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JMurphy at 03:30 AM on 31 May 2011The Critical Decade - Part 1: The Science
Ken Lambert wrote : "This cannot mean anything else than SLR slowing or decelerating - not accelerating." That is so obvious, if you're a so-called skeptic, is it not ? In fact, to take the 'obvious' further, into temperature increases, it is 'obvious' that while temperatures increase as Spring moves into Summer, eight or nine or ten days of cooler than average temperatures mean that temperatures are slowing or decelerating - not accelerating. It cannot mean anything else...if you're a so-called skeptic. -
damorbel at 03:29 AM on 31 May 2011Of Averages and Anomalies - Part 1B. How the Surface Temperature records are built
Re #14 MarkR You wrote:- "at 1200 km separation the temperature change correlation coefficient dropped below 0.5, so used 1200 km as their cut off for weighting." For a start a correlation coefficient of 0.5 is rather low. Also it is only related to climate change of any cause, the figures are just as valid for Svensmark's cosmic ray theory as for CO2. As far as HL87 is concerned, it is about 'filling in for missing stations' A feature of historical climate change are the ice ages; these were times when large sheets of ice formed over the land masses of the Northern Hemisphere. During the ice ages Antartica and the Southern Hemisphere did not acquire large sheets of ice, substantially beyond what they have now. The meaning of this being that climate change is not correlated over the Earth's surface. -
Dikran Marsupial at 03:26 AM on 31 May 2011The Critical Decade - Part 1: The Science
camburn@78 Looking at the number of times the paper has been cited and in what context is usually a good start. Looking at the publication record and expertise of the authors is another. It is always a good idea to apply some skepticism to any new paper, because until there has been time for the research community to digest and either refute, take up or ignore the ideas it puts forward, we are not in a good position to judge its value. This is especially true of papers adopting a controversial stance, they generally turn out to be wrong - for every Galileo, there are thousands of scientists who are simply mistaken. This happens in all fields, not just climatology, I can tell you for certain there are loads of dud papers that get published every year on statistics. Generally their fate is that they are ignored and receive no citations. Most of the papers that form the underpinnings of AGW theory have been in print for a long time, have been widely discussed/criticized, and have withstood the criticism. That means they are very likely (but not certain of course) to be correct. -
Paul D at 03:23 AM on 31 May 2011An Interactive History of Climate Science
Daniel@4 one of the ideas for a future version is to have a search option, so that you could select a topic and it will display the number of papers in each year for that topic in the appropriate 'argument'. -
DaneelOlivaw at 03:18 AM on 31 May 2011An Interactive History of Climate Science
I'm not sure about that categorization. I think that what's relevant is how many papers agree with the basic consensus that the Earth is warming and we are the primary cause. Many of the skeptic arguments wouldn't undermine that conclusion even if true. Overall I think that Oreske's method is simpler, clearer and more relevant to the discussion. If you want tu pursue this type of classification, maybe you could filter by argument. So the graph could tell you, for each argument, how many papers are for, and how many against. -
Rob Honeycutt at 03:07 AM on 31 May 2011Are you a genuine skeptic or a climate denier?
RW1 @ 21... "Not more than about 1 C and probably more like 0.5 C or less." You original question was, "What camp does this put me in?" This would clearly put you in the denier camp because to accept that proposition you have to deny a wide range of existing research that suggests otherwise, all consisting of papers which appropriately apply scientific skepticism. -
Camburn at 03:02 AM on 31 May 2011The Critical Decade - Part 1: The Science
And Albatross: How do you know your papers are correct verses other papers written by distinguished scholars? -
Camburn at 03:01 AM on 31 May 2011The Critical Decade - Part 1: The Science
Albatross: I can only suggest that you read this paper. Some of us contrarians like to try and view SLR in its entirety.Moderator Response: [Dikran Marsupial] hot linked paper -
dana1981 at 02:57 AM on 31 May 2011Are you a genuine skeptic or a climate denier?
RW1 @21: claiming sensitivity is just 0.5-1°C for doubled CO2 (3.7 W/m2 forcing) denies the massive body of research using many different lines of evidence that all consistently shows otherwise. Just as one example, it's nearly impossible to explain the ~5°C warming between glacial and interglacial period if sensitivity is that low. Also see the forthcoming Christy Crock #6: Climate Sensitivity which is due to be published sometime in the next week. -
Dikran Marsupial at 02:54 AM on 31 May 2011Can we trust climate models?
Charlie A@60 In addition to Tom Curtis' comment (which is spot on), the errors depicted in your graph are dominated by high-frequency annual variations, something that no model would claim to be able to predict. However, there is no long term trend in the errors, which shows that the models predict climate (which is what they do claim to be able to do) rather well. I am assuming that the GISS model E prediction is actually the mean of an ensemble of model runs (comparing the observations with a single model run would be an obviously unfair test). If this is the case, you appear ignorant of the fact that the models attempt only to predict the forced component of the climate. Whereas the observations consist of the forced component and the effects of unforced natural variability (which the averaging of the ensemble is designed to eliminate). Thus anyone with a sound understanding of what the model project means would not expect there to be a close match on a (say) sub-decadal basis, as on that timescale unforced variability dominates. -
Albatross at 02:42 AM on 31 May 2011Are you a genuine skeptic or a climate denier?
The "Lukewarmer" position is a disingenuous cop out, and allows one to cherry pick one's way thought he science and debate. It also allows one to play games as has been so effectively done by some people like Steven Mosher. I could claim to be a "lukewarmer" because my reading of the science leads be to think that climate sensitivity is close to +3 C rather than say + 5 or +6 C for doubling CO2. Advancing that as a reason to claim that there is nothing to be concerned about or as a reason to not dramatically reduce our GHG emissions is not acceptable though. And it doesn't make the ocean acidification problem go away. Moreover, claiming to be a "lukewarmer" only goes to show that the former deniers of AGW and 'skeptics' have painted themselves into a very tight corner, so their only way of trying to save face and appear to be reasonable is to claim to be a "lukewarmer"...well sorry, people are not going to buy into that type of weaseling. -
michael sweet at 02:39 AM on 31 May 2011Are you a genuine skeptic or a climate denier?
RW1, Since the world has already increased in temperature by more than 0.5C and we are not even near doubling yet, how do you explain current warming with a 0.5C sensitivity? Do you expect it to cool for the next two decades? -
Tom Curtis at 02:36 AM on 31 May 2011Can we trust climate models?
Charlie A @60, the GISS model is not updated annually with real temperatures. Consequently to do a proper comparison with the "skeptic model" you should not provide it with that data either, ie, you should program in the initial conditions, predict 1881 temperatures from that, then predict the 1882 temperatures from the model prediction, and so on. The result will, of course, be a straight line with all temperatures predicted as equalling those of 1880 - a much worse performance than that of the GISS-E. -
Charlie A at 02:26 AM on 31 May 2011Can we trust climate models?
PaulFP @59 "Even climate skeptics use models but, for many, the model is simply that next year will be the same as last year. That sort of model is indeed unreliable." While the snide humor may be appealing, your observation is wrong. The GISS-E model run for AR4, using the actual observed forcings for the period 1880-2003, does a poorer job of predicting the GISS global average temperature anomaly over that period than the simple "next year will be the same as last year". The GISS-E model is worse in both correlation factor and in the rms error. RMS error for both the "next year same as this year" and the GISS-E hindcast using actual forcings were around 0.15C, with the GISS-E model being slightly higher. Red is GISS-E errors vs GISS anomaly, black is "skeptic model" error. -
tallbloke at 02:16 AM on 31 May 2011Climate Change Denial book now available!
DSL@65 "You suggested SoD work on Miskolczi. SoD did" Yes I know. I have been in contact with Miklos Zagoni by email to pass on to Ferenc an interesting correlation I found between specific humidity at the tropopause and solar activity. Along with my work on the solar activity level - ocean heat content coupling, it explains why the Sun has been able to simultaneously cause the cooling of the stratosphere and warming of the ocean in the late C20th. No tropospheric hotspot required. This forms part of my own tentative hypothesis accounting for some as yet unquantified proportion of climate variability. Your comment below that link seems to be a kind of 'all or nothing' argument. My view is that many different factors are involved in climate variability, and that the proportions of the individual contributions are not as well constrained as the IPCC reports say they are. My aim is to make a contribution by helping to better determine the solar contribution, and discover the underlying cause of solar variability, in order that testable predictions can be made. Working on that doesn't leave me with enough spare time to worry too much about the ephemeral arguments from people on either side of the debate. Moreover I don't feel the need to get involved in their arguments because I am already doing all I can to lead a low impact lifestyle. It is my belief that actions speak louder than words in encouraging people to follow good examples and practices. -
les at 02:16 AM on 31 May 2011Climate Change Denial book now available!
67 - albatros. I think you over rate him. Note how 64 & 65 are so clearly on the money that all he can do is the switcheroo. Sure, best to change the subject before someone asks the discussion on his bog reflects science being done to the highest standards. Sorry - that's trolling 101. Credit where credit is due, the "psychologicalising" gambit could have gone somewhere... in more capable hands. But this is just more bargain-basement troll stuff. I said it before, SkS is in an awful state as judged by the poor quality of the trolls it's attracting. Feel free to delete this. -
Nick Palmer at 02:03 AM on 31 May 2011Are you a genuine skeptic or a climate denier?
To Humanity rules @ #5 and #6 (and any other lukewarmers): In reality, the only argument that those who want to do little or nothing to reduce emissions of greenhouse gases have that makes any sense is if the climate sensitivity is much less than the majority scientific view says it is. The whole of the bizarre cacophony of conflicting views of the rest of the denialist/sceptic crew is justly deserving of the scorn that it attracts for its sheer wrongness. If this was just like a scientific debate about, say, how many dimensions string theory needs then the "low climate sensitivity" crew would be, if not welcomed with open arms by the "consensus", at least respected for their different opinions... but it is not. In the case of climate science it is not just academic reputations that are at stake - it is the future living conditions for humanity, not to mention all the eco-systems that support life as we know it. There is no simple experiment we can run to directly determine the short term/long term climate sensitivity; it can only be done by inference and deduction. If we had a time machine to go back 100 years multiple times so we could try altering emissions to see the varying effects then we could nail it, but we don't. As we are stuck with inference/deduction to work out whether what we are doing to the atmosphere will end up with benign, no-change, irritating, dangerous or catastrophic results, the political/industrial/lifestyle strategies that we should develop from the knowledge we have cannot wait for absolute certainty as to the outcome. It comes down to risk assessment. What is the best strategy faced with Dirty Harry's Magnum when you don't know for sure whether there are any bullets left in the chamber? Rush him and find out that he was bluffing, steal his winning lottery ticket and live happily ever after? Slim chance. As this is an analogy for the climate system, there isn't just one possible bullet but an uncertain number, each of a differing degree of danger plus you don't know how good Harry's aim is. Taking a chance that your belief is correct is rather foolish when the odds are probably against you, but you do have a perfect right to risk your own life and future. If it was just you - nobody else around - no web of life to disrupt - I would say let your fossil fuel emissions rip and have fun. What you don't have is a right to risk everybody else's lives and futures in the service of your beliefs - that is why it is irresponsible, bordering on a crime against humanity, for denialists and lukewarmers alike to muddy the waters with their beliefs and thereby potentially fool the voting public that adopting those beliefs might be a sensible strategy. -
dhogaza at 01:58 AM on 31 May 2011Are you a genuine skeptic or a climate denier?
RW1: since you asked, you're a denialist. -
Alexandre at 01:57 AM on 31 May 2011An Interactive History of Climate Science
Oh. Of course. Thanks Mark! -
Tom Curtis at 01:52 AM on 31 May 2011Climate Change Denial book now available!
tallbloke @66, I need not remind you that the mean climate state is not the only means used to estimate climate sensitivity. Granted that range of uncertainty of measured TOA energy balance is large, and that means climate sensitivity estimates based on the recent climate state may be significantly smaller than previously thought (or larger, as uncertainty cuts both ways). But that does not effect other methods of estimating climate sensitivity, and they continue to show climate sensitivities in the IPCC range. So, taking all evidence into account, it is highly unlikely that climate sensitivity will below 2 degrees per doubling of CO2 as you claim. If you have five or six radar stations tracking the position of an aircraft and one other that cannot track it, the correct conclusion is not that you are almost completely in the dark about its location, but that your error on the location may have slightly increased. Your response, however, seems to be the equivalent to turning of the monitors on the six tracking radars, then calling out the search parties. -
MarkR at 01:50 AM on 31 May 2011An Interactive History of Climate Science
You have to scroll down, Alexandre! -
RW1 at 01:49 AM on 31 May 2011Are you a genuine skeptic or a climate denier?
Albatross (RE: 20), "So pray, please enlighten us how much the planet will warm for doubling CO2. A number please." Not more than about 1 C and probably more like 0.5 C or less. -
Albatross at 01:46 AM on 31 May 2011Are you a genuine skeptic or a climate denier?
RW1 @19, Here we go ;) So pray, please enlighten us how much the planet will warm for doubling CO2. A number please. -
Alexandre at 01:46 AM on 31 May 2011An Interactive History of Climate Science
Great resource, much like the good Gapminder style. I moved the mouse over the circle, and the amount of papers on that year appeared. But when I clicked on it, nothing else happened. Is it just me? -
RW1 at 01:43 AM on 31 May 2011Are you a genuine skeptic or a climate denier?
Albatross (RE: 17), "Science site, please be more specific. Also, going by the huge volume of comments made you elsewhere on this site, you actually do appear to contest that doubling CO2 will cause about 1.1 C of warming." This is a hypothetical amount that assumes neutral or no feedback. Also, the direct warming from 3.7 W/m^2 is only 0.7 C - not 1.1 C. The 0.4 C comes from adding on the net transmittance to space of about 0.6 or 60%. The problem is this amount already accounts for the lion's share of the feedbacks in the system from decades, centuries and even millenia of solar forcing. -
Albatross at 01:43 AM on 31 May 2011Climate Change Denial book now available!
Everyone, @57"since there is an expressed wish that I "be quiet" here. " Conspiracy, conspiracy!! (/sarc). I warned you guys. Person in question will twist, distort and misrepresent your position and the thread could go on for days (think Poptech). And as noted by Les, any moderation will be framed as censorship or something along those lines. So you are damned if you do and damned if you don't. Beware, they may also be here to incite people so that they can quote mine...."those mean and intolerant SkS people, and they call themselves a 'science' site". Yes silly, but believe it or not folks do this sort of thing, so we can't ignore it. Are we debating denial still or Haydn and Cook's book, or are we entertaining the musings of a D-K? I would urge strict moderation to keep this thread on topic. People who disagree with what Haydn and Cook have written need to write clear and concise arguments, and state their position clearly. Feel free to snip potentially offensive and/or off-topic bits. -
newcrusader at 01:30 AM on 31 May 2011Are you a genuine skeptic or a climate denier?
#16 it makes you a skeptic- earth has warmed far more in the past- the PETM and the Eocene Optimum. 5-7 degrees C by the same carbon forces- light carbon and methane- the natural geologic forces where much slower- but the end result was that the same GHG back then (and today) pushed up temperatures. Today we are bringing carbon into the atmosphere at a magnitude (rate) unknown in the past something on an order 10,000 times as fast. Your failure to understand this concept is perplexing. -
Albatross at 01:24 AM on 31 May 2011Are you a genuine skeptic or a climate denier?
@16, "man is adding it to the atmosphere and this will likely lead to some warming" Science site, please be more specific. Also, going by the huge volume of comments made you elsewhere on this site, you actually do appear to contest that doubling CO2 will cause about 1.1 C of warming. You need to read Dana's post @15, your "profile" perfectly fits that described by Dana. -
Albatross at 01:21 AM on 31 May 2011The Critical Decade - Part 1: The Science
Now given that contrarians like to focus on regional trends. Some new science that is not exactly reassuring. From ScienceDaily on a new paper by Howat et al. (2011) [in press], "In the last decade, two of the largest three glaciers draining that frozen landscape have lost enough ice that, if melted, could have filled Lake Erie. The three glaciers -- Helheim, Kangerdlugssuaq and Jakobshavn Isbrae -- are responsible for as much as one-fifth of the ice flowing out from Greenland into the ocean. "Jakobshavn alone drains somewhere between 15 and 20 percent of all the ice flowing outward from inland to the sea," explained Ian Howat, an assistant professor of earth sciences at Ohio State University. His study appears in the current issue of the journal Geophysical Research Letters." And talking of Howat, more "cheering" news, "A dramatic thinning, retreat, and speedup began in 1998 and continues today. The timing of the change is coincident with a 1.1°C warming of deep ocean waters entering the fjord after 1997. Assuming a linear relationship between thermal forcing and submarine melt rate, average melt rates should have increased by ∼25% (∼57 m yr−1), sufficient to destabilize the ice tongue and initiate the ice thinning and the retreat that followed." And yet more "cheering" news from the Arctic and Antarctica in another paper by Thomas et al. (2011), "Ice discharge from the fastest glaciers draining the Greenland and Antarctic ice sheets – Jakobshavn Isbrae (JI) and Pine Island Glacier (PIG)– continues to increase, and is now more than double that needed to balance snowfall in their catchment basins. Velocity increase probably resulted from decreased buttressing from thinning (and, for JI, breakup) of their floating ice tongues, and from reduced basal drag as grounding lines on both glaciers retreat. JI flows directly into the ocean as it becomes afloat, and here creep rates are proportional to the cube of bed depth. Rapid thinning of the PIG ice shelf increases the likelihood of its breakup, and subsequent rapid increase in discharge velocity. Results from a simple model indicate that JI velocities should almost double to >20 km a−1 by 2015, with velocities on PIG increasing to >10 km a−1 after breakup of its ice shelf. These high velocities would probably be sustained over many decades as the glaciers retreat within their long, very deep troughs. Resulting sea-level rise would average about 1.5 mm a−1." The contrarians and 'skeptics' posting here are in deep, deep denial. Fascinating and scary at the same time. -
RW1 at 01:13 AM on 31 May 2011Are you a genuine skeptic or a climate denier?
I believe that CO2 is a GHG, that man is adding it to the atmosphere and this will likely lead to some warming. However, I think the 'enhanced' warming of 3 C cannot be supported. What does that make me? -
ptbrown31 at 01:07 AM on 31 May 201110 Indicators of a Human Fingerprint on Climate Change
I too feel that Skeptical Science is overselling DTR changes as a greenhouse signature (it is probably an ANTHROPOGENIC signature - not the same thing). I have never seen a paper about observed changes in DTR that attributes it to an enhanced greenhouse effect. Instead every paper that I have seen (including the ones listed on skeptical science) attribute the DTR changes to a suppression of daytime solar radiation - probably from anthropogenic aerosols. I think that the problem with CBDunkerson's argument above is that nighttime minimum temperature is not independent from daytime maximum temperature. If radiative cooling to space is suppressed, and the nighttime minimum temperature increases, then as soon as the sun comes up the daytime warming starts from this new warmer temperature. If this is the case then the daily max should increase as well. One other thing. In the IPCC AR4 summary for policy makers, it says this: "A decrease in diurnal temperature range (DTR) was reported in the TAR, but the data available then extended only from 1950 to 1993. Updated observations reveal that DTR has not changed from 1979 to 2004 as both day- and night-time temperature have risen at about the same rate. The trends are highly variable from one region to another." If Skeptical Science wants to claim that DTR changes are due to an enhanced greenhouse effect then they are cornering themselves by making it necessary to come up with an explanation for why DTR hasn't changed in recent decades. -
Albatross at 01:01 AM on 31 May 2011The Critical Decade - Part 1: The Science
Dear Contrarians, Look at the graph from Chruch and White (2011), I mean actually look at it, now absorb. Or will your preconceived ideas not permit that image to be processed and absorbed by your brains? Also, remember how those in denial about AGW cherry picked 1998 in the global temperatures (some still do) to delude themselves that AGW had stopped....well they are now doing the same using sort of cherry picking the global Sea-level data. And you know what folks, we can continue playing this game come 2100, "Ooh GSL rise slowed the last 5-10 yrs", meanwhile global sea levels will have in all likelihood risen by more than 1 m from current levels. In fact estimates, keep getting revised upwards, not downwards. You are in denial contrarians. Further, your tricks of deception are growing very old. They might work to continue deluding yourself, but don't expect others to be fooled. Moderators, the contrarians , despite being shown the correct data and warned do look at the big picture on Arctic sea ice, Greenland ice mass and now GSL. My suggestion is that future posts which continue to cherry-pick, ignore the science and the facts be snipped. -
tallbloke at 00:56 AM on 31 May 2011Climate Change Denial book now available!
Skywatcher@63 "Uncertainties about climate change do not, from a scientific perspective, include a range of climate change where there will not be serious consequences for modern human society from coastal swamping, extreme weather and poor food security." The range of uncertainty on measurement of the top of atmosphere energy balance is around three times the size of the claimed theoretical signal from co2 plus alleged positive feedbacks. Kevin Trenberth knows this, which is why he worries about the location of the theoretical 'missing heat'. Sensitivity may therefore be well below the range you state. -
dana1981 at 00:50 AM on 31 May 2011Shaping Tomorrow's World After One Month
I may be biased, but I think Shaping Tomorrow is a very interesting site. More discussion about climate solutions is very important at this point.Response: [JC] It is a great site. Good looking authors too! :-) -
dana1981 at 00:47 AM on 31 May 2011Are you a genuine skeptic or a climate denier?
dorlomin - I think all deniers accept some evidence, but deny other bits. I suppose the reasonbleness of the denier depends on where they draw the line. Like HR's example of Spencer accepting a fair amount of the evidence, but he denies other bits (not just limited to sensitivity). Perhaps denial is a spectrum where what they all have in common is denying some aspect of the evidence so they can oppose taking action to solve the problem (which Spencer certainly does). -
skywatcher at 00:40 AM on 31 May 2011Of Averages and Anomalies - Part 1B. How the Surface Temperature records are built
Some serious fudging of the (non)issues here by damorbel. For comparison between the Sun's output and planetary temperature, there's a handy page on this site called It's the Sun. If you don't think that there's a relationship between temperatures of stations within 500km or 1000km, or stations of different elevations, clearly you haven't ever done any temperature reconstructions, understood lapse rates, or looked at the data. There's a handy temperature reconstruction that does not extrapolate to cover regions of missing data, it's done by those friendly folks at CRU and is the HADCRUT3 dataset. It shows just the same pattern of warming as GISS. Satellite data, done by those friendly folks at UAH, also shows just the same pattern of warming. Though it may "seem to you to be tenuous in the extreme", fortunately there are some clever people out there (including Hansen et al), both professionals and bloggers, who have done the maths and determined that your assertion of limited correlation between stations, supported by nothing more than handwaving, does not stand up to scrutiny. See many articles elsewhere on this site for why the 40% extra CO2 is the most important driver of present climate, concentrate on things like the fingerprints of CO2. -
MarkR at 00:35 AM on 31 May 2011Of Averages and Anomalies - Part 1B. How the Surface Temperature records are built
#12 damorbel: relationships between the effect of the Sun and temperature response are a different subject. Hansen and Lebedeff used pairs of stations, i.e. actual observations, to test the strength of spatial correlation and they found from their data that at 1200 km separation the temperature change correlation coefficient dropped below 0.5, so used 1200 km as their cut off for weighting. This doesn't sound unreasonable to me. There is a real temperature field, and for a large enough number of point observations you get a statistically good idea of spatial & temporal variability. I trust Hansen, Lebedeff and their reviewers did a reasonable job with the statistics until someone shows me otherwise. Can you demonstrate using the data that this isn't true, or pick out a mistake that invalidates the results of HL87? -
Camburn at 00:32 AM on 31 May 2011The Critical Decade - Part 1: The Science
KL: The rate of rise of sea levels has slowed. This is not in question. The current rate is under the 1915-1950 rate, and under the 1970-2000 rate. That is not questioned as it is very well documented. The question is, will the rate continue at its present level or accelerate. I have no clue.Response:[DB] "The rate of rise of sea levels has slowed. This is not in question."
Incorrect. This is well-documented and not in scientific question, as you say. See my response to okatiniko at 58 above (specifically the Church & White 2011 reference).
I suggest learning more about the science before making such unreferenced and authoritative statements.
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Camburn at 00:28 AM on 31 May 2011The Critical Decade - Part 1: The Science
DB@64: When we are talking Greenland, I am thinking that the temp metrics affecting Greenland would be the source. We all know that temps in and around Greenland in the 1940's are very similiar to temps today. It may be hot or cold in Australia, that will not affect the Greenland area. The temps in and around the Greenland area will affect Greenland.Response:[DB] My point was that you are cherry-picking when comparing the current global warming period (largely caused by man) to the earlier warming period in which Greenland warmed disproportionatley more than elsewhere.
Glaciologists are well aware that current ice and ice discharge conditions experienced in Greenland have no contemporary equivalent in the past several thousand years. Consider Mittivakkat Glacier in Southern Greenland:
Note the clear progression of ice termination lines, showing the recessionary behaviour of the glacier over the past hundred years.
The consensus of indicators and information available show that, for Greenland, the current warming period is longer and of greater intensity than that of the mid-20th Century, and that warming still in Greenland's pipeline (relative to that already experienced globally) will bring it to, or exceed, the levels of the HCO.
And that is without any compounding warming effects from the ongoing albedo flip underway in the high Arctic.
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damorbel at 23:57 PM on 30 May 2011Of Averages and Anomalies - Part 1B. How the Surface Temperature records are built
Re #12 for autocorrelation read cross-correlation -
DSL at 23:54 PM on 30 May 2011Climate Change Denial book now available!
Tallbloke: "a lot of valid scientific evidence has been either ignored, downplayed, or dismissed on inadequate or incorrect grounds by the IPCC's scientists and policy makers." For example? (on the appropriate thread - and I must say, you haven't done well so far here or at SoD. You suggested SoD work on Miskolczi. SoD did.) Given the sheer amount of idiocy spewed forth in claims that "it's not happening," "it's not us," or "it's not bad," and given the fact that very powerful/wealthy individuals have given out a great deal of money to "inspire" people to argue those three ideas, you--being the true skeptic you claim to be--should be appalled not at the possibility, no matter how small, that the scientific community has "overlooked" or "dismissed" too quickly a few articles or that Gavin or writers at SkS have examined the motivations of others; you should be appalled at the unscientific garbage being cheerfully posted at sites like WUWT (and the intensely uncritical cheerleader reactions in the comments streams) and repeated by lawmakers. If you're concerned enough about the public "debate," why not help clean up the unscientific madness first--as SkS is trying to do--in order to get the public to where actual scientific debate is occurring (clouds, methane, extreme weather)? Where. has. the. scientific. method. not. been. adhered. to? -
damorbel at 23:53 PM on 30 May 2011Of Averages and Anomalies - Part 1B. How the Surface Temperature records are built
Re #11 MarkR et al You cannot learn anything from correlation processes unless you have a clear idea what you are looking for. Autocorrelation is frequently used for detecting (crudely) delay in a signal path; changing the delay enables the full impulse response of the signal path to be determined. Such a process could be used to measure how the temperatures on a planet such as Earth respond to variations tin the Sun's output. It is known that the sun's output varies in a cyclical way (basically 11 years but really rather more complex). It would be of interest to try to extract the dependence of any given temperature, global or local, by finding the correlation (at various delays) between the Sun's output and any temperature. As yet I have seen no attempt to do this. What Hansen is doing is looking to see if he can reconstruct temperature records where there aren't any which is creative, not scientific. There will always be a limited correlation between temperatures, the effects of variations in the Sun's output will see to that; trying to use this to support the argument that man, through generating in a surplus of CO2, is changing the climate of the Earth seems to me to be tenous in the extreme. -
Ken Lambert at 23:37 PM on 30 May 2011The Critical Decade - Part 1: The Science
Riccardo #50 DB and others Whether you want to quibble about the Jason 1 & 2 SLR records being 1.6, 1.8, 2.0 or 2.3mm/year for the last 8-9 years, it is surely significantly less than the 3.1mm year average for the UCAR 1993-2011 chart, and the oft quoted figure from the likes of the Australian Climate Commission. This cannot mean anything else than SLR slowing or decelerating - not accelerating. While ice melt is hard to measure, Dr Trenberth suggests in his Aug09 paper that approx 1mm/year is from glaciers and another 1mm/year from major ice sheets. A total of approx 2mm/year from ice melt. This 2mm/year for ice melt estimate leaves nothing much when subtracted from the 1.6-2.3mm/year for the component of steric rise - ie. the thermal expansion of all that heat sequestered in the oceans from global warming imbalance. Hence steric rise estimates like 0.5+/-0.5mm/year and 0.8+/-0.8mm/year pop up in the literature. If I expresed my height as 1.8m +/-1.8m you would not know if I were a giant or a grease spot. This is the state of play in SLR measurement. If the steric rise has almost stopped, then warming imbalance gap is rapidly closing. This is further confirmed by the energy balance budget. If the SLR components are mostly ice melt, the energy needed to melt ice is very small compared with thermally expanding seawater, and the warming imbalance is small for the budget to close. okatiniko is trying to understand DB's 'correction' point for SLR at #58. Please explain to us all DB?? -
les at 23:14 PM on 30 May 2011Climate Change Denial book now available!
#62 "These are scientific issues, not ones of "pre-defined policy positions". "I want to see the scientific method adhered to, and proper standards and procedures put in place and adhered to for data gathering and the validation and assessment of the outputs of scientific work done by climate scientists." See now, this is what makes me wonder. The practice of climatology and related disciplines has, as far as anyone can tell, been normal, high standard, above board, best practice adhering, science; working it's way thorough available data and models, with their limitations and insights; and proposing new studies. No evidence to the contrary, no evidence of systemic bad practice or distortion. There are, clearly, high quality standards and procedures in place. There really is no good reason why anyone outside the disciplines would want to go round re-analysing every little detail except for for political reasons. That really isn't believable. Fact is there is a conflict for reasons outside the science. That is why somewhere like SkS reviews the science for public consumption. That is why talshop tries to show "it's the sun" - even though that website isn't part of a solar-research unit or such like. -
MarkR at 23:09 PM on 30 May 2011Of Averages and Anomalies - Part 1B. How the Surface Temperature records are built
#5 damorbel; "It is all too easy to 'assume' correlations instead of establishing them; the latter is of course the scientific thing to do." Exactly, that's why they were determined from observations. And why shouldn't there be any hope of correlation if elevation is involved? Higher elevations would expect to be cooler than lower ones, but it's believable that their temperature changes might correlate: they might both warm and cool at the same time which is what is being calculated. Here are some New Zealand stations, with Kelburn being near to the airport, but at a higher elevation. A quick eyeball Mk.I suggests very strong correlation, despite the altitude difference. So it seems that it isn't impossible. -
skywatcher at 23:02 PM on 30 May 2011Climate Change Denial book now available!
#62 You're still not putting up the 'important science that has been downplayed'. Remember that this important science has to have not already been refuted by rational argument in the peer-reviewed litereature. There is plenty to challenge climate scientists and plenty of room for scientific argument, but it does not matter from a policy perspective whether warming will be 2C / CO2 doubling, or 4.5C / CO2 doubling, or if sea level will be 1m higher by 2100, or 4m higher by 2100. It matters from the perspective of determining how much action we take and how quickly, but the answer does not change the fact that we must take action as soon as possible. Uncertainties about climate change do not, from a scientific perspective, include a range of climate change where there will not be serious consequences for modern human society from coastal swamping, extreme weather and poor food security. -
dhogaza at 23:00 PM on 30 May 2011The Critical Decade - Part 1: The Science
okatiniko: "I understand it is a real effect producing a real negative component, so why correct it ?" Because they're trying to measure sea level rise, not the rate at which the land is rising in such regions. -
Kevin C at 22:47 PM on 30 May 2011Are you a genuine skeptic or a climate denier?
Eric #12: Did you look? All the data is on Prall's website, which is in turn referenced in the supplemental material of the Anderegg 2010 paper. The supplemental material is referenced (and hyperlinked in the PDF) version from the article text (at least twice that I could see). He provides all the data you need to repeat the calculations with your own criteria of number of papers or number of cites. -
dorlomin at 22:37 PM on 30 May 2011Are you a genuine skeptic or a climate denier?
What about the luke warmers, those who believe we are warming but it does not require drastic action? -
Eric (skeptic) at 22:29 PM on 30 May 2011Are you a genuine skeptic or a climate denier?
Dikran and John, there are a few problems with Anderegg et al such as: "To examine only researchers with demonstrated climate expertise, we imposed a 20 climate-publications minimum to be considered a climate researcher, bringing the list to 908 researchers" and "We conducted the above analyses with a climate researcher cutoff of a minimum of 10 and 40 publications, which yielded very little change in the qualitative or strong statistically significant differences between CE and UE groups." But they didn't publish those numbers. I am interested in the CE/UE breakdown of climate scientists who only published a few papers, but those statistics were not released in Anderegg.Moderator Response: [Dikran Marsupial] The definition of "climate expert" is still not "self-selected" as a perfectly reasonable objective criterion is given. Whether or not the statistics from a test of the robustness of the findings to the threshold used are published makes no difference to that fact.
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