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carrot eater at 11:47 AM on 29 June 2010What causes the tropospheric hot spot?
Andrew, Your instincts are correct. If the surface is warming, then the tropical troposphere should warm faster than the surface, no matter what is causing the warming. So there is no fingerprint there. But above that, if the stratosphere is at the same time cooling, that is indeed a fingerprint of enhanced greenhouse effect. Caveat being that ozone loss also causes strat cooling, but that effect is more limited to a certain altitude band. -
Rob Honeycutt at 08:52 AM on 29 June 2010What causes the tropospheric hot spot?
Ah, yes Andrew. I made the same mistake myself. Did they point to where in the IPCC report that it says that? I would be curious. -
David Grocott at 08:47 AM on 29 June 2010What causes the tropospheric hot spot?
Peter, Really interesting post, thanks. Particularly appreciate the (newer) Santer graph. Re: Paltridge, here’s a couple of quotes from the study itself:Radiosonde humidity measurements are notoriously unreliable and are usually dismissed out-of-hand as being unsuitable for detecting trends of water vapor in the upper troposphere.
It is of course possible that the observed humidity trends from the NCEP data are simply the result of problems with the instrumentation and operation of the global radiosonde network from which the data are derived. The potential for such problems needs to be examined in detail.
Despite these caveats, Paltridge does, quite rightly I feel, argue that “the NCEP data for the middle and upper troposphere should not be “written off”…Since balloon data is the only alternative source of information [as opposed to that taken from satellite measurements] on the past behavior of the middle and upper tropospheric humidity and since that behavior is the dominant control on water vapor feedback, it is important that as much information as possible be retrieved from within the “noise” of the potential errors.” However, on the recommendation of the Elliott and Gaffen study (1991), Paltridge’s study only covers the reanalysis data from 1973 to 2007 and limits its examination to particular latitudes between 50° S and 50° N, and atmospheric pressures up to up to 500 hPa everywhere, together with the summer season data from 400 hPa, and the data up to 300 hPa in the tropics. This is because the radiosonde measuring system isn’t accurate enough to measure changes in humidity in locations where humidity is already at comparatively low levels and because any radiosonde humidity measurements prior to 1973 are unusable as a result of instrumental changes and deficiencies. Paltridge also bases his findings on a combination of observations and models (you know, the things Nova hates). This report – http://www.atmos.umd.edu/~ekalnay/Kistleretal.pdf - notes that “gridded variables, the most widely used product of the reanalysis, have been classified into three classes”; moisture variables, upon which Paltridge would have relied, fall into the category, ‘Type B Variables’, which the report describes as being “influenced both by the observations and by the model, and are therefore less reliable [than Type A Variables which "are generally strongly influenced by the available observations"]“. In addition, on both the NCEP reanalysis website and the NCAR reanalysis website a ‘problem report’ is given, discussing the issues associated with the data. One such issue is titled ‘Spurious Moisture Source/Sink’. In brief, it states that “a poor approximation was used for the humidity diffusion which created spurious moisture sources and sinks”; amongst other things this “can be expected to increase/decrease humidity”. And of course the radiosonde measurements contradict the satellite measurements - http://www.gfy.ku.dk/~kaas/forc&feedb2008/Articles/Soden.pdf -
scaddenp at 08:14 AM on 29 June 2010Abraham reply to Monckton
Awol - "as warm as possible". Why not even more potent GHGs then and get us to Venus-like temperatures? Well obviously because we want planet to be around the temperatures we evolved to live in. However, this debate isnt really about what would be an optimal temperature but is about how fast we are changing it. Think of your farm animals and about how easily farmers are able to cope with rapid climate change. We have huge urban centers and complex food production systems that have developed in stable climate. Rapid change is not good for them. Ask how farmers on the great deltas are going to cope with coast erosion and salt incursion as sealevel rises as well. Over a 1000 years (ice cycle type change) possible. Over 100 years - hmm. -
Peter Hogarth at 08:12 AM on 29 June 2010What causes the tropospheric hot spot?
One of the issues at the heart of the matter is the trend differences between UAH and RSS satellite temperature estimates for the tropical lower and mid troposphere, both based on the MSU (microwave soundings) raw data from various satellites.
Santer 2008 uses data from 1979 to 2000, Bengtsson 2009 uses a similar methodology with (Ocean only) satellite data updated to 2008, and I have updated the satellite trend values to current, with the latest UAH LT5.3 data. All trend value are degrees C per decade.
Santers analysis of the satellite trends and surface temperature and Radiosonde trends to 2000 pointed to a much reduced discrepancy between observations and model outputs than found previously (see figure below). He also suggests where models may be lacking.
Bengtsson 2009 follows on from this but uses the later lower trend values. Based on these and a modeling/statistical approach, the probability of the satellite temperature trends being due to natural causes is given as 27% for the UAH measurements and 2.5% for the RSS measurements. Maybe reasonable odds, but not “robust” yet except perhaps in the case of the RSS trend.
Bengtsson also argues that the UAH values are closer to observed SST, but conversely Santer 2008 suggests the RSS values are closer to other global temperature series, and other interpretations of the MSU raw data. This relatively small RSS/UAH difference weighs heavily.
Bengtsson concludes “Observed and re-analyzed lapse rate trends are all positive and for the period 1979-2008 well outside the range of natural variability”, but in terms of temperature trends, “The present 30-years of tropospheric temperature observations are still insufficient to identify robust trends as the internal variability of realistic climate models is larger than the observed trends”
Has the situation changed since 2008/2009?
A little. The UAH/RSS divergence has reduced with the latest revisions and data, the RSS trend values are slightly lower but the revised UAH tropical trend values have increased (I should mention UAH global trends did not change with the update) so that they are higher than in Santers original analysis. As the trends have continued (ie troposheric temperatures have continued to rise) we would expect that the updated 2010 data will push further towards (rather than away from) any statistically robust result.
The following image is from Santer 2008 and summarises the story of the models and measurements as at 2008 quite nicely.
If you view the JoNova post linked in the article you will see a related but older chart from Santer 2005, which supports the idea of significant divergence despite Jo citing the later 2008 paper in which Santer argues otherwise. Likewise her second figure should be updated in line with more recent work, as science has moved on.
I also have serious concerns about the one later reference which Jo uses (Paltridge 2009) to support a view that tropospheric relative humidity is falling. This is at odds with the conclusions of the bulk of recent papers I have read, and Paltridge himself states “It is accepted that radiosonde-derived humidity data must be treated with great caution” the data is single source (NCEP) re-analysis.
As well as Sherwood 2010a listed earlier, and evidence from Sherwood 2010b, he has also completed a recent review of independent work examining tropospheric water vapour using multiple data sets from several types of sensor Sherwood 2010c which adds a more thoroughly referenced and wide perspective on Tropospheric water vapour:
“Thus, all primary data sets support the conclusion that water vapor mixing ratios in the troposphere are increasing at roughly the rate expected from the Clausius-Clapeyron equation. Although a few analyses have found otherwise, these relied on secondary data sets that are less suitable for quantifying trends”.
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Doug Bostrom at 07:58 AM on 29 June 2010Astronomical cycles
Further to kdkd's comment to Ken, here's an extended quote from a blog post by Michael Tobis I think talks to the whole matter behind this thread, that is to say whether some external influence is going to nullify unrelated processes here on Earth. There is some implication that there is an "AGW theory" and that there is an argument in its support, and that said argument is a cohesive thread starting with Fourier and ending at the dreaded-extremist-boogeyman-Gore, and that failure of any chain in said argument necessarily implies "see, so no carbon policy is necessary". (I'm missing a few steps in their reasoning here, too, but that's another topic still.) I claim there is no "AGW theory" in the sense that there is an argument that four colors suffice, or more fairly, that stars follow an evolutionary path based on their mass. AGW is not an organizing principle of climate theory at all. Hypotheses, organizing principles, of this sort emerge from the fabric of a science as a consequence of a search for unifying principles. The organizing principles of climatology come from various threads, but I'd mention the oceanographic syntheses of Sverdrup and Stommel, the atmospheric syntheses of Charney and Lorenz, paleoclimatological studies from ice and mud core field work, and computational work starting with no less than Johnny von Neumann. The expectation of AGW does not organize this work. It emerges from this work. It's not a theory, it's a consequence of the theory. Admittedly it's a pretty important consequence, and that's why the governments of the world have tried to sort out what the science says with the IPCC and its predecessors. That tends to color which work gets done and which doesn't, and I think it should. As Andy Revkin pointed out, it may be time to move toward a service-oriented climatology, or what I have called applied climatology. The point is that this amounts to application of a theory that emerged and reached mathematical and conceptual maturity entirely independent of worry about climate change. So attacks on climate change as if it were a "theory" make very little sense. Greenhouse gas accumulation is a fact. Radiative properties of greenhouse gases are factual. The climate is not going to stay the same. It can't stay the same. Staying the same would violate physics; specifically it would violate the law of energy conservation. Something has to change. For a little more on what must change, how much, etc. see the rest of Tobis' post. My point in quoting Tobis is to make a helpful reminder that "falsifying" the notion of anthropogenic global warming would require an upheaval of research none of us are going to witness. So don't look to external matters such as the moon and stars or things that make graphs wiggle to put a neat "done" on the matter. -
andrew adams at 07:43 AM on 29 June 2010What causes the tropospheric hot spot?
I was prompted by this post to pay a visit to Jo Nova's site. I don't know much about Ms Nova herself but the comments were a real snake pit - not pleasant. One guy got great satisfaction (and approval from others) by countering the argument that the THS is not specifically a fingerprint of AGW by pointing to the IPCC's statements that tropospheric warming/stratospheric cooling is a fingerprint of AGW. But to my layman's eye they are completely different phenomena and irrelevant to this argument. -
Doug Bostrom at 07:41 AM on 29 June 2010Return to the Himalayas
Thank you for your remarks, Kooiti. You make a fair point about the distinction between the Himalayas and the region covered by Immerzeel. In fact, the title of the article I feature is "Climate Change Will Affect the Asian Water Towers" and I now see that not only does my title not reflect that but I actually managed to -not- mention the article title once in my little writeup. The latter I'll somehow fix but I think I'll leave the title as-is because I think it's helpful to give folks an explicit pointer to updated information behind the Himalaya reference fiasco. Thanks also for your remarks about population details as well as your taking time to supply some pointers for people wanting to go further with that. In a way your points are complementary to mine in that we can see how resolution of this sort of information improves over time. W/regard to Barnett's own issues w/cites as well as "data bruising" as information is passed from one publication to another I have (is it any surprise) an opinion about that but not I think one that is very controversial in terms of intent, though it could become significant when viewed from the perspective of relying on reviews if not handled properly. The least ambiguous and most accurate description of any research paper's content is harbored in the original paper itself. By necessity not all information from a paper is conveyed when another researcher or reviewer dips into a given paper for supporting information and so real diligence must be practiced in this crucial hand-off. Unless the dependency in question is unusually atomic there is room for ambiguity and even error to creep in; ambiguity accompanies insufficient characterization as does error. Authors of reviews and synthesis reports are at the end of a longer foodchain, the information they draw from has passed through more hands and thus is more susceptible to damage. I think it's safe to say this problem of conclusion creep or divergence is one reason why it's such a good thing that IPCC has built what appears to laypersons as a pathologically obsessive review process, drawing on the awareness of publishing scientists of how easy it is to mess up information as it is passed along. Cases of error in spite of fanatical attention to details are a cue to how demanding this process really is. Apparently IPCC is going to amp-up their reviewer scrutiny still farther, a sign of the relative urgency attached to the task of keeping the IPCC synthesis up to date even while drawing on active avenues of inquiry. Time appears of the essence in this case, we don't have 100 years to wait for dust to collect on researchers' work before before being supplied with information to assist with mitigation and adaptation. -
kdkd at 07:33 AM on 29 June 2010Astronomical cycles
KL #105This is a huge burst of heat equivalent; entirely incompatible with the steadily increasing imbalance proposed by CO2GHG theory.
The myth of a monotonic increase is a frequent climate contrarian talking point. The theory has no such requirement. Perhaps this is one for the common arguments page, although the idea that noise exceeds signal over short time periods is so obvious to everyone except the so called sceptics, that it's an argument that's trivial to rebut. -
AWoL at 07:28 AM on 29 June 2010Abraham reply to Monckton
I'm just a vet, though believe it or not, I can remember Boltzman's Constant from our old Physics lectures, so I like to believe that I inhabit the ranks of the scientific semi-literate. My question is, if the Earth has an arbitrary average temperature of circa 15degC and the temperature of space is 270degK ie -270degC, then what's the problem? Anything that stems the ferocious heat loss to the exterior, surely has to be a good thing? Surely the correct thing to do is to pump CO2( or more potent greenhouse gases) into the atmosphere in order to keep the planet as warm as possible? What a nutty idea , I hear you say, but in reply I say....-270degC, out there. Not much chance of too much warming when you're up against that. It's bloody cold out there! -
Kooiti Masuda at 06:51 AM on 29 June 2010Return to the Himalayas
You have not quite come back to the Himalayas, but to the greater mountainous region of the Central Asia. Let us tentatively call it the greater Himalayas. There were actually two problems in the Asian chapter (Chapter 10) of IPCC AR4 WG2. One was the outlook of diminishing glaciers in the (proper) Himalayas in the Section 10.6.2. It was really erroneous. Another thing was the estimate of population who depend on glacier meltwater of the "greater Himalayas". In Section 10.4.2.1, it was written that "Climate change -related melting of glaciers could seriously affect half a billion people in the Himalaya-Hindu-Kush region and a quarter of a billion people in China who depend on glacial melt for their water supplies (Stern, 2007)". Stern Review may be a good reference for economic matters, but not an original reference suitable here. In Stern Review, it appears in Chapter 3 "How climate change will affect people around the world", section "3.2 water", page 63. It refers to the following paper in the Note 23 and it is surely the source of the information. Barnett, T.P., J.C. Adam and D.P. Lettenmaier, 2005: Potential impacts of a warming climate on water availability in snow-dominated regions. Nature, 438, 303 - 309. IPCC AR4 WG2 directly refers to Barnett et al. (2005) in Chapter 3 (Freshwater resources and their management), Sections 3.4.1 (Surface waters) and 3.4.3 (Floods and droughts). The paper by Barnett et al. is a peer-reviewed article. And its estimate of population who depend on meltwater from snow seems to be reasonable, though it is different from the estimate of population who are likely to be affected by decrease of snowpack associated with global warming. But it did not distinguish snowmelt and glacier-melt. But Stern Review and consequently IPCC AR4 WG2 Chapter 10 mis-interpreted it as mainly glacier-melt. Also there is a problem in the paper of Barnett et al. that their numbers about glacial meltwater and population are not fully substantiated by their references 40, 41, 42 and 43. It seems to be an issue of sloppiness in the editorial process of the "Nature" magazine rather than of IPCC. The study by Immerzeel et al. (2010) is very welcome and it will supercede Barnett et al. (2005) in terms of estimate of population who depend on snow and glacier meltwater. But we should note that Immerzeel studied five large river basins. We should also look at inland river basins to the north of the Tibatan Plateau, where glacier meltwater has the largest relative role, though the human population density is relatively low. -
carrot eater at 05:24 AM on 29 June 2010What causes the tropospheric hot spot?
HumanityRules: Read 'short term trend' as referring to the observed high frequency behaviour, all the short term wiggles due to ENSO and whatever else. The jump upwards during an El Nino can be described as a short term trend. I did not find John's phrasing at all confusing, but that's what is meant. We already have known that satellite records have been subject to long-term biases and calculation errors in correcting for the same. They've been continually corrected in UAH, one by one. The remaining differences between UAH and RSS also beckon. Any time you've got satellite drift, or you've got to sew together records from different and non-overlapping satellites (an issue with TSI, isn't it?), you'll have to be careful with long term biases. -
VoxRat at 05:08 AM on 29 June 2010Ocean acidification
BP #68 Specifically with respect to pH, though the subject of this discussion... Your graph doesn't have anything to say about the extent or rapidity of pH changes. I guess when these guys http://www.sciencedaily.com/releases/2009/05/090519111031.htm publish their findings we'll have something to compare current trends with. -
John Russell at 04:56 AM on 29 June 2010Return to the Himalayas
Try feeding yourself WITHOUT using water, Paul Daniel Ash. In a rice field it takes around 2,500 litres of water to grow a single kilogram of rough rice. -
michael sweet at 04:03 AM on 29 June 2010September 2010 Arctic Ice Extent Handicapping Via ARCUS
HumanityRules: One way that scientists show what they know is by making predictions of what they think will happen. If those predictions consistantly show skill then they understand the material. If they have poor predictions that means they have a ways to go to understand the material. The predictions on arctic ice have a big spread and low skill. This shows the rest of us that they have more to learn. We can compare to past predictions (like the 2007 IPCC report) and see that the date of an ice free arctic keeps getting moved forward. Even WUWT now predicts an ice free arctic before the 2007 IPCC report!! That shows the scientists have been much too conservative in the past. What does that suggest about their predictions of ice melt in Greenland? Are they more likely conservative or alarmist? As the years go by the predictions will converge. When they do we will have more confidence in those predictions. I note that none of the estimates predict a return to the ice levels of the 1990's. This tells us something and is a firm prediction. -
Doug Bostrom at 03:53 AM on 29 June 2010Return to the Himalayas
Ding-dong-ding! Paul gets the prize for being first to winnow a New Scientist error. In fairness I think it was down to some ambiguous language in Immerzeel, who refers to "total population" without a reminder that the term refers to the region under scrutiny. I made the same mistake when reading the paper but had the luxury of having time for my intuition to illuminate a caution lamp and consequently check the figure. -
Paul Daniel Ash at 03:38 AM on 29 June 2010Return to the Himalayas
Well, 4.5% of the current world population would be 301,376,432; in forty years it'll be something like 420,000,000. So, math FAIL. Also you can't "feed" yourself using water.. not for long, anyway. -
Doug Bostrom at 03:24 AM on 29 June 2010Tuesday 29 June talk on science blogging at University of W.A.
Thanks for the update John and now go to bed. -
HumanityRules at 02:51 AM on 29 June 2010What causes the tropospheric hot spot?
Why would the satellite temperature record be subject to "spurious long-term biases"? We seem to be happy with the data when it confirms the surface instrument record or when it confirms stratospheric cooling but this mid section of the data is all wrong. It seems horribly convenient. In fact it appears akin to Antony Watts hunt for those badly placed weather stations. -
Doug Bostrom at 02:49 AM on 29 June 2010Return to the Himalayas
Thank you, Johnny. Indeed you're right, I don't know how I missed that; I actually read the Wikipedia article while selecting my analogy. Scurrying to correct it... -
Peter Hogarth at 02:47 AM on 29 June 2010Astronomical cycles
Ken Lambert at 23:50 PM on 28 June, 2010 Sorry to plug this again. Have a look here to see the updated satellite record with the global seasonal variations retained, and further down the comments there's a chart showing SH/NH seasonal variations. The annual rate of rise/fall easily exceeds your figures. It's the overall trends we're talking about. Jason 1 had some issues, not sure if they're fixed. Jason 2 and Envisat are current. -
HumanityRules at 02:40 AM on 29 June 2010What causes the tropospheric hot spot?
31 carrot eater Here's a quote from Johns previous post "Jo Nova doesn't get the tropospheric hotspot" "The result is we expect to see magnified warming trends in the troposphere compared to the surface, both over short intervals (say months to a year) and long intervals (over decades). Indeed over short periods, observations are consistent with expectations - a tropical hot spot" John was first to raise the idea of a short term trend. That is what I was questioning. I'm happy to agree with your post. -
Johnny Vector at 02:38 AM on 29 June 2010Return to the Himalayas
Sorry for the off-topic nitpicking, but you've misspelled "pachinko (パチンコ)" in an otherwise excellent post. (I hope the katakana reproduces in other browsers and machines.) And please don't accuse me of pedanticness. The word is "pedantry". -
Doug Bostrom at 01:45 AM on 29 June 2010Sea level rise is exaggerated
Amending my earlier remarks to Daniel or that is to say supplying necessary detail. Daniel, you're dismissing research performed by workers practicing in several disciplines entailing a myriad of details and knowledge. I'm going to take a flying leap of speculation and say that I don't think you yourself practice in those disciplines. My speculation is informed by my observation that beyond not addressing even such simple matters as the calculation of uncertainties of the conclusions formed in Donnelly, you have not attacked in detail the disciplinary practices employed in selecting and analyzing the samples you sneeringly dismiss as inadequate. If I'm correct and you indeed do not practice in at least the core discipline producing the research you are dismissing, you have an enormous amount of work to to perform before you are capable of usefully critiquing research output in that discipline. That is, unless you are very lucky and find a blatant blunder in the work, and you've not yet even bothered to test your luck. You want me to help you with your critique, but I'm not so arrogant as to imagine I can suddenly take on the attributes of a person who has earned an advanced degree in geology with a strong bent to a narrow part of that discipline involving a wealth of arcane information. Not as an "appeal to authority" but as an indicator of how much work you need to do before you're suitable for producing useful critique of work produced in a specialty discipline, let's take a brief look at a bit of Jeffrey Donnelly's CV. Ask yourself, do you -really- believe you're as well informed on his discipline as is he? B.S. Earth Science, University of Massachusetts M.E.S. Coastal and Watershed Systems, Yale University Ph.D. Geological Sciences, Brown University Mann, M.E., J.D. Woodruff , J.P. Donnelly, and Z. Zhang, submitted, El Nino, Tropical Atlantic Warmth, and Hurricanes Over the Past 1500 Years, Nature. *Boldt, K.V., P. Lane, J.D. Woodruff, and J.P. Donnelly, submitted, Sedimentary evidence of hurricane-induced coastal flooding in southeastern New England over the last two millennia: Geophysical Research Letters. *Newby, P., J.P. Donnelly, and B.N. Shuman, 2009, Evidence of centennial-scale drought from southeastern Massachusetts during the Pleistocene/Holocene transition: Quaternary Science Reviews (in press). Shuman, B.N., P. Newby, and J.P. Donnelly, 2009, Abrupt Climate Change as a Catalyst of Ecological Change in the Northeast U.S. throughout the Past 15,000 Years: Quaternary Science Reviews (in press). Madsen A.T., G.A.T. Duller, J.P. Donnelly, H.M. Roberts, and A.G. Wintle, 2009, A chronology of hurricane landfalls at Little Sippewissett Marsh, Massachusetts, USA, using optical dating: Geomorphology (in press). *Woodruff, J.D., J.P. Donnelly, and A. Okusu, 2009, Exploring typhoon variability over the mid-to-late Holocene: Evidence of extreme coastal flooding from Kamikoshiki, Japan: Quaternary Science Reviews (in press). *Woodruff, J.D., J.P. Donnelly, K. Emanuel, and P. Lane, 2008, Assessing sedimentary records of paleo-hurricane activity using modeled hurricane climatology: Geochemistry, Geophysics, Geosystems v. 9, Q09V10, doi:10.1029/2008GC002043. Donnelly, J.P., and L. Giosan, 2008, Tempestuous Highs and Lows in the Gulf of Mexico: Geology, v. 36, p. 751-752. *Woodruff, J.D., J.P. Donnelly, D. Mohrig, and W. R. Geyer, 2008, Reconstructing relative flooding intensities responsible for hurricane-induced deposits from Laguna Playa Grande, Vieques, Puerto Rico: Geology, v. 36, p. 391-394. *Carlson, A., J. Stoner, J.P. Donnelly, and C. Hillaire-Marcel, 2008, Response of the southern Greenland Ice Sheet during the last two deglaciations: Geology, v. 3 6, p. 359-362. *Ashton, A., J.P. Donnelly, and R. Evans, 2008, A discussion of the potential impacts of climate change on the shorelines of the Northeastern USA: Mitigation and Adaptation Strategies for Global Change, doi: 10.1007/S11027-007-9124-3. Cheung, K. F., L. Tang, J.P. Donnelly, E. Scileppi, K. Liu, X. Mao, S.H. Houston, and R.J. Murnane, 2007, Coastal Overwash Modeling in Paleotempestology: Journal of Geophysical Research, v. 112, F03024, doi:10.1029/2006JF000612. Donnelly, J.P., and J.D. Woodruff, 2007, Intense hurricane activity over the past 5,000 years controlled by El Nino and the West African monsoon: Nature, v. 447, p. 465-468. Hill, J.C., N.W. Driscoll, J. Brigham-Grette, J.P. Donnelly, P.T. Gayes, and L. Keigwin, 2007, New evidence of very high discharge to the Chukchi shelf since the Last Glacial Maximum: Quaternary Research, v. 68, p. 271-279. *Scileppi, E., and J.P. Donnelly, 2007, Sedimentary Evidence of Hurricane Strikes in Western Long Island, New York: Geochemistry, Geophysics, Geosystems, v. 8, Q06011, doi:10.1029/2006GC001463. Thieler, E.R., B. Butman, W.C. Schwab, M.A. Allison, N.W. Driscoll, J.P. Donnelly, and E. Uchupi, 2007, A catastrophic meltwater flood event and the formation of the Hudson Shelf Valley: Palaeogeography, Palaeoclimatology and Palaeoecology, v. 246, p. 120-136. Keigwin, L., J.P. Donnelly, M.S. Cook, N. Driscoll, J. Brigham-Grette, 2006, Rapid Sea-Level Rise and Holocene Climate in the Chukchi Sea: Geology v. 34, p. 861-864. Donnelly, J.P., 2006, A Revised Late Holocene Sea-Level Record for Northern Massachusetts, USA: Journal of Coastal Research, v. 22, p. 1051-1061. Giosan, L., J.P. Donnelly, S. Constantinescu, F. Filip, I. Ovejanu, A. Vespremeanu-Stroe, E.Vespremeanu, G.A.T. Duller, 2006, Young Danube delta documents stable Black Sea level since the middle Holocene: Morphodynamic, paleogeographic, and archaeological implications: Geology, v. 34, p. 757-760. Shuman, B., and J.P. Donnelly, 2006, The Influence of Seasonal Precipitation and Temperature Regimes on Lake Levels in the Northeastern United States during the Holocene: Quaternary Research, v. 65, p. 44-56. Donnelly, J.P., 2005, Evidence of Past Intense Tropical Cyclones from Backbarrier Salt Pond Sediments: A Case Study from Isla de Culebrita, Puerto Rico, USA: Journal of Coastal Research, SI42, p. 201-210. Giosan, L., E. Vespremeanu, J.P. Donnelly, J. Bhattacharya, and F. Buonaiuto, 2005, Morphodynamics and evolution of Danube delta: Journal of Sedimentary Research, SP 83, p. 391-410. Shuman, B., P. Newby, J.P. Donnelly, A. Tarbox, and T. Webb III, 2005, A Record of Late-Quaternary Moisture-Balance Change and Vegetation Response from the White Mountains, New Hampshire: Annals of American Association of Geographers, v. 95, p. 237-248. Donnelly, J.P., Driscoll, N., Uchupi, E., Keigwin, L., Schwab, W., Thieler, E.R., Swift, S., 2005, Catastrophic Meltwater Discharge down the Hudson River Valley: A Potential Trigger for the Intra-AllerØd Cold Period: Geology v. 33, p. 89-92. (Research Highlight: Nature 17 February 2005 433: 702) Donnelly, J.P., and Webb III, T., 2004, Backbarrier sedimentary records of intense hurricane landfalls in the northeastern United States. In: Murnane, R. and Liu, K. (eds.), Hurricanes and Typhoons: Past Present and Potential, New York: Columbia Press, pp. 58-96. Donnelly, J.P., J. Butler, S. Roll, Micah Wengren, and T. Webb III, 2004, A backbarrier overwash record of intense storms from Brigantine, New Jersey: Marine Geology, v. 210, p. 107-121. Donnelly, J.P., Cleary, P., Newby, P., and Ettinger, R., 2004, Coupling Instrumental and Geological Records of Sea-Level Change: Evidence from southern New England of an increase in the rate of sea-level rise in the late 19th century: Geophysical Research Letters, v. 31 L05203 doi:10.1029/2003GL018933. Donnelly, J.P., and M.D. Bertness, 2001, Rapid shoreward encroachment of salt marsh cordgrass in response to accelerated sea-level rise: Proc. Nat. Acad. Sci., v. 98, p. 14218-14223. Donnelly, J.P., S. Roll, M. Wengren, J. Butler, R. Lederer, and T. Webb III, 2001, Sedimentary evidence of intense hurricane strikes from New Jersey: Geology, v. 29, p. 615-618. Donnelly, J.P., S. S. Bryant, J. Butler, J. Dowling, L. Fan, N. Hausmann, P. Newby, B. Shuman, J. Stern, K. Westover, and T. Webb III, 2001, A 700-Year sedimentary record of intense hurricane landfalls in southern New England: Geological Society of America Bulletin, v. 113, p. 714-727. (editors’ choice: Science 8 June 2001 292: 1801) Donnelly, J.P., T. Webb III, and W.L. Prell, 1999, The influence of accelerated sea-level rise, human modification and storms on a New England salt marsh: Current Topics in Wetland Biogeochemistry v. 3, p.152-160. Donnelly, J.P., 1998, Evidence of late Holocene post-glacial isostatic adjustment in coastal wetland deposits of eastern North America: Georesearch Forum, v. 3-4, p. 393-400. -
chris at 01:25 AM on 29 June 2010Astronomical cycles
Ken Lambert at 23:50 PM on 28 June, 2010 Well yes Ken, that's the point. You chose to make a great deal out of an apparent slow down in sea level rise. My point is that one cannot make profound interpretations from a very short period of data. After all if you wish to assert that the apparent slow down is significant then you can't really choose to ignore an equivalent apparent speed-up in sea level rise. We don't know to what extent these apparent slow downs and rises are fully real (they’re certainly at least partly real; see below). Overall the data continue to be compatible with a continuing trend in sea level equivalent to a rise somewhat above 3 mm.yr-1. This is wrong: "...entirely incompatible with the steadily increasing imbalance proposed by CO2GHG theory. If by "CO2GHG theory" you mean the rather well-founded expectation that the earth surface temperature will rise under the influence of a radiative imbalance towards a new equilibrium temperature around which it will fluctuate as a result of natural variability (i.e. the theory of enhanced greenhouse forcing), there isn't anything necessarily incompatible with the observed sea level rise data. It would be a fundamental misunderstanding to think that there should be anything necessarily "steady" about the progression of manifestations of radiative imbalance particularly when assessed over short periods. One needs to consider: (i) measurement errors. These are smaller for sea level rise measurements than for ocean heat content (OHC) measures, but they are significant as is obvious from inspection of the data . This is always a good reason for preferring longer term trends over very short time periods. (ii) real short term variability. This is likely to be large [*]. And of course we know this from simple inspection of the data. Natural variability will enhance the apparent greenhouse-forced sea level rise during some periods (El Nino, solar cycle, reduced albedo), and during other periods suppress the apparent sea level rise (La Nina, solar cycle, enhanced albedo, volcanic activity). Overall this natural variability will more or less reduce to near-zero with respect to trends. Therefore if we wish to make profound interpretations about trends, we obviously choose to assess the progression of parameters over longish periods in which this variability is averaged out. [*] For example, the redistribution of ocean heat during El Ninos and La Ninas can have very large temporary effects on sea level. It’s not unheard of the have a short term (year or so) rise of 10-15 mm.yr-1 during strong El Ninos, and largish sea level decreases during La Ninas. It’s dumb to pretend that these effects don’t occur, or to ignore them when attempting fundamental interpretations about responses to radiative imbalances. -
Doug Bostrom at 01:02 AM on 29 June 2010Sea level rise is exaggerated
Let me explain why you need to do the work or must instead pipe down, Daniel. Any bachelor degree graduate can ... The Donnely paper...is simply an utter joke. Scientists who after having found the time and inclination to review the data of climate scientists are utterly apalled at the conclusions drawn. Those words are what is known as the "Badge of Hubris." You have said you believe the work you're criticizing to be defective, you have said that "any bachelor degree graduate" can show why. You have spoken for a number of scientists you claim are appalled. The problem is, you've not yet earned your Badge of Hubris because you have not shown exactly what is wrong with the authors' conclusions. Where are their ranges of uncertainty incorrect, how did they calculate that incorrectly, for instance? "I doubt it" is not an argument that can earn you the Badge of Hubris. Your demand that I supply the detail required to make your argument earns a Badge of Comedy. You're the person flinging assertions, support 'em or pipe down. Simple enough, right? -
Riccardo at 00:39 AM on 29 June 2010What causes the tropospheric hot spot?
Berényi Péter, I wrote "following that paper", so it's not my idea but the results shown there. Anyways the answer to your question I think is no, but it's not clear to me where it comes from. Explaining the band (their fig. 3a) of negative correlation in the southern ocean the paper says: "negative correlation of γ with Ts can be attributed to a combination of the thermally inertial ocean and quite strong variations in the annual cycle of temperature at the top of the troposphere (with relatively small variations in surface temperature)." In other words it appears to be due to the annual cycle and to the associated changes in atmospheric circulation. When talking about the so called tropical hot spot one usually refers to the multi-year trend of the anomaly, which is not the same as what is shown in Mokhov et al. paper. -
Alexandre at 00:29 AM on 29 June 2010Perth event tonight: public forum on climate change
I'll definetely download it afterwards. -
SNRatio at 00:13 AM on 29 June 2010What causes the tropospheric hot spot?
First, I wonder if not the enhanced spikes in tropospheric temps relative to surface temps during El Ninos (see e.g. http://www.woodfortrees.org/plot/uah/...) could be illustration of the short term phenomena in question. (Not "trends".) Second, the denialist position is logically flawed in this case, too. For what happens to GW if the hot spots don't get very hot? As carrot eater related, there are two feedbacks in operation, a positive WV and a negative LR. Nothing much happens with the positive vapor feedback, BUT the negative lapse rate feeback, which is quite significant in GW, becomes much weaker without hot spots. (It does by no means disappear, though.) SO, the net effect, everything else equal, will be that the same amount of forcing will produce MORE warming without hot spots. Consequently, unless balanced by other effects, data speaking against hot spots are arguments for higher sensitivity. -
Ken Lambert at 23:50 PM on 28 June 2010Astronomical cycles
Chris #100 I have not had time to go back to the prior sea level discussion, being away for a few days. It should be noted however that the very fact that there was an 'apparent' slowdown of the rise in the 2006-2008 period observed by Jason, followed by an impossible 6.5 mm/year to date; does indicate an unexplained variability in either the sea level or the Jason measurement. We are talking global sea level rise jumping from around 2mm to 6.5mm per year. This is a huge burst of heat equivalent; entirely incompatible with the steadily increasing imbalance proposed by CO2GHG theory. It would imply a thermal expansion rise of 3-4mm/year which is equivalent of about 280E20 Joules/year which is double Dr Trenberth's 145E20 Joules /year 'observed' by his 0.9W/sq.m TOA imbalance. Explaining this a noisy data might be credible if it applied to a part of the biosphere where the sum of the other parts even themselves out; but it is scarcely credible globally; for the whole of the planet. -
carrot eater at 23:49 PM on 28 June 2010What causes the tropospheric hot spot?
Humanity Rules, You are all twisted up here. Nobody is talking about "short term trends associated with AGW". That doesn't even have meaning. We're talking about the short term variability, related to El Nino, La Nina, etc. Compare some satellite and surface records. You'll see, for example, the El Nino peak of 1998 is more exaggerated in the satellite records than it is in the surface records. That's the sort of thing being discussed here. Or, for a more careful analysis, just look at the linked papers. Remember, the 'hot spot' is not unique to greenhouse gases. It should exist, no matter what caused the surface to be warmer - including internal variability like ENSO. -
Jim Eager at 23:32 PM on 28 June 2010Perth event tonight: public forum on climate change
Chris, unfortunately we're stuck with the fossil fuel energy source we have until we can build it's replacement, which means for the time being we have to burn fossil fuels to build that replacement. The more rapidly we build that replacement the sooner we can ratchet down using those fossil fuels. This is actually a very powerful argument in countering those who seek to delay taking action to construct a new energy infrastructure: if we wait until after peak oil it will 1) cost more, 2) we risk not having enough fossil fuel to build it in time, and 3) we will shift to coal, which insures that we will have less time. -
HumanityRules at 23:27 PM on 28 June 2010September 2010 Arctic Ice Extent Handicapping Via ARCUS
SEARCH seems proud of the headlines it can generate. -
HumanityRules at 23:22 PM on 28 June 2010September 2010 Arctic Ice Extent Handicapping Via ARCUS
58 chris this seems a little unfair. SEARCH is organised by mainstream arctic scientists and seems to garner participation from many mainstream arctic science groups. If it's little more than a game (no doubt generating headlines) then maybe these serious scientists shouldn't be participating. If we want less blogospheric hot air we should insist that scientist stick to what we (i.e. they) know. -
HumanityRules at 23:11 PM on 28 June 2010What causes the tropospheric hot spot?
26 carrot eater It's not the failure to find a long term trend that I'm concerned about but how, in a highly variable data set, we can see the short term trends. Presumably these short term trends associated with AGW are also an order of magnitude below the variability unless the short term trend is an order of magnitude greater than the expected trend, which seems unlikely. -
KR at 23:08 PM on 28 June 2010Accelerating ice loss from Antarctica and Greenland
I hope those 5000 D cells are rechargeables! -
Berényi Péter at 23:03 PM on 28 June 2010What causes the tropospheric hot spot?
#27 Riccardo at 22:30 PM on 28 June, 2010 the lapse rate feedback is negative in the tropics but postive overall Let me understand. Are you saying with increasing surface temperatures overall rate of evaporation increases but the area where this happens decreases? -
Alexandre at 22:37 PM on 28 June 2010What causes the tropospheric hot spot?
Thanks for the post, John. This was something I've been struggling to understand, too. -
Berényi Péter at 22:32 PM on 28 June 2010Ocean acidification
#67 VoxRat at 20:34 PM on 28 June, 2010 ecosystems that have adjusted to current conditions over millions of years Global climate went crazy about 3 million years ago and the instability due to the general cooling trend is getting ever worse. Like a bad case of microphone whine. Current ecosystems are adjusted to this ever changing environment. It is part of the reason humans could afford to have an oversized brain in spite of its huge energy costs and cooling problems. If conditions are kept constant, there is no point whatsoever in being able to figure out what to do in case conditions would change.
Keep in mind that all the endangered coral reefs of the world are substantially younger than twenty thousand years. Eighteen thousand years ago present day reef sites were on high ground, 120 m above sea level. That; and the arithmetic fact one hundred fifty times twenty thousand makes three million.
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Riccardo at 22:30 PM on 28 June 2010What causes the tropospheric hot spot?
Berényi Péter, the hot spot is called tropospheric for a reason. And this is from the article you cite: "The correlation of γ with Ts is negative in the equatorial latitudes and midlatitudes over the oceans." Hence, following that paper the lapse rate feedback is negative in the tropics but postive overall, more so at the high latitudes. -
daniel at 22:26 PM on 28 June 2010Sea level rise is exaggerated
Doug why don't you explain the detail required? I have provided all the detail nessecary. A short term trend of ~150 years, measured using direct measurement techniques at high resolution is compared to a general linear trend over ~550 years approximated using 10 paleo data points with clearly alot of uncertainty in each. There is no statistics to "undo" can you explain what you mean by that? I doubt only the conclusions section of the paper. 10 noisy data points do not adequately measure sea level trends at the 150 year time scale between 1300-1850 AD. Therefore it is invalid to conclude there has been a significant recent increase in seal level rise. As I mentioned in my previously deleted comment both you and peter have put words in my mouth by claiming I doubt the methods or error analysis of the Donnely paper or reffered to a "downturn" in recent sea level trends (good one pete). You're nit even listening to what I am saying. Which is a reflection on your credibility not mine. -
carrot eater at 21:56 PM on 28 June 2010What causes the tropospheric hot spot?
HumanityRules, I think you might be confusing some matters. Maybe read the links put there, like this one http://pubs.giss.nasa.gov/docs/2005/2005_Santer_etal.pdf The surface record shows a lot of short-term variability, and that variability is even stronger in the troposphere. But given that large variability, and the quality of the observations, it is difficult to observe any long term trends. -
chris1204 at 21:52 PM on 28 June 2010Perth event tonight: public forum on climate change
A question I'd love to put to Dr Oschmann relates to the carbon footprint involved in making the transition to a clean-energy future? Eg, we still have to power the machinery to mine the ore to build our wind turbines, generate CO2 while we make cement to build the infrastructure, etc. The answer might well turn out to be 'very small' which would be very welcome news. Notwithstanding my propensity to curmudgeonly contrarianism, I genuinely believe we need to reduce our reliance on fossil fuel would prefer to see us pumping much less CO2 into the environment. Best wishes for the evening.Response: Volker just emailed me a response to this question:“A recent comprehensive study (Almut Kirchner et al, “Blueprint Germany, A strategy for a climate-safe 2050”, Basel/Berlin 2009) argues that it is possible to reduce greenhouse gas emissions in Germany by 95 percent by 2050 (compared to 1990). This includes emissions to build the infrastructure necessary for the transition. An English version of the study can be found here."
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Berényi Péter at 21:36 PM on 28 June 2010What causes the tropospheric hot spot?
The paper below observes a global 0.7% increase in lapse rate for a 1 K warming of surface. It means high above the ground the temperature anomaly should vanish (this surface is supposed to be at a much lower level above the poles than above low latitudes). They also say lapse rate is about 6.5 K/km at low latitudes and 4.5 K/km at the polar region, which is roughly consistent with the 0.7% figure (implies a 52.7 K difference in surface temperatures between poles and tropics, which is reasonable). How is it consistent with your statement ˇ"When the surface warms, there's more evaporation and more moisture in the air. This decreases the lapse rate - there's less cooling aloft. This means warming aloft is greater than warming at the surface. This amplified trend is the hot spot"? A detailed explanation would be welcome. Izvestiya Atmospheric and Oceanic Physics Volume 42, Number 4 / July, 2006, pp. 430-438 DOI: 10.1134/S0001433806040037 Tropospheric lapse rate and its relation to surface temperature from reanalysis data I. I. Mokhov and M. G. Akperov -
Byron Smith at 21:25 PM on 28 June 2010Perth event tonight: public forum on climate change
Sounds like a good event. I hope the distinction between the science and the policy is made clear many times throughout the night. I fear that much of the angst about the science is really angst about policy options and people assume they are identical (i.e. if you accept the science, then there is only one policy option). -
Tenney Naumer at 21:25 PM on 28 June 2010Perth event tonight: public forum on climate change
Best wishes for a successful discussion! -
HumanityRules at 21:08 PM on 28 June 2010What causes the tropospheric hot spot?
John, There are a couple of points in your article that I'd like considered together because they are causing me some concern. 1) "the hot spot is well observed over short timescales". (I assume you mean the trend here not just the fact the hot spot exists) 2) "the short-term variability is nearly an order of magnitude greater than the long-term trend" I wonder to what extent you can be confident of the first fact given the existence of the second. How can we be sure that the short term trend is not just a happen-chance product of this natural variability? In many other aspects of climate it seems appropriate to be wary of short term trends for this very reason.Response: Short-term trends are totally due to internal variability. Eg - El Nino. So what we observe is the surface temperature ups and downs due to El Nino are magnified in the tropical troposphere. -
VoxRat at 20:34 PM on 28 June 2010Ocean acidification
Arkadiusz Semczyszak #65 "“... a rapid recovery of coral reefs in areas of Indonesia, following the tsunami ... [2004 -2009]” Because some ecosystems can recover rapidly from some kinds of damage is not much of a case that a global acidification of the oceans is nothing to worry about. "As was the myth about the current rapid [change] of abnormal pH" What "myth" is that, exactly? "I recommend: http://omniclimate.wordpress.com/2009/02/04/a-shell-game-behind-ocean-acidification/ " Yes. I think we all agree that there have been times in the past when atmospheric [CO2] (and presumably ocean-surface acidity) were considerably higher. And we all agree that life can survive even under the extreme conditions of deep ocean volcanic vents. No one is saying CO2-induced acidification (or temperature rise, or anything else) is going to sterilize the planet. The point is: what happens when you abruptly change critical parameters (like pH, Omega-arag, and temperature) to ecosystems that have adjusted to current conditions over millions of years? I'm not so confident, as you appear to be, that the answer is "nothing much". -
Arkadiusz Semczyszak at 19:35 PM on 28 June 2010Ocean acidification
"... growth ..." - of course not pH but change of pH -
Megan Evans at 19:03 PM on 28 June 2010Perth event tonight: public forum on climate change
Sounds great! And also great that it's being recorded.
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