consensus view? -
SoundOff at 22:54 PM on 4 May 2011CO2 is heavier than air
“Pure CO2 is indeed heavier than air and there have even been suffocation deaths caused by volcanic emissions of CO2 many times in human history. The one word answer is wind. The atmosphere is very turbulent (windy) and this turbulence easily dilutes many kinds of gases in the atmosphere and overpowers any small differences in buoyancy [due to molecular weight differentials].” From http://scienceblogs.com/illconsidered/2010/10/is_co2_well_mixed.php There’s a more detailed discussion of this topic at the source: Is CO2 well mixed? -
muoncounter at 22:45 PM on 4 May 2011Models are unreliable
trunkmonkey#364: "we know nothing at a decadal scale" We know this at a decadal scale: Global temperatures are increasing at ~0.15C/decade; northern hemisphere temperatures at 0.3-0.5C/decade. We know of no reasons why that will decrease anytime soon. -
angusmac at 22:28 PM on 4 May 2011Lindzen Illusion #2: Lindzen vs. Hansen - the Sleek Veneer of the 1980s
Moderator@53, "Real life follows physics". OK, for the sake of discussion let us assume that your physics is correct. I compare your adjusted Scenario B with Hansen's original scenarios in the figure below and the following points are evident:- Your adjusted Scenario B reduces the projected temperature anomaly for 2019 from 1.10°C to 0.69°C. Wow! This is very close to the Scenario C value of 0.61°C.
- Actual temperatures follow Scenario C much better for the whole period from 1958 to 2010 than your adjusted Scenario B. Your adjusted Scenario B only catches up with Scenario C in 2010. Thereafter it is slightly higher than Scenario C but follows a similar trajectory.
Moderator Response: [mc] Please restrict image width to 500. -
Bob Lacatena at 22:18 PM on 4 May 2011Why 450 ppm is not a safe target
10, RAYJ, I suggest you repeat your "heavier than air" question on the CO2 is heavier than air thread. Repeat your question about carbon monoxide on the CO2 is not a pollutant thread. But since it's such a simple question, concerning CO2 being heavier than air... the speeds of molecules in a gas are so great that their relative masses are inconsequential when it comes to mixing. There are much more massive molecules in the atmosphere (Argon, atomic weight 40, Krypton, atomic weight 84) and you don't see them all sinking down and blanketing the surface. Concerning CO and CO2, CO is directly poisonous to most living things because it binds directly to hemoglobin and interferes with the absorption of oxygen the blood stream. CO2 is not a poison. It is, however, a greenhouse gas which affects climate. The fact that CO2 is not poisonous is not a rational argument for saying that it is therefore harmless. -
JMurphy at 22:16 PM on 4 May 2011Why 450 ppm is not a safe target
RAYJ, to quickly answer the easiest part of your comment (the last line), Carbon Monoxide (CO) is produced from the partial oxidation of carbon-containing compounds; it forms when there is not enough oxygen to produce carbon dioxide (CO2) Also Exposures at 100 ppm or greater can be dangerous to human health. Carbon dioxide (CO2) is a chemical compound composed of two oxygen atoms covalently bonded to a single carbon atom. It is a gas at standard temperature and pressure and exists in Earth's atmosphere in this state. CO2 is a trace gas comprising 0.039% of the atmosphere. 1% (10,000 ppm) will make some people feel drowsy. Concentrations of 7% to 10% [70-100,000 ppm] cause dizziness, headache, visual and hearing dysfunction, and unconsciousness within a few minutes to an hour. Big difference between the two compounds. -
skywatcher at 22:10 PM on 4 May 2011Frauenfeld, Knappenberger, and Michaels 2011: Obsolescence by Design?
Thankyou for responding, but sorry Chip, you've repeatedly avoided the questions regarding the very bold sea level statement made at the end of the conclusions of FKM 2011. I'll quote it here for those who do not have access to the full text: "However, there is no indication that the increased contribution from the Greenland melt in the early to mid 20th century, a roughly 40 year interval when average annual melt was more or less equivalent to the average of the most recent 10 years (2000–2009), resulted in a rate of total global sea level rise that exceeded ∼3 mm/yr. This suggests that Greenland’s contribution to global sea level rise, even during multidecadal conditions as warm as during the past several years, is relatively modest." Surface melt from Greenland is a small part of the global sea level rise budget. The emboldened part above is a demand that global sea level rise should have exceeded 3mm p.a. half a century ago (!!) in order to satisfy claims about Greenland's sea level contribution, and this is very disingenuous. You were asking the impossible of the data, without assessing the global sea level budget, in order to support an unsupportable conclusion. I did read the justifying statement suggesting that the dynamics in the past 'should' be the same as the dynamics of the present, but that doesn't really cut it for the mass balance of an ice sheet which has been monitored at least in part since the 1950s. Many ice outlets have been observed to have substantially accelerated since then, as you are I'm sure aware, yet you avoid that entirely in the paper as it would render your conclusions invalid. By not considering mass loss by other means (see Philippe's comment as well as my earlier questions), you are not in a position to make statements such as your conclusions on Greenland's mass balance, let alone its contribution to global sea level. Sadly, it really does appear that this paper was indeed out of date before going to press, and, while contributing an interesting historical analysis of surface melt (but not mass balance), contributes nothing about present or future climate change. The shills, regrettably evidentially already including co-author Pat Michaels will claim that it means Greenland melting is nothing to worry about, despite the fact that this conclusion is blatantly not supported by evidence presented in the paper. -
RAYJ at 21:50 PM on 4 May 2011Why 450 ppm is not a safe target
I don't know where to really post this, but, not being a scientist, can someone explain how CO2, being heavier than air, can be consoidered a greenhouse gas. Also much is said about CO2 emissions from motor vehicles. How is it then, if one decides to commit suicide in a car, that it is CO poisoning that is the cause of death. -
mspelto at 21:41 PM on 4 May 2011Frauenfeld, Knappenberger, and Michaels 2011: Obsolescence by Design?
Chip has noted the point that makes their paper irrelevant “The forces acting in concert with ice melt across Greenland to produce higher global sea levels currently, should also have been acting during the extended high‐melt conditions from the mid‐1920s to the early 1960s.” If this assumption is invalid, or is becoming invalid, then our suppositions following there from may need reassessment. This assumption has already been demonstrated to be invalid. The Greenland glaciers did not have this period of rapid acceleration from the mid-1920's to mid 1960's comparable to the current acceleration. We can go back and look at the velocity data in that interval from Carbonnell and Bauer for example, for Jakobshavn as published in a 1989 paper of mine , note Table 1. Note also the associated retreat from 1929-1964 is less than that of 2001-2009 for Jakobshavn and in the case of these large marine terminating outlet glaciers it has been shown retreat is related to velocity. -
CBDunkerson at 21:28 PM on 4 May 2011Why 450 ppm is not a safe target
owl905 wrote: "Why have you written an article about 450ppm CO2 when the issue is 450ppm CO2e?" Which... is one of the points made by the article. As the article notes in the second paragraph, CO2 ppm alone is often used on the grounds that aerosol cooling offsets warming from other greenhouse gases. However, as the remainder of the article then explains, warming from other greenhouse gases is increasing while aerosol cooling is decreasing. It will be interesting to see what sort of limits IPCC 5 suggests. Given that ice loss and sea level rise are progressing much faster than previously estimated I have to wonder if the 2 C 'safe' increase itself isn't out the window... regardless of how we get there. newscrusader's post above makes the same point in greater detail. That said, this may actually be 'good' news in a way. Yes, we have probably already gone beyond the point where we are going to significantly raise sea levels and have planet-wide changes to weather patterns for thousands of years... but this is happening fast enough that it MAY help to wake people up to reality before we get to the point where we vastly decrease agricultural production and/or devastate the ocean ecosystem. -
Chris S at 20:19 PM on 4 May 2011Frauenfeld, Knappenberger, and Michaels 2011: Obsolescence by Design?
Chip @ 119 (and before) "As far as 2010 having a greater melt index value when processed through the methodology described in our paper, I have not done the calculation, so I don’t know. I have reasons to believe it is not as cut and dry a situation that many of you all tend to want to make it." Surely the data are now available to do "the calculation" and demonstrate that it is "not as cut and dry a situation"? To me this is the obvious next step in order to prove that the 2010 melt season really "would not have altered the general nature" of the paper. -
JMurphy at 20:12 PM on 4 May 2011How climate change deniers led me to set up Skeptical Science website
JoeRG, I'm sure John Cook can answer for himself if he feels the need to but I think he makes it clear that the 'ultimate authority' you are referring to (i.e. a single body) is different from the 'ultimate authority' referred to here - the peer-reviewed science. That has no definition as a defining body which determines the truth - rather, as a whole, the peer-reviewed science has congregated around a consensus (in the same way as with regard to Evolution Theory) and this was what John consulted to determine the facts. This is explained, as far as I can see, in the piece above : I made peer-reviewed science the ultimate authority. There's no higher standard than evidence-based research conducted by experts, which is then rigorously scrutinised by other experts. As I began to piece together the various pieces, a clear picture began to emerge. -
chris at 19:41 PM on 4 May 2011Frauenfeld, Knappenberger, and Michaels 2011: Obsolescence by Design?
Chip Knappenberger at 06:30 AM on 4 May, 2011 Since I live in Europe and go to bed 5 or more hours ahead of most of you, your post as been partly answered by others, and maybe we’ve all now learned as much as we need to about this! But concerning statistical analysis I was being a little more specific than is indicated in your point about the IPCC figure; i.e. addressing the assessment of statistical significance in differences between contemporary empirical data with historical data constructed with a model. Your IPCC paleoreconstruction example is a case in point. The 95% confidence range in the annual data in the reconstruction can obviously be defined. However the difference in the instrumental data (apples) with respect to the reconstruction (oranges) is a little misleading when assessed in terms of statistical significance. They don't do this in your example (as your excerpt shows, when addressing comparison of contemporary and paleo data they use a more qualitative, probabilistic statement: "it is likely that the 1990s have been the warmest...."). Obviously one needs to do some sort of analysis, but an apples/orange stats analysis should be accompanied by some careful thought about what’s actually being compared, and in my opinion isn’t suitable for a single bald statement in an abstract. In addition, understanding the relationship between contemporary empirical data and historical reconstruction is deficient without consideration in the context of attribution. With these thoughts in mind I’m mostly curious why the reviewer chose not to consider the stats (perhaps another reviewer did?)! You’ve indicated why you didn’t consider the 2010 melt data, which is quite instructive. It’s left a statement that is factually-incorrect without qualification in the abstract. Still it’s the job of the reviewer(s) to address these points and you seem to have been given a free pass on that! -
newcrusader at 19:15 PM on 4 May 2011Why 450 ppm is not a safe target
At this point 400ppm, sustained over time is not a safe number- as Jim Hansen has said, while in Australia over the winter..... In new research just out, Hansen concludes that at the current temperature, no “cushion” is left to avoid dangerous climate change, and that the Australian government target goals “… of limiting human-made warming to 2° and CO2 to 450 ppm are prescriptions for disaster”. The question Hansen raises is direct and brutal in its implications: is the planet already entering a zone of dangerous climate change? In a draft of a new research paper, Hansen and his collaborator Makiko Sato has opened a new debate about what might be the conditions for a safe climate; that is, one in which people and nations can continue to live where and as they have been, with secure food production, and in a bio-diverse environment. The period of human settlement over the past 10,000 years is known as the Holocene, during which time temperatures and hence sea levels (the two having a close correspondence) have been remarkable stable. Temperatures over the period have not been more than 0.5C warmer or cooler than the mid-line (see chart). The warmest part of the Holocene (the “Holocene maximum”) was about 8000 years ago, and according to Hansen, today’s temperature is about, or slightly above, the Holocene maximum: That is, we are already a little above the Holocene maximum. This matters because Hansen’s and Sato’s look at climate history (paleoclimatology) in this new research finds that it is around this temperature level that the large polar ice sheets start to behave differently. During the Holocene, the Greenland and Antarctic ice sheets have been relatively stable, as reflected in the stability of the sea level. But once substantial melting starts, the loss of heat-reflecting white sea-ice, which is replaced by heat-absorbing dark ocean water, produces an “albedo flip”: Their conclusion is that: “… the stability of sea level during the Holocene is a consequence of the fact that global temperature remained just below the level required to initiate the ‘albedo flip’ mechanism on Greenland and West Antarctica.” The implication is clear that “just above” the Holocene maximum lurks real danger. As Hansen and Sato say: “… the world today is on the verge of a level of global warming for which the equilibrium surface air temperature response on the ice sheets will exceed the global mean temperature increase by much more than a factor of two.” To put it bluntly, we are on the edge of a precipice in terms of large ice-sheet losses and sea-level rises, and there is little “cushion” left: “Polar warmth in prior inter-glacials and the Pliocene does not imply that a significant cushion remains between today’s climate and dangerous warming, rather that Earth today is poised to experience strong amplifying polar feedbacks in response to moderate additional warming.” “… the fundamental issue is linearity versus non-linearity. Hansen argues that amplifying feedbacks make ice-sheet disintegration necessarily highly non-linear. In a non-linear problem, the most relevant number for projecting sea level rise is the doubling time for the rate of mass loss. Hansen suggested that a 10-year doubling time was plausible, pointing out that such a doubling time from a base of 1 mm per year ice sheet contribution to sea level in the decade 2005-2015 would lead to a cumulative 5-metre sea-level rise by 2095. “ Here Hansen repeats his view, first published in 2007 but widely ignored, that a 5-metre sea-level rise is possible. In fact, recent research by Blancon et al published in Nature in 2009, examining the paleoclimate record, shows sea-level rises of 3 metres in 50 years due to the rapid melting of ice sheets 123,000 years ago in the Eemian, when the energy imbalance in the climate system was less than that to which we are now subjecting the planet. We are perhaps already a few tenths of a degree above the Holocene maximum, and the system seems to be in the early stages of rapid change. It is widely expected Arctic sea-ice will be totally lost in summer with a few years to a decade or so, perhaps at less than 1C or warming. Very few scientists think Greenland would be stable in an Arctic with little or no summer sea-ice, and opinion is split as to whether it is past its tipping point already. It is hard to argue that anything above the Holocene maximum (of about 0.5 degrees above the pre-industrial temperature) can preserve a safe climate, and that we have already gone too far. The notion that 1.5C is a safe target is out the window, and even 1 degree looks like an unacceptably high risk. -
JoeRG at 18:25 PM on 4 May 2011How climate change deniers led me to set up Skeptical Science website
Dear John, Reading your excerpt from the Guardian's, for me it's a bit odd. On one hand you say that you think you have a sceptic view, on the other hand you define something as an 'ultimate authority'. In my point of view there is a conflict. As I understand it, an ultimate authority means something like the Pope or a government or general officers at the military etc. That means that only people like believers or soldiers have to follow such an institution without questioning. If not, well, a believer would face the risk to be excommunicated or a soldier would be die soon if he questions the orders. But is this in common with science? Shouldn't it be that way that even scientists have to question themselves, to question their own theories and not only those that might be contradictory? Is it really sceptic when you declare an ultimate thruth -what you definitely do if you state an 'ultimate authority'- what will never be possible because there is no such thing like an 'utimate truth'? To be sceptic means for me to question everything - independent from the meaning behind and regardless of the person that told it. Would you agree to this? -
JMurphy at 18:01 PM on 4 May 2011Could global warming be caused by natural cycles?
johnd, just to be clear, please provide a link to your assertion that "[the El-Nino Index value/La-Nina' is expected to strengthen again and remain negative well into 2012. -
JMurphy at 17:58 PM on 4 May 2011How climate change deniers led me to set up Skeptical Science website
Marcus wrote : "I will say this much, though. Its true that Plimer & Monckton have become slightly *less* important, in the eyes of the Denialist Community, since the start of this year-maybe because their comments are so blatantly embarrassing that even their fellow travelers are beginning to want nothing to do with them." Due, no doubt in large part, to sites like this which pick apart their outpourings and show them up for the propagandist disinformers they really are. Previously, the so-called skeptics used to lap-up whatever they said or wrote because it sounded good (coming as it did from supposed experts, albeit self-described ones) and made their denial seem more science-based. Now that they have been shown to be nothing more than wafflers and purveyors of ill-thought out ideas, some of the so-called skeptics are embarrassed and are now trying to deny all knowledge of these people - especially by pretending that it is sites like these that are giving them publicity, as opposed to the reality that sites like this are reacting to, showing-up and countering the disinformation. Older Australians of a certain political persuasion still seem to lap-up their nonsense, though... -
RSVP at 16:34 PM on 4 May 2011Why 450 ppm is not a safe target
From the article, it sounds like ensuant drought, famine and flooding should take care of all these problems quite effectively. -
Marcus at 16:17 PM on 4 May 2011How climate change deniers led me to set up Skeptical Science website
"Other than say - well done John, one could suggest that disagreement is not denial, and that there are valid reasons to doubt some of the supporting evidence for the AGW case." Hmmm, I'd say the only *valid* reasons to doubt the supporting evidence would be if (a) the evidence was obviously flawed or (b) if the Contrarian Camp were able to come up with a better hypothesis to explain the observed warming trend of the past 60 years, in general, & the last 30 years in particular. Neither seems to be the case-the evidence is as strong as it was over 100 years ago & the Contrarians have yet to come up with an opposing hypothesis which is able to stand up to scrutiny. What I see from Contrarians, most often, are attempts to discredit the scientific community, wacky conspiracy theories, attempts to downplay the future seriousness of the problem and attempts to overstate the possible economic consequences of taking action. None of which I'd define as *valid* reasons for doubting scientific *fact*-just a desperate bid to muddy the waters & delay action for as long as possible. -
owl905 at 15:59 PM on 4 May 2011Why 450 ppm is not a safe target
Why have you written an article about 450ppm CO2 when the issue is 450ppm CO2e? Off the cuff, CO2 is into 'the red zone' at about 425ppm with the rest coming primarily from increases in CH4. Pre-Ind 2009 Increase Forcing wm2 C02 280 ppm 388 ppm 108 ppm 1.46 CO4 700 ppb 1745 ppb 1045 ppb 0.48 With CO2 concentrations growing at about 2ppm per year, it's less than 20 years to be 'in the red zone'. But even the 2 ppm growth rate will be surpassed once the current global recession gives way to new global growth. -
Jason at 15:57 PM on 4 May 2011Video and podcast about confusing the hockey stick with the 'decline'
"Baseload power" is a concept that exists only because certain technologies are inflexible, not because it reflects what is actually required. The demand for power fluctuates through a range of about 2.5:1. In other words, the peak power requirement during a hot sunny day in a place like California is 2.5 times greater than in the middle of the night in winter. Coal-fired power stations and nuclear powerplants really like a constant output, both for technical reasons (it's difficult to change the output for both plant types) and economic reasons (coal and nuclear powerplants have relatively high capital costs, relatively low fuel costs, and finite lifetimes, so getting a good cost per kWh generated depends on generating as much as possible during the lifetime of the plant). Because of this mismatch between supply and demand we have "peaking power generators", like gas, that follow the load and produce more power when the demand is high and less when it is low. Peak power generators have much higher fuel costs compared to capital costs and they pay for themselves by only selling power when the price is right. This is why many utilities offer pricing schemes where they charge more for power during peak periods and much less for power during off-peak. The forecast expansion of nuclear was also the driving force behind expanding pumped hydro capacity a few decades ago (see Dinorwig power station for an example) so it's a mistake to think that energy storage is an issue for renewables only. In fact, with solar power, because the generating behaviour more closely correlates with demand, the gap between what is being generated and what is being demanded is less, and peaking power generators are actually required less often when using solar than when using so-called "baseload power generators" like coal and nuclear. Nevertheless, there is no reason why solar and wind can't displace a large percentage of "baseload power" generators with load-following generators filling the gap in exactly the same way they do now, and as storage is added to the system (molten salt, pumped hydro, etc.) peaking power will be used less and less often. Of couse, we have a long way to go before this becomes an issue -- until solar and wind penetration exceeds 20% of the grid, we can just use "grid storage" (i.e., use them to displace other sources of power), which is extremely efficient because you're not really "storing" energy at all, you're simply avoiding the generation of energy you don't need. Here is a report from Germany on the reduction in the cost of electricity that wind power resulted in that more than compensated for the subsidy paid to have that wind power added: Merit Order Effect The reason for the cost reduction was that although wind power wasn't the cheapest energy source available, wind power providers will dump all the power they can generate onto the market whenever they can -- there's no benefit to them in turning off turbines when the price gets too low because there's no "fuel" to save in doing so. The availability of wind power electricity at whatever-price-was-going meant that customers avoided buying power from peak power generators using more expensive technology when there was enough wind for them to do so. -
Philippe Chantreau at 15:33 PM on 4 May 2011Frauenfeld, Knappenberger, and Michaels 2011: Obsolescence by Design?
I find the paper of seriously limited interest. Since it does not consider calving, it does not address mass balance, which is the really important metric. The main focus appears to be on statistics, while ice sheet dynamics hold many areas of inquiry that are far more interesting than the mere descriptive numbers. It is not very useful for much of anything. As with most statistical approaches, the lack of the most recent data in the analysis makes it even less useful. I'm sure Pat Michaels can throw around a lot of sound bites from it that are technically true within the frame of the paper, and that satisfies him. After all, his main line of work seems to be PR. However, for those who really study ice, like Dr Box or Mauri Pelto, it offers next to nothing toward an improved understanding of the physical reality. Much ado about nothing, really. -
Ken Lambert at 15:21 PM on 4 May 2011How climate change deniers led me to set up Skeptical Science website
Albatross #72 I invited all to the Flanner thread at #64. Tom Curtis has not responded to my posts there since 30th April. He then places a post here at #65 which should have been on the Flanner thread. Direct your criticism to Tom Curtis. If this thread has a clearly defined topic, it is about the personal musings of our host John Cook on what motivated him to start up the site. Other than say - well done John, one could suggest that disagreement is not denial, and that there are valid reasons to doubt some of the supporting evidence for the AGW case. -
Albatross at 15:00 PM on 4 May 2011How climate change deniers led me to set up Skeptical Science website
Marcus @77, You can add Pat Michaels and Christy to that list. -
Albatross at 14:58 PM on 4 May 2011Frauenfeld, Knappenberger, and Michaels 2011: Obsolescence by Design?
Hello Chip, Thanks for your post @119. You did not refer me to #95 before, you referred me to #112. Regardless, I'm afraid that you insist on continuing to evade the point. Quite frankly your "strong belief" that including the 2010 data would not make a difference to your conclusions is irrelevant, and unscientific to boot. What it boils down to is this. The validity of your argument now rests on you demonstrating qualitatively to everyone that the melt stats for 2007 exceeded those for 2010. While what you believe may be correct (albeit unlikely, given other people's findings on 2010 melt versus other years), you have not demonstrated that despite having ample opportunity to do so. Rather, you admit that you are making a claim without having done the analysis and choose to cite "belief" instead. Not a compelling argument, so thank you for confirming that. -
KR at 14:55 PM on 4 May 2011How climate change deniers led me to set up Skeptical Science website
Marcus, johnd - Here in the States, we don't read the Australian at all. Washington Post? CNN? The Guardian? Yep. But not the Australian. That's "local" news for a locality far from here. That said, Monckton has shown up in front of Congress for the Kabuki theater that is the US Congress (which I state as someone for whom Congress is local news). When he does, we in the States make appropriate noises in response. Usually gagging. --- For me, looking at the world through the clearest glass I can find is important for my personal integrity. Logical fallacies, rhetoric contrary to facts, and lying for self-interest are maddening to me. I have the greatest respect for John Cook for putting so much effort into this website. I believe that it has had an effect - clearly delineating the science, and hopefully killing off some of the counterfactual rhetoric. I hope, in my own small way, to help contribute to this effort for some time to come. -
Marcus at 14:53 PM on 4 May 2011How climate change deniers led me to set up Skeptical Science website
I will say this much, though. Its true that Plimer & Monckton have become slightly *less* important, in the eyes of the Denialist Community, since the start of this year-maybe because their comments are so blatantly embarrassing that even their fellow travelers are beginning to want nothing to do with them. That certainly shouldn't allow the Denialist Movement to try & rewrite history, & pretend like Monckton & Plimer weren't ever their "star performers". As I said, though, some elements of the Denial community *still* view Monckton & Plimer as heroes of their movement. Last point, John, I personally *rarely* mention Plimer or Monckton unless they're first mentioned by one of the Denialists. Given that it was *you* & Ken who brought them up in this thread, then that surely suggests its *you*-& not us-who are fixated on them. -
pbjamm at 14:53 PM on 4 May 2011How climate change deniers led me to set up Skeptical Science website
By the way Ken Lambert, Your last comment on the Flanner thread was May 2nd while your last Flanner based comment here was May 4th. If you really intended to invite people over there you would post something to the effect of "please see my comments here" with a link to your latest comment. And so I don't add to your feelings of persecution, Tom Curtis should be doing the same. -
scaddenp at 14:46 PM on 4 May 2011Models are unreliable
Slight difference. We can't predict ENSO, PDO,AMO in models. These internal variabilities exist in models. You can certainly run a model and get PDO index out of it. However, you cant initialise a model to predict them. I don't of any paper which puts a case for DO being internally driven. Do you? Everything has physical causes. -
Marcus at 14:45 PM on 4 May 2011How climate change deniers led me to set up Skeptical Science website
"Is Monckton that important a figure to you that you are now actively recommending others should read certain sections of certain newspapers just to keep up with the latest news about him?" The point, John, is that whether you choose to accept it or not, the majority of your fellow Denialists clearly see him as an important figure-to the extent of viewing him as an "expert" in the field-otherwise, why would they give him so much air-time? Talk-back radio, Right Wing Newspapers (like The Australian), Fox News & the US Republican Party *all* give him & his ilk plenty of lime-light, hardly something they'd do for someone they considered inconsequential. This, of course, speaks volumes about the dearth of *real* experts that exist within the Denialist Camp. JMurphy's link was simply to show that, in spite of your rampant denial, The Australian still views him as a very newsworthy figure. That point, like most others, appears to be completely lost on you however. -
KR at 14:44 PM on 4 May 2011Models are unreliable
trunkmonkey - So, a little uncertainty, and we know nothing? That's not a reasonable statement, trunkmonkey. I don't think that's been established anywhere. Tamino has demonstrated how to look at ENSO and other local variations, and remove their influence. The results? The warming we expect from the CO2 we've added, at the trends we expect from the physics. A wee uncertainty is reason for resolving how much we know despite the uncertainty, not reason for throwing up our hands and giving up. That said, an overturning of the thermohaline circulation due to increased fresh water would be a large change in climate state. But that hasn't happened for a long time, and won't happen unless due to our influence, barring major changes in natural forcings which are well out of what we've seen in millenia. -
pbjamm at 14:42 PM on 4 May 2011How climate change deniers led me to set up Skeptical Science website
Ken Lambert@71 Your comment @2 was an off topic complaint about moderation and a claim of victory on the Flanner thread. Nothing at all to do with the creation of SkS or why you come here. This was a fairly successful redirected of this thread into a subset of Flanner. Quite frankly I think the moderators should delete *ALL* the Flanner based comments (including my own) as they are 100% off topic. -
Marcus at 14:37 PM on 4 May 2011How climate change deniers led me to set up Skeptical Science website
"Marcus at 18:24 PM, you are confirming my point." How so? I don't exactly seek out mentions of Monckton, Plimer or any of those other hard-core Denialists in The Australian, they're there in Black & White in every single Op Ed piece that is devoted to the issue of Climate Change. The Editorials also frequently make mention of these "stars" of the denial movement, as do many of the journalists who work for The Australian. If you've missed these frequent mentions, then I can only suggest that its because you're trying to read the *braille* version of the newspaper. -
Chip Knappenberger at 14:32 PM on 4 May 2011Frauenfeld, Knappenberger, and Michaels 2011: Obsolescence by Design?
Albetross, Since you think that repeating things seems to help clarify things, I'll go ahead and repeat what I wrote in comment 95 concerning the melt extent in 2007 and 2010...Granted, incorporating the melt extent for the summer of 2010 into the methodology as described in our paper may have required a few minor tweaks to some of the wording (and a few specific numbers). But, by and large, as I have said many times, I strongly believe (although I have not done the analysis) that the changes would not have altered the general nature of our conclusions (as we explained to the JGR editor).
and in comment 112 concerning the same thingAs far as 2010 having a greater melt index value when processed through the methodology described in our paper, I have not done the calculation, so I don’t know. I have reasons to believe it is not as cut and dry a situation that many of you all tend to want to make it.
So I guess now that we've both repeated ourselves, the topic should be about as settled as it is ever going to get until (when/if) our analysis gets updated. Agreed? -Chip
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