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muoncounter at 00:54 AM on 23 August 2010What caused early 20th Century warming?
#30: "what TSI produced an equilibrium temperature of the Earth system in pre-industrial times with no other external forcings" I'm not sure what you mean. Why require 'no other externals?' Although volcanic cooling, as you suggest, is short-lived (even Pinatubo was only a 2-3 year event). And I am not aware of the significance of an 'equilibrium pre-industrial temperature'. The TSI data I've looked at (for example) show a short-term oscillation, which matches sunspot numbers reasonably well, modulated by long term signals (also present in sunspot numbers). For example, there were deep sunspot lows in the early 19th and again in the early 20th centuries. To the extent that surface temps follow these long term signal, do we not say 'its the sun?' However, when surface temps diverge from the solar signal, should we not look for the cause? What cause are you proposing? -
Ned at 00:42 AM on 23 August 2010Weather vs Climate: Watch the waves, miss the turning of the tides
Are those highs and lows for stations worldwide? In the US only? The graphic has a map of the US as its background ... Might be helpful to include a link to the source of the graphic.Response: It is US only. The paper it comes from is Meehle 2009. It's referenced in the intermediate rebuttal - we're still mulling over how much detail to include in the basic version - whether to include references or just link to the intermediate version for all the nitty gritty details. -
eric144 at 00:31 AM on 23 August 2010Is the sun causing global warming?
The Ville You seem to be determined to find some excuse for disbarring Kirby's science. None of them valid. -
theendisfar at 00:23 AM on 23 August 2010There's no empirical evidence
KR, So it's not so much gibberish in that it can't be clarified, it was gibberish because of a lack of understanding and trust of the source. This is relevant because if what I have stated is accurate, cannot be falsified, then one of the understandings must be wrong. Barring someone able to falsify the understanding I have, I hold it to be accurate. And of course it has zero effect at the top of the atmosphere, where radiation is the only energy exchange with space. This is good, we agree. Convection stops at the Tropopause. Where the Earth was able to cool via Conduction, Convection, and Radiation starting at the surface, it lost Conduction with only a small amount of altitude, and then it loses Convection at the Tropopause. A transfer of energy means that energy has traveled over distance. To say that conduction plays no or little part in cooling the Earth's surface because Radiation is the only ultimate escape is nonsense. To say the same of Convection is equally nonsense. I took a look at Trenberth et al, is this what you're getting your info from? Imagine for a moment I had "provided a review of past estimates", and "performed a number of radiative computations", and "values constrained by", and ""but adjusted to an estimated imbalance", and "Revised estimates", and "radiation is adjusted", and "by making modest changes" in the short understanding I posted above. It opens far more questions than it would have answered. Again, just because convection only moves energy to the Tropopause does not mean it is not the primary transport of energy from the surface to it. Just because Conduction only moves energy from the surface to the immediate atmosphere above it, does not mean it is not the primary transport of energy to it. Any issues with #129? Make sense? -
shdwsnlite at 00:01 AM on 23 August 2010University of Western Australia Open Day 2010
I wish that some Universities in the US would create a similar program. -
Esop at 23:57 PM on 22 August 2010The main culprit in mid-century cooling
#4: very good point regarding China. From the late 90's to around 2005, the industrialized southern part of China (Shenzhen, etc) was covered in a dense haze, caused by emissions. Airborne dust and particles made it very uncomfortable to be outside. This has cleared up a lot over the past few years since around 2006. It is very possible that the Asian "brown cloud" helped mask the temperature increase on the early 00's, then, as it improved towards the end of the decade, temps started climbing faster again. -
Alexandre at 23:05 PM on 22 August 2010Weather vs Climate: Watch the waves, miss the turning of the tides
Now that's a great analogy. I'll definetly use this one. -
kdkd at 22:59 PM on 22 August 2010What caused early 20th Century warming?
Ken #30 Alternatively you can estimate the effects of different forcing components by looking at linear models of the forcing components at different points in time. (Un)surprisingly we find that CO2 has been the main forcing component for the last 40-odd years, while the solar component was dominant previously. We also know that major volcanic forcings only last very short periods of time. So all this stuff can be estimated without estimating this 'equilibrium TSI'. -
Ken Lambert at 22:12 PM on 22 August 2010What caused early 20th Century warming?
muoncounter #28 Tell us what TSI produced an equilibrium temperature of the Earth system in pre-industrial times with no other external forcings (eg; volcanic cooling). With a fix on that 'equilibrium TSI' you can then estimate what excess Solar forcing has occurred over the 20th century and the total energy added to the system. -
Ned at 22:08 PM on 22 August 2010What were climate scientists predicting in the 1970s?
A tiny mathematical correction; Marcus's 100 ppm rise above a preindustrial level of 280 ppm would be a 36% increase, not 27%. And since current levels are actually around 392 ppm, it's really a 40% increase in CO2 (and rising every year). -
Ned at 22:05 PM on 22 August 2010The Past and Future of the Greenland Ice Sheet
Peter Hogarth wrote: I dont think Ned has suggested that current ice loss is greater than anything seen in the early holocene... and Berényi Péter replied: According to Figure 1 in the article current rate of ice loss is 26000 km3/century. That's three times faster than average rate of loss in any millennium in the last ten thousand years. So yes, he did suggest such a thing. Figure 1 shows the change in mass balance of the Greenland ice sheet over the past decade, as measured by GRACE. If Berényi Péter wants to claim that this rate of change is greater than the maximum decadal-scale rate of change during the early Holocene, that's his claim, not mine. I don't think that citing millennial-scale averages would be a good way to justify that claim. I spent a fair bit of time working on the phrasing of that post, to ensure that I didn't make any claims for which there was not clear evidence. Probably the most important point from that post is that the Greenland ice sheet was quite a bit smaller during previous interglacials. Since the projected 21st-century global mean temperature increase of 3C implies an Arctic warming of more than 3C, this is reason for concern. Thus, it becomes urgent to answer the question of how rapidly the Greenland ice sheet will respond to the upcoming temperature increase. As I discuss in the latter part of the post above, Pfeffer 2008 suggests that via realistic ice dynamics Greenland could contribute 16 to 54 cm as its share of a global sea level rise of 0.8 to 2 m by 2100. This also seems to fit well with Vermeer and Rahmstorf 2009. So I don't think there's any realistic way we could produce an Eemian (MIS-5e) ice sheet by 2100. But we could take a substantial step in that direction, and 0.8 to 2 m of SLR will have quite high economic costs in many regions. -
Marcus at 21:14 PM on 22 August 2010What were climate scientists predicting in the 1970s?
GC, also consider this-if a mere 100ppm increase in CO2 emissions has been sufficient to raise global temperatures by +0.6 degrees C, what do you think another 300ppm to 600ppm might do to our climate? So long before we come close to running out of coal & oil, we will have been able to significantly altered our atmosphere & climate-perhaps to levels in which human civilization can no longer survive. Personally, I'd rather stop treating our planet's atmosphere like some giant laboratory-unlike the fossil fuel industry who're quite happy to use it in such a way. -
Marcus at 21:09 PM on 22 August 2010What were climate scientists predicting in the 1970s?
Gallopingcamel #31, that's total *rubbish*. Pre-industrial levels of atmospheric CO2 was 280ppm, it is now above 380ppm. Even simple knowledge of mathematics should be able to tell you that this represents an anthropogenic increase of of 27% above natural levels, not 0.01% as you claim. Of course, RSVP would have us believe, wrongly, that an addition of anthropogenic heat-from industrial activity-that is less than 0.001% of the total heat received from natural sources-is sufficient to warm our planet in a way that a nearly 30% increase in IR-capturing gases can't. So who, again, is guilty of hubris? -
Marcus at 20:49 PM on 22 August 2010What caused early 20th Century warming?
John D #22. Again with that cloud cover diagram. I've already pointed out how dubious that diagram is, given that its so obviously an example of CHERRY PICKING. Specifically, there is no indication if that peak on the LHS of the graph is typical or not. If its atypical, then the so-called decline in cloud cover is non-existent (if you go on cloud cover levels just a couple of years *before* the peak). When you can provide a diagram that covers a longer time-frame, then maybe I'll consider it. Fact is that, based on everything I've read, the strength & frequency of El Ninos & La Ninas is at least partly linked to the levels of atmospheric warming. Now whilst we had a warming trend of +0.06 degrees per decade from 1900-1950-driving by an upward trend in sunspot numbers, we've had a warming trend of +0.12 degrees per decade for 1950-2000 driven by....? Well, not increasing sunspot activity, that's for certain. -
Berényi Péter at 20:28 PM on 22 August 2010The Past and Future of the Greenland Ice Sheet
#65 Peter Hogarth at 16:58 PM on 22 August, 2010 I dont think Ned has suggested that current ice loss is greater than anything seen in the early holocene... According to Figure 1 in the article current rate of ice loss is 26000 km3/century. That's three times faster than average rate of loss in any millennium in the last ten thousand years. So yes, he did suggest such a thing. In the three millennia before the beginning of the Holocene (15-12 ka ago) ice loss was faster, 20000-60000 km3/century (depending on model details), but that must have been caused by sea level rise induced breakup of ice shelves around Greenland, not local temperatures. Currently we do not have any large ice sheets melting far away from Greenland that could cause fast eustatic rise not compensated by local crustal rebound, neither have we extensive thick ice shelves around the island prone to sea level rise induced breakup. Therefore that kind of thing can not possibly occur now. Anyway, the "alarming" melt has started only ten years ago and has accelerated to its present rate in the last couple of years. Anything shorter than three decades is surely weather, not climate. Greenland (as opposed to East Antarctica) is a "wet" icesheet, not a "dry" one. Mass balance depends on precipitation to a high extent. With more open water around in the region increasing trend of snow accumulation of the last several decades should resume sooner or later. As many researchers have commented there is little sign of any known factor which will slow it down in the near future If so, tell them summer temperatures north of 80N are dwindling at an alarming rate during the last two decades. And this freezup in the high Arctic is clearly accelerating.
In the meantime tell the Chinese to stop emitting untold amounts of soot in the atmosphere that's carried off right into the Arctic by prevalent winds. Soot pollution is not a necessary consequence of burning stuff. To make combustion more efficient and filtering smoke properly is not that expensive, the technology is ready, it is already done in any sane country.
Best Hope for Saving Arctic Sea Ice Is Cutting Soot Emissions, Say Researchers
While we are at it. Going for a ban on small diesel engines (a great source of tiny black carbon particles) and installing proper filters on large ones (including ship engines) is also a possible line of action, far more promising than the futile war on CO2.
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scaddenp at 20:04 PM on 22 August 2010Can't We At Least Agree That There Is No Consensus?
poptech -I REPEAT - I do not claim they are related to tobacco industry only that the journal is used for "tobacco science" style tactics. Namely, like the tobacco industry had with "Indoor and Built Environment", you have a tame journal for printing rubbish so you can claim "peer -reviewed articles" to back dubious claims. And look - you are doing it. And of course the knights of tobacco science were our friends in Heartland. If the journal was publishing anything of value to climate science, then other papers would be building on the science published there rather than demolishing it. Any sign of that happening - no. Cites to refute an article and cites in E&E dont count as "influencing science". -
Anne-Marie Blackburn at 19:39 PM on 22 August 2010The main culprit in mid-century cooling
Hi Nigel. Yes, if you look at all the factors affecting climate change, aerosols have had a cooling effect and have therefore masked some of the warming expected from increasing levels of greenhouse gases. Some scientists have even suggested that we could inject huge quantities of sulfate aerosols into the atmosphere to keep global warming under control. Though technological and environmental issues mean that it's unlikely at the moment. -
CBDunkerson at 19:38 PM on 22 August 2010The Past and Future of the Greenland Ice Sheet
Given that increased ocean temperatures are helping to drive calving would it be reasonable to assume that once all the 'coastal' ice has broken away the rate of ice loss on Greenland (and Antarctica) should drop significantly? Or would exposed beach lead to greater melt and runoff? Have the regions of Greenland which are NOT covered by ice been seeing significant mass loss from the nearby portions of the ice sheet in recent years? From what I can tell the various 'mass balance' maps of Greenland the mass loss seems to extend well inland - presumably past any region that seawater temperatures should be impacting. I'm trying to get a handle on whether we'd expect Greenland ice loss to continue accelerating indefinitely or if there will be a slowdown once the coastal ice is gone. -
papertiger at 19:09 PM on 22 August 2010Dust-Up On Mars: Should Martians Be Sceptical of Global Warming?
At least you are aware that there was a MWP. That puts you a step in front of John Cross. http://www.skepticalscience.com/medieval-warm-period.htm -
Peter Hogarth at 16:58 PM on 22 August 2010The Past and Future of the Greenland Ice Sheet
Berényi Péter at 13:23 PM on 22 August, 2010 Thanks for fixing the link. I had not seen the Simpson paper, but at first glance fair to say your adapted chart is a simplification from their models? I'll digest the paper before drawing further conclusions. I dont think Ned has suggested that current ice loss is greater than anything seen in the early holocene... I think the fundamental argument is that current loss is not a transient event but a recently emerged and ongoing significant loss trend. As many researchers have commented there is little sign of any known factor which will slow it down in the near future (though I recall future shutting down of AMOC has been modelled). -
Doug Bostrom at 15:33 PM on 22 August 2010The Past and Future of the Greenland Ice Sheet
BP, I'm trying to grasp how the volume of water that was on land and then moved to the ocean could cause a change in air pressure. Was this entirely due to rebound? (for that matter, I'll have to look up if rebound is actually conservative; that is to say, does what squishes down cause something to bulge up somewhere else? I find I don't really know or if I did I've forgotten...) -
gallopingcamel at 15:19 PM on 22 August 2010What were climate scientists predicting in the 1970s?
Marcus (#26), The source of the carbon that humanity is adding to the atmosphere is fossil fuels. You talk about the last three centuries so use a bit of imagination and ask yourself how much will be left of the fossil fuel reserves in 2300 if we continue on our present course of industrialization and population growth. Long before the CO2 gets to 1,000 ppm fossil fuels will be so scarce (hence expensive) that they will be limited to special applications. We will be forced to depend on nuclear power and in particular the Thorium cycle. If we are clever enough we may even develop fusion power plants. The CO2 problem will have solved itself. Erratum from an earlier post. I said that mankind had added 0.1% to the atmospheric CO2 concentration. Mea culpa, I lost a decimal place and the correct figure is ~0.01%. -
solarsparky at 15:04 PM on 22 August 2010Dust-Up On Mars: Should Martians Be Sceptical of Global Warming?
Whenever I get told this one, I always ask what the temperature was on Mars during the Medieval Warming Period? Haven't had an answer yet -
There's no empirical evidence
theendisfar - as in our previous conversation, I refer you to Trenberth et al 2009. The measured energy leaving the surface of the Earth run to 396 W/m^2 IR [pyrometers and FTIR spectrometers], 78 W/m^2 latent heat (evaporation) [from global precipitation and energy required to evaporate that much water], and ~24 W/m^2 convection [various estimates, but primarily what's left over]. Measured, repeatable (and frequently repeated) numbers. Unless you have measurements to the contrary, convection is 1/3 the energy of latent heat, and 1/16th the energy of IR, not the dominant effect you claim. And of course it has zero effect at the top of the atmosphere, where radiation is the only energy exchange with space. Next objection to the greenhouse effect? -
Berényi Péter at 13:23 PM on 22 August 2010The Past and Future of the Greenland Ice Sheet
Unfortunately the Simpson 2009 link above is not correct. Here is a better one. Quaternary Science Reviews 28 (2009) 1631-1657 doi:10.1016/j.quascirev.2009.03.004 Calibrating a glaciological model of the Greenland ice sheet from the Last Glacial Maximum to present-day using field observations of relative sea level and ice extent Matthew J.R. Simpson, Glenn A. Milne, Philippe Huybrechts, Antony J. Long -
muoncounter at 13:18 PM on 22 August 2010What caused early 20th Century warming?
#27: "in the early century, most of those years had low sunspot activity " 'Relatively' low sunspot numbers, yes; but the peaks are increasing through the first half of the 1900s. Anne-Marie's logic is sound. Long term cycles in solar output are apparent; Bonev etal 2004 reached this conclusion: "the present epoch is at the onset of an upcoming local minimum in the long-term solar variability. There are some clues that the next minimum will be less deep than the Maunder minimum" (emphasis added)
That sounds like the next few cycles are predicted to continue the downward trend that began after the 1960 peak; so why are we still warming?
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Berényi Péter at 13:00 PM on 22 August 2010The Past and Future of the Greenland Ice Sheet
#61 Peter Hogarth at 09:46 AM on 22 August, 2010 Your calculations are therefore dubious Not very much. According to Simpson 2009 between 10000 BP and 3000 BP the average volume change of the Greenland ice sheet is about -5700 km3/century. It translates to an eustatic sea level rise rate of 15 mm/century, still not alarming. The fastest loss rate they show is about -8000 km3/century between 5000 BP and 4000 BP. For the sea level it is still not more than 22 mm/century.
As present ice loss rate is supposed to be much faster than anything seen during the early holocene when arctic temperatures were higher than now, it is either measurement error or a transient which can not last for long (a "weather event").
Greenland is very interesting, but rest assured, not dangerous for coastal cities.
BTW, I have just found something curious. It is not immediately related to Greenland, but to the wider context of glacial - interglacial transition.
As the great continental ice sheets of America and Europe melted, sea level rose by about 120 m. This added water displaced an equal volume of atmosphere, which increased air pressure over land everywhere on the globe by about 1%, except at former ice margins where uplift of land was larger than that of the atmosphere due to postglacial rebound.
The pressure increase translates to a 0.5°C global land surface warming via lapse rate. This additional heating have not occurred over the oceans, so it must have had a pretty large effect on global circulation patterns.
Anyway, it would deserve a closer look and somewhat more accurate calculations.
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Geo Guy at 11:57 AM on 22 August 2010What caused early 20th Century warming?
Unfortunately your assertion that solar activity since the 1950's has been stable is wrong according to historical records of sunspot activity. Have a look at the following Australian government link where graphs of historical solar cycles are available. More sunspots equates to more radiated heat. http://www.ips.gov.au/Educational/2/3/1 (my apologies but I use Firefox and post links as per the hints provided) From the aforementioned link, you should note that sunspot activity in the early 60's was at an all time high post 1750. Sun spot activity during the 80's and 90's were the second and third highest for that period. As for the warming in the early century, most of those years had low sunspot activity hence I can't see how you can arrive at your conclusion that the warming is attributed to increased solar activity. -
Doug Bostrom at 10:30 AM on 22 August 2010The Oregon Petition: How Many Scientists Does It Take To Change A Consensus?
Forget about mirrors, consistency, glass houses, your hurt feelings etc. theendisfar. The point is, you're arguing from the perspective that scientists are not trustworthy and that makes a discussion with you entirely pointless. Some of the self-described skeptics appearing here don't seem to believe they're victims of some fantastical plot run by a myriad of scientists and that means it's technically possible to have a productive discussion. Useful conversation with those expediently conjuring up imaginary scientific misconduct, conspiracies etc. is impossible because such artifices are a form of evasion, a way of saying "I doubt it" without having to provide any argument. If you've ever tried to talk down the anxieties of a person who is technically paranoid you'll understand what I mean. My observation is that the response of such a person when boxed in by logic is to imagine a new world with features excusing them from following logic. Mind, I'm not saying you're delusional, I have no way of knowing that. What I will say is that making broad, negative generalizations about the character and methods of a myriad of scientists does sound rather like inventing a new world with conveniently inexplicable features. -
Tom Dayton at 10:15 AM on 22 August 2010The Oregon Petition: How Many Scientists Does It Take To Change A Consensus?
theendisfar, in addition to the excellent replies you've already gotten in response to your invocation of Popper and your contention that consensus has no role in science, you should read the Skeptical Science response to the Argument There is no consensus". In addition to that post, I suggest you watch Naomi Oreskes's "Consensus in Science: How Do We Know We're Not Wrong?," which I link in my comment there. Also read another of my comments there, regarding the role of scientific consensus. Then my followup two comments here, and about math here, and about Kuhn's description of science here. Also relevant are comments about what science really is. You might start with mine.Moderator Response: Further detailed discussion of the nature and role of consensus in science is better done on the more general thread "There is no consensus," because this thread we are reading now is devoted more narrowly to the Oregon Petition. -
theendisfar at 10:08 AM on 22 August 2010There's no empirical evidence
KR, In particular, "Trapped radiation will only serve to slow the radiative cooling exhibited by black body radiation" is completely insensible - random words that don't mean anything to me. Thank you. I believe I can make it clear. If an object is radiating at 390 Watts/m^2 (m^2 is meters squared) and a GHG absorbs some of it and sends back 2 Watts, then the rate of cooling via Radiation has dropped to 388 Watts/m^2. Since a Watt is a joule/second, then the most obvious choice of words to me was to say that it 'slowed'. Keeping in mind that radiation travels at the speed of light, any IR trapped by CO2 is in effect trapped at the surface since it's frequency at the surface is every 1/150,000,000 seconds if trapped at 1 meter or 1/15,000 seconds if trapped at 10,000 meters. Temperature changes over such short time periods and so little energy can, for practical purposes, be seen as not changing. To describe the 'trapped' energy when it is away from the surface requires one to predict it's location within the atmosphere which is highly variable and since everyone is so concerned with it's contribution to surface temps, that is the obvious choice again. So, if you consider the 'trapped' energy as stuck at the surface, or better yet, when you are measuring it it is at the surface, then in practical terms you have reduced the radiation rate by 2 Watts. Now consider that a cubic meter of water at 15 C (average Sea Surface Temp) contains about 1.2 Billion joules, a reduction in cooling of 2 Watts is a 12 hour reduction of 86,400 Watts. Sound like a lot? Consider it takes a 4.1 Million joule increase to raise that 1 cubic meter of water 1 C. However, the radiative resistance does not impede Convection or Evaporation (where available), in fact, since a slight increase in Temperature will be observed at the surface, the Convection rate will increase accordingly. Better? -
Berényi Péter at 10:03 AM on 22 August 2010There's no empirical evidence
#124 KR at 07:52 AM on 22 August, 2010 Delamere et al 2000 is an interesting paper. But they fail to show actual data for TOA emissions. Of course they don't do that. It is about modeling, not measurement. But they do provide some hints regarding why these quantities are not measured properly yet. -
Doug Bostrom at 10:03 AM on 22 August 2010Can't We At Least Agree That There Is No Consensus?
"Popularity?" What's in a word? Citations are among other things a measure of the utility of a paper's content. In the scientific world a paper is useful when it helps to provide a framework for further exploration. So not popularity in the sense of "People" magazine. Meanwhile, all citations are not equal. A citation to an article from a paper authored by a pundit at a thinktank is not a very good indicator of that article's scientific merit. Poptech you seem very invested in E&E, presumably because it's a journal offering easy acceptance of articles that can't find a publisher elsewhere and thus many articles important to "skeptics" appear in E&E. Earlier I wondered if you could inform us about what fraction of the world's libraries subscribe to E&E. You'd mentioned a figure of something less than 500 libraries counting E&E among the journals on their shelves, that apparently being a usefully large number to convey the impression the journal has heft. Did you ever tease out that fraction from your information sources? -
theendisfar at 09:57 AM on 22 August 2010The Oregon Petition: How Many Scientists Does It Take To Change A Consensus?
Doug, A sudden epiphany, theendisfar? In a manner of speaking. Having commented on deception my argument was self defeating in a couple of ways. First, I was claiming AGW has done a poor job of proving anything, essentially speculating, and then I was doing the same thing with the regards to the folks I was detracting. Second, it has proven to be a terrible distraction, this post is further evidence of that. A different paradigm is exposed when you look in the mirror and apply the standards you hold others up to. I made a mistake and the quicker I own up to it the better. Too much torque, your credibility is snapped. Fair enough, do not take any of my statements at face value. What, you didn't before? :) I expect a fair amount of knocking, I made some dumb comments that I thought were harmless enough without carefully predicting the outcome. What I said is on par with many inflammatory remarks made about Skeptics, here and elsewhere. Not excusing any of it, just reminding those that live in glass houses. -
Berényi Péter at 09:56 AM on 22 August 2010There's no empirical evidence
#123 KR at 07:49 AM on 22 August, 2010 do you think that in other wavelengths the top of atmosphere (TOA) emissivity has increased? Yes. Note that the measured TOA emissivity has decreased at all observed wavelengths in that graph. In the graph, yes. Not in reality. As I have already told you, the offset in the graph is arbitrary. TOA radiative imbalance, as measured by satellites, have some 6 W/m2 uncertainty. Can you produce evidence to that effect? If not, I can't take your comment seriously. You can't produce evidence to the contrary either. The 0.9 W/m2 radiative imbalance at TOA is only assumed, never measured. In order to be taken seriously you have to be able to tell assumptions and facts apart in the first place. -
Peter Hogarth at 09:46 AM on 22 August 2010The Past and Future of the Greenland Ice Sheet
Berényi Péter at 06:03 AM on 22 August, 2010 Yes, my first comment was released in haste and was incorrect, apologies (I was looking at the bedrock uplift data for Agassiz and Renland, which amount to over 100m and around 300m respectively in the same period). I think we have to read the whole paper rather than making fast judgements. As you know, the percentage of d18O in the gas trapped in the ice core is used as a temperature proxy. It must be corrected for altitude (and latitude) hence an estimate of elevation at deposition time is required. Assuming similar d18O histories and known elevation history at one site allows past elevation at nearby sites to be more accurately constrained. Glacial Isostatic Adjustment has also to be factored in. Your calculations are therefore dubious (but at least not upside down...)
The difference between elevation histories at core sites in the centre of the Greenland ice sheet and the margins gives evidence that the loss at the margins of the ice sheet is very sensitive to temperature changes and these margins have responded rapidly in the past. This is analogous to what we are currently measuring and seeing. The recent reversal in the long term downwards Arctic temperature trend (Kaufman 2009 etc), appears to require more than is possible from natural variations or forcings, and Vinther argues in his conclusion that relatively small temperature changes could lead to greater mass losses than previously thought.
Vinther 2009 states: “Greenland ice sheet (GIS) is an important concern, especially in the light of new evidence of rapidly changing flow and melt conditions at the GIS margins”.
I agree. These recent mass losses are not “weather noise”.
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nigelj at 09:35 AM on 22 August 2010The main culprit in mid-century cooling
Could aerosols from industrialisation in China and coal fired stations elsewhere be damping down the warming trend over the last decade? -
Berényi Péter at 09:30 AM on 22 August 2010The Past and Future of the Greenland Ice Sheet
#60 Peter Hogarth at 07:18 AM on 22 August, 2010 That is, the 10,000 year elevation change shown here is upwards (crustal uplift), rather than downwards (ice loss), as you have incorrectly interpreted it to be. No, it is not. You are surely not trying to tell us total gas content of an ice core decreases with increasing atmospheric pressure at depositional elevation.
and I am not “you guys”
Sorry for that, sir. It will never happen again.
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johnd at 09:06 AM on 22 August 2010The main culprit in mid-century cooling
Focusing on the cooling period as indicated above, 1945 to 1975, that period began with 2 declared El-Nino years that were much stronger than normal. Including those 2 years, a total of 10 years within the nominated period were declared El-Nino years. There was also 10 La-Nina years within the same period with the 3 final years being successive declared La-Nina years. HOWEVER, virtually the whole period, in fact the exact period was dominated with the SOI predominately and quite strongly in the positive (wetter) phase, and the IPO entirely and also very strongly in the corresponding negative (wetter)phase. The IOD was in the postive phase(drier) 3 times whilst in the negative (wetter) phase 4 times. The negative phase of the IOD is a pattern with cool SST in the Indian Ocean west of Australia, and warm SST in the Timor Sea to the north. For Australia overall, this cooling period was also a period of generally higher rainfall, so irrespective of what else may have been happening in the atmosphere, the amount and distribution of cloud cover would have had a determining influence on both how much the SST's warmed and cooled, and where, as well as where the moisture that formed into those clouds was carried to and deposited. Clouds also affect temperatures, causing lower temperatures during the day and warmer at night, so more clouds are not only indicated by the generally higher rainfall, but consistent with how temperatures varied also. -
MattJ at 09:02 AM on 22 August 2010Is global warming still happening?
Excellent rebuttal! I have only one suggestion to make, it is already so near perfect;) In place of the fancy sounding word, 'indicator', use the more normal sounding word, 'sign', which really will be readily understood here as meaning the same thing. -
David Horton at 08:15 AM on 22 August 2010The main culprit in mid-century cooling
Yes, good post. Something I am mildly curious about is why the post 1975 heating doesn't converge on the trend line up to 1940, but runs parallel and offset down. Is it because there is still substantial (even if lower) aerosol presence? -
dhogaza at 08:15 AM on 22 August 2010The Strange Case of Albert Gore, Inconvenient Truths and a Man in a Powdered Wig
TOP:The Scopes trial got evolution pretty close to being the codified into law in many places. At least you can't teach or even discuss opposing viewpoints.
Of course you can. You can't teach creationism in *science* class, because it's not science. This would be true even if evolution were false. But you can certainly teach creationism in the context of *religious studies*. In case you haven't noticed, the Torah is a religious work, not a scientific work. -
Doug Bostrom at 08:07 AM on 22 August 2010The Oregon Petition: How Many Scientists Does It Take To Change A Consensus?
A sudden epiphany, theendisfar? Too much torque, your credibility is snapped. -
Doug Bostrom at 07:57 AM on 22 August 2010There's no empirical evidence
Look, folks the precedent on this site is that assuming you can wrestle him/her to the ground w/regard to basic physics, theendisfar will then apply this dog-eared joker from the skeptic deck: "Without going into motivation, Yes, I think many climate scientists are purposely misrepresenting conjecture as empirical and repeatable evidence quite frequently using subjective terms to provide wiggle room and plugging conjecture into GCM's, passing the predictions off as reliable." Once you actually get back to empirical evidence as opposed to heading back into the 19th century to rehash classic thermodynamics and the like, whatever data you may end up discussing will be dismissed as the result of a vast conspiracy or whatever it would take to support theendisfar's hypothesis of rampant corruption in the scientific community. So I really wouldn't bother w/rejoinders, attempts at correction or the like. I'll hazard a guess that theendisfar is here for kicks, nothing more. -
There's no empirical evidence
Berényi - Delamere et al 2000 is an interesting paper. But they fail to show actual data for TOA emissions. -
theendisfar at 07:50 AM on 22 August 2010The Oregon Petition: How Many Scientists Does It Take To Change A Consensus?
Doug, I can understand your skepticism and can only say that time is the best measure and that #55 is sincere. Trust me, if you look at the Empirical Evidence thread you can see how stimulating the AGW community is being. Mind numbingly For what's it worth I repeat Making claims, to date, that are unfounded and accusations without the accused present is not worthy of discussion and upon reflection is amateur and low respectfully and arguably inclusive. I was raised and educated to be above this behavior and will seek to reinforce this claim. Take it or leave it, so long as I an free to comment here I will do so in the manner described above. -
There's no empirical evidence
Berényi - do you think that in other wavelengths the top of atmosphere (TOA) emissivity has increased? Note that the measured TOA emissivity has decreased at all observed wavelengths in that graph. Can you produce evidence to that effect? If not, I can't take your comment seriously. -
There's no empirical evidence
There's a phrase by Wolfgang Pauli that I find appropriate, "That's not right - that's not even wrong". What you've posted is nonsense. In particular, "Trapped radiation will only serve to slow the radiative cooling exhibited by black body radiation" is completely insensible - random words that don't mean anything to me. How could energy accumulation slow radiative cooling? That completely reverses cause and effect - slowing of radiative cooling traps energy, not the other way around. You're just not making sense. When you do, great. Until then, well, babble just isn't worth my time. In the meantime, I would suggest reading up on the Greenhouse Effect, and how it actually works. -
theendisfar at 07:40 AM on 22 August 2010There's no empirical evidence
Tom et al, To those that think 107 - 110 are gibberish, can at least one of you provide an example? Pick the first obvious one, the understanding is progressive so an early error will likely falsify the rest of it. Does Temperature as 'Energy Pressure' not make sense? Makes sense if you take into account that a joule = a newton with regards to Energy. They are equivalent. Energy/Volume = Pressure. Anyone? -
tobyjoyce at 07:37 AM on 22 August 2010The Oregon Petition: How Many Scientists Does It Take To Change A Consensus?
Re: Karl Popper Popper was a wonderful man, a great philosopher, and a brilliant writer. But there is much more to the philosophy of science than Popper and he has his detractors. His "falsificiationism" is probably a bit old hat today, but is a wonderfully useful rule, like Ockham's Razor or Hume's Fork. His best book is actually a work of political philsophy The Open Society and its Enemies. A contending branch of the philosopy is Thomas Kuhn's Structure of Scientific Revolutions, which is a more sociological view. Kuhn points out for example that for centuries Newton's Laws did not explain the orbit of Mercury. But scientists did not immediately abandon Newton's Laws - they were much too useful. So Kuhn believed that science works in "paradigms" (a word he invented, and later regretted!). Basically "normal science" continues with its paradigms until evidence begins to contradict a formerly accepted theory. Scientists will try to "save the theory" by modification, but eventually a new paradigm in the case of "revolutionary science" is accepted. The eventual acceptance of continental drift, along with plate tectonics, is a good example of this. There are other manifold and variegated views of science, like the Duhem-Quine thesis Duhem-Quine. Climate science actually depends on fairly straightforward paradigms of radiation physics and atmospheric physics. To falsify it, these would need to be undermined to a significant degree. But anyone is welcome to try.
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