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

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Comments 78201 to 78250:

  1. apiratelooksat50 at 04:47 AM on 1 August 2011
    Rising Oceans - Too Late to Turn the Tide?
    Muon@50 Well, obviously moving away from the water's edge as it continues it's inexorable creep upwards is a start. That is until the next ice age starts and then the land can be reclaimed. It's not "we can adapt", it's about "we must adapt." I am interested in hearing your ideas.
    Response:

    [DB] "Well, obviously moving away from the water's edge as it continues it's inexorable creep upwards is a start. That is until the next ice age starts and then the land can be reclaimed."

    So your suggestion is to walk uphill for the next 60,000+ years...some, obviously, will run out of "uphill" and will need a boat...

  2. Ocean Cooling Corrected, Again
    Hi Rob @68, Re the divergence. I'm not sure-- a problem with the ARGO data post 2009?
  3. Ocean Cooling Corrected, Again
    BP has still not acknowledged and corrected his colossal error @9 (an error that is still being happily perpetuated by fellow "skeptics" despite it being brought to their attention a couple of times up thread),and BP has also repeatedly ignored the challenge made to him by KR and me to "As Albatross asked earlier, do you have any peer reviewed references that contradict Von Schuckmann and Le Traon 2011?. Instead, we get more pontification and hand waving from BP....this pattern by "skeptics" of hi-jacking threads and throwing them off topic is becoming incredibly tiresome.
  4. Berényi Péter at 01:43 AM on 1 August 2011
    Ocean Cooling Corrected, Again
    #42 Rob Painting at 21:29 PM on 29 July, 2011 They [Von Schuckmann and Le Traon] use a more complete dataset and different analysis (infilling missing profiles with 'averaged anomalies' as opposed to zero anomaly infilling employed by Lyman et al for instance) and measure deeper into the ocean. 10-1500 metres, you will note, includes 690 metres of the top 700 metres of ocean. That's not the point. Both Levitus and Schuckmann provide error bars for their estimates. If these are correct, the 0.39 ± 0.07 W/m2 average of the latter study for period 2005-2010 and depth range 10-1500 m can be divided to 0.14 ± 0.06 W/mm2 imbalance for the upper 700 m and 0.25 ± 0.09 W/mm2 for the rest (700-1500 m). It means almost twice as much heat went into the lower layer then into the upper one, while their mass is pretty similar. It begs some explanation, doesn't it? This derivation does not depend on the details of the two studies, just on the estimates and error bars, and on the assumption their errors are independent of each other. If it is your opinion that the Levitus data are flawed in some manner and their estimate (including error bars) for the upper 700 m is off, please say so. And, of course, substantiate your claim. By the way, it would be much easier to evaluate the paper if they provided that breakdown themselves in units directly comparable to those used in other studies or at least published their supplementary data & algorithms online that could be used to do the job independently. Unfortunately they have chosen another course. _ While we are into this OHC thing, some words about how on earth can heat get down to the abyss at all are in order. The first thing to note is that the MOC (Meridional Overturning Circulation) is not a heat engine. That is, it does not convert temperature differences into mechanical energy to keep ocean currents moving, but it is the other way around. It depends on some external mechanical energy source to maintain circulation and redistribute heat. If a body of fluid in a gravitational field (like the oceans) is both heated and cooled at different places but at the same gravitational potential (e.g. at the surface on low and high latitudes respectively), that would not produce any macroscopic flow whatsoever. There are two caveats to this proposition. 1. Visible light (sunlight) and especially UV can penetrate into the ocean to some depth (a couple of hundred meters at most), so heating in fact happens at a somewhat lower geopotential than cooling, which is restricted to the surface (down to several meters, if waves are taken into account). But it would provide for a very shallow circulation only, not the kind of deep overturning observed. Also, it is worth noting that thermal infrared ("back radiation") can not penetrate into seawater at all (several mm at most). 2. There is also heating at depth, by geothermal heat flux, which is about 0.1 W/m2 averaged over the entire seafloor (and 0.04 W/m2 over the continents). In some regions (for example at the boundaries of the Nazca plate, South Eastern Pacific) it can be as high as 0.3 W/m2. This heating happens at the right geopotential (at the bottom), so it does produce overturning, albeit at a much slower rate than observed. Needless to say heat conductivity of seawater is so low, that by conduction alone (with no macroscopic flow) it would take ages for heat to get down to the abyss from the surface. There are parts of MOC that work as a heat engine indeed. Downwelling of cold saline water in polar regions is such an exception. However, if there were no other processes at work in other regions, the abyss would eventually get saturated with very cold water of high salinity and downwelling would stop altogether. Or rather, it would switch to the much slower rate permitted by geothermal heating alone. We should also note this part of the so called thermohaline circulation does not add heat to the abyss, but removes it from there. Currently deep water production is restricted to two distinct regions of the oceans. One is where the North Atlantic joins the Arctic ocean, the other is along the Antarctic coastline. In theory it could also happen in the North Pacific, but in fact it does not, for the salinity is too low there and the coastline is not cold enough. Details of the physics are somewhat different in the North and the South though. The North Atlantic Drift carries ample quantities of warm, highly saline water into the Arctic ocean (the high salinity is leftover of evaporation), which cools down there and when it gets next to freezing (the most dense state of seawater), it sinks. It is an intermittent process, restricted to "chimneys" (of diameter ~100 km and lifetime of several weeks) in the open ocean. Please note the heat carried to the polar region this way is lost to the atmosphere entirely, the cold saline water sinks to the bottom without it. This heat subsequently is radiated out to space, as that is the only heat reservoir around which is colder (-270°C). Antarctica is a special place. No warm current gets near to the continent, so salinity of seawater there is inherently lower than in the Northern Atlantic. On the other hand along the coastline, especially in winter, extremely cold gale force katabatic winds descend from the plateau creating polynyas (open water expanses) by blowing sea ice away. High chilly winds coupled with open water provide for vigorous cooling of water masses (because total area of air-sea interface is huge, think of sea spray) and as sea ice starts to form, salinity also increases by brine exclusion. Cold dense water then descends to the abyss along the continental slope. At the underside of great Antarctic ice shelves even super-cooled water is formed. Its potential temperature is below freezing, that is, it only stays fluid because of pressure, it would freeze if raised to the surface. In general abyssal water of Antarctic origin is somewhat colder but less salty than its Arctic cousin. But still, we need an energy source to keep the engine going. In other words, abyssal waters have to be warmed up and diluted in order to be able to raise somewhere and make room for more cold, dense polar water. The process that does exactly that is supposed to be deep turbulent mixing, driven by external mechanical energy sources like tides and winds. Tidal forcing is a considerable source of mixing, but it is deterministic and independent of all other forcings on climate. It is also cyclic, not exactly, but close enough. The Metonic cycle (the period the National Tidal Datum Epoch [NTDE] of the U.S. is based on) is 19 years long. Or more precisely it is 235 synodic months which is 1h 38' longer than 19 tropical years. The nodal cycle of lunar orbit happens to be only slightly shorter than that (18.5996 years). It means if one is looking for trends in deep turbulent mixing, it is best to consider multiples of the Metonic cycle. Epochs shorter than that (like 6 years) are to be considered as a last resort only if one does not have data with longer timespan. Even then some caution is in order, to filter out tidal effects on trends as much as possible (the same is true for sea level studies). The other source is internal waves excited by winds. One can see that distribution of wind power is extremely uneven on the surface of Earth. It is concentrated in three regions, the Southern ocean, the Norh Pacific and the Norh Atlantic. Of these winds in the south are the most intense by far (and surprisingly mild over the continents). The only problem remaining is that in the open ocean turbulent mixing is measured to be at least an order of magnitude smaller than needed to maintain the observed flows in MOC. The solution seems to be there are narrow regions where topography of the bottom is very complex, like over mid ocean ridges or certain rugged continental slopes where deep turbulent mixing can be up to two, sometimes even three orders of magnitude higher than average. However, these sites are poorly known and most are not even identified yet. So, the very energy source driving MOC and making thermohaline downwelling possible is not well constrained. It is also one of the (many) weak points of GCMs (General Circulation Models). This process is represented in them only through parametrization and even if we knew much better the process going on in real oceans, their too coarse resolution could not accommodate to the small scale vigorous and probably intermittent mixing which characterizes it. Anyway, the take home message is that MOC (Meridional Overturning Circulation), consequently heat exchange between the surface and abyss is not driven by temperature differences, but external mechanical energy sources. Of course winds (unlike tides) are not independent of climate (they are driven by a heat engine, as the atmosphere is mostly heated from below and cooled from above), but in this respect one has to study winds over the southern ocean first (roaring forties & stormy fifties), as according to some estimates up to 80% of deep turbulent mixing happens here (or rather, in restricted sub-regions of it). Therefore if one is interested in heat transport to the lower layers of oceans, one should pay close attention to those remote and alien waters.
  5. Ocean Cooling Corrected, Again
    Albie - check out the graph at @ 62. Are you thinking what I'm thinking? (Hint: the divergence)
  6. Ocean Cooling Corrected, Again
    Albie @ 64 - Whoops, corrected. The funny thing is the 1/58th thing (note no error bars) is actually discussed in Leuliette & Miller (2011). Of course BP's calculations and linear mindset fail to account for the large annual fluctuations in both SLR and the steric component. I guess they can't be happening either?
  7. Ocean Cooling Corrected, Again
    Hi Rob @65, We cross posted, and then I saw that we have both identified the same glaring error in their reasoning....
  8. Ocean Cooling Corrected, Again
    Ken @63, "Land Ice melt was equal to a mass increase +3.1mm/yr" Wrong. You and BP are misrepresenting Rignot et al.'s (2011) results.
  9. Ocean Cooling Corrected, Again
    KL - BP was pointing out that three sea level equivalent measures were inconsistent with the oceans gaining heat." Which is inconsistent with direct observations from the ARGO thermometers, and with published studies. Land Ice melt was equal to a mass increase +3.1mm/yr, Satellite SLR was equal to +2.3mm/yr so therefore steric rise must be negative (-1.1mm/yr if isostatic rebound is included) The Rignot (2011) paper cited by BP says this: "In 2006, the Greenland and Antarctic ice sheets, experienced a combined mass loss of 475 ± 158 G t /y r , equivalent to 1.3 ± 0.4 mm/yr sea level rise." How do we get from that, to BP's 3.1mm per year? "Therefore these measurements do not support a rise in OHC. Yes, but they're BP's calculations. What more can I say? You at #61 are now supporting the point with references that in last interglacial the large mass rise from Antarctica occurred with a negligible steric rise. Very relevant methinks. It suggests that the ice sheets are going to dominate SLR in the future. In fact a recent paper on the new ice sheet models indicate it's too late for the Greenland Ice Sheet. But remember that the last interglacial was due to orbital factors- CO2 was much lower than today. In comparison the increased Greenhouse Effect will last for centuries, the oceans will continue to soak up heat for a very long time until equilibrium is reached. The current slow-down is only temporary I suspect, and largely due to global dimming and a decline in the radiative forcing over the last decade. From a physics-based point of view it makes sense, less solar radiation reaching the sea surface from the aerosols, and associated cloudiness, causing the heat uptake (daytime phenomenon) to slow-down. But the increased Greenhouse Effect has altered the thermal gradient in the ocean skin layer slowing the leakage of heat back into the atmsosphere. It will persistently warm for centuries.
  10. Ocean Cooling Corrected, Again
    Rob @61 and 62, Thanks Rob, very interesting and not much reason to support BP's optimism that the alleged current rate of warming of 0.02 C/decade will continue, well he does not say how long he expects that to continue for, but given that he can "live" with that, one can probably assume it is on the order of decades. These vague, non-committal statements made by "skeptics" are really not helpful or constructive. "The thermal component on sea level rise does appear to have declined in the last decade" I think that you meant to say for the 2005-2010 period the steric contribution may have leveled off or decreased slightly (at least according to Leuliette and Willis, 2011) but is is difficult to say b/c of the relatively large error bars (there is so much overlap when one allows for uncertainties)-- all the more reason not to be making bold assertions that the "oceans are cooling" or that there is a "fundamental inconsistency in the AGW science" based on 5-6 years of noisy data derived from different observations platforms. As I mentioned earlier, Hansen et al. (2011) has also done some accounting for 2005-2010, and his number are very different from the amateur efforts here. Here are the estimated ranges in relative contributions for the 2005-2010 period: Ice melt: +1.27 to + 2.4 mm/yr Abyssal oceans and southern oceans: 0.156 mm/yr Steric rise: +0.55 to 0.83 mm/yr Total: +2.0 mm/yr to +3.4 mm/yr (mean near +2.7 mm/yr). Now, satellite GSL increase for the same period was +1.4 to +3.0 mm/yr (mean +2.2 mm/yr), data from Leuliette and Willis (2011). Pretty good agreement given the limitations of the observations. Now consider the that 'skeptics' here are alleging that for the same period the steric contribution was significantly negative (??)...well, two published papers by experts in the field disagree with that nonsensical assertion. PS: And this claim "however as BP pointed out if you can concentrate the heat into melting land ice - you only need 1/58th the amount to get a unit rise in sea level compared with thermally expanding the oceans.", seems to support the findings of the works that you cited concerning GSL during the last interglacial, not challenge them.
  11. Rising Oceans - Too Late to Turn the Tide?
    scaddenp#51: "it's not hard to make an assessment for what 50-80cm of sealevel rise will do locally." Those sorts of assessments already exist: The impact of sea level rise on coastal flooding is amply demonstrated by comparing Hurricane Isabel of 2003 with another major storm: the hurricane of August 1933, widely regarded as the “storm of the century” for Hampton Roads. The 1933 hurricane was more powerful than Isabel and produced a storm surge (rise in water level due to the effects of the storm) of 1.8 m (5.8 feet) as compared to 1.5 m (4.8 feet) for Hurricane Isabel in Hampton Roads. Yet the maximum water level or storm tide (sum of the storm surge and the astronomical tide) for both storms was about the same: 2.4 m (8.0 feet) for the 1933 hurricane and 2.4 m (7.9 feet) for Isabel. The reason the weaker of the two storms produced an equivalent storm tide is that monthly mean sea level during Isabel stood about 0.43 m (1.4 feet) higher than the monthly mean during the August 1933 hurricane. Most of the difference is due to sea level rise during the 70 years between these two storms. -- emphasis added Hurricane Isabel was 'only' Cat 2 at landfall in North Carolina (south of the Hampton Roads, Virginia location discussed above); the Outer Banks storm of 1933 was Cat 3 at its first landfall in about the same location. Regarding Isabel's effects on Virginia alone: The hurricane caused about $1.85 billion (2003 USD, $2.17 billion 2008 USD) in damage and 36 deaths in the state — 10 directly from the storm's effects and 26 indirectly related. Too bad those folks just didn't adapt.
  12. Ocean Cooling Corrected, Again
    Rob Painting #58 and #62 You have nearly answered your own question at #62. BP was pointing out that three sea level equivalent measures were inconsistent with the oceans gaining heat. Land Ice melt was equal to a mass increase +3.1mm/yr, Satellite SLR was equal to +2.3mm/yr so therefore steric rise must be negative (-1.1mm/yr if isostatic rebound is included). Therefore these measurements do not support a rise in OHC. That does not mean that any measurement is gold plated. Argo might be right in measuring a 0.39W/sq.m OHC increase and the satellite SLR wrong of the ice melt estimate wrong. You at #61 are now supporting the point with references that in last interglacial the large mass rise from Antarctica occurred with a negligible steric rise. The conclusion from that is during in the last interglacial all the heat went into ice melt and little into warming the oceans. A feasible transport mechanism for the heat would be needed - however as BP pointed out if you can concentrate the heat into melting land ice - you only need 1/58th the amount to get a unit rise in sea level compared with thermally expanding the oceans. Over to you for the feasible transport mechanism.
  13. Rising Oceans - Too Late to Turn the Tide?
    Agnostic#52: "there us no effective defence against SLR which is continuous" The only defense I've heard continuously on this thread is a variant of 'I can't see it happening to me right now' aka 'it's not my problem'. A series of talks given at an SLR conference in the US last year are available here. These slide shows are well worth a browse. One author described the economic effects to the Galveston Bay area of 0.69m and 1.5m SLR -- when combined with a 100 year storm. That's exactly the scenario we've been labeling 'conservative;' the results will cripple the region's economy (which is already not doing too well). Another author stressed the need to begin making decisions now. That's not going to happen if the prevailing attitude is a hand-waving 'we can adapt.' But the east bank of New Orleans is resting easier behind what they are calling a 100 year floodwall; claims by the Army Corps of Engineers (who designed it - as well as the prior failed levees/canal system) are that they included both SLR and subsidence potential in their calculations. So with enough money, concrete and 6 years of hard work, it seems possible to defend one location. Unfortunately for the surrounding area, doesn't a wall in one spot just mean more flooding someplace else?
  14. More Carbon Dioxide is not necessarily good for plants.
    I stumbled onto some very troubling information recently which indicates that (on average) the optimum temperature for photosynthesis in C3 plants is 76F (24.4C) and that a 10% drop in photosynthesis occurs for every degree F until 86 F (30C) is reached. At this point the stoma are 100% closed to prevent water loss. This means that the CO2 argument "high CO2 is good for plants" is false since higher CO2 levels will produce higher temperatures thus lowering agricultural productivity. The results of my Internet-based research (if you can call it research) can be viewed here: http://www3.sympatico.ca/n.rieck/docs/world_population_limit.html I am now very worried that "climate change" combined with "the human population very close to 7 billion" places human culture in very grave danger. When food becomes less available, immune systems will become compromised resulting in pandemics of greater amplitude and frequency. Neil Rieck Kitchener / Waterloo / Cambridge, Ontario, Canada.
  15. The Ridley Riddle Part One: The Red Queen
    Perhaps the most interesting/concerning thing is the manner that otherwise smart people are willing to view science through ideological blinkers in support of extreme political views - this applies in spades to those of a libertarian bent. A shame considering that his book "Genome" is IMHO one of the best bits of popular science writing of recent times. I suppose the apparent disconnect between excellent writing of Genome and his dreary and "self-debunked" laissez-faire views that seem to underlie his misrepresentation of climate science, results from the former (description and impacts of genomic discoveries) being both broadly politically-neutral, and amenable to the rather reductionist/dissectionist approach he uses so well....whereas the latter (understanding and honest description of climate science) requires a rather broader and dispassionate approach which is simply incompatible with his politics. Incidentally I'm not familiar enough with Ridley's political views to know whether he considers publically funded science (which forms the mainstay of the research described in "Genome") to be part of the "parasitic bureacracy"....any pointers on that issue form his writing?
  16. Rob Painting at 20:39 PM on 31 July 2011
    Ocean Cooling Corrected, Again
    Sea level budget over the 2005-2010 period (half of 2010 anyway): Black line is the sea level as observed by satellite altimetry, blue line is the steric (expansion due to warming), red is the ocean mass according to GRACE gravity satellites, and purple is the steric and mass combined. So a reasonable match considering the uncertainty in the datasets. Note the steric component tailing off. See: Balancing the Sea Level Budget - Leuliette & Willis (2011) There's a whole bunch of recent discussion papers at the Oceanographic Society magazine in the link above - for any interested readers.
  17. Rob Painting at 19:57 PM on 31 July 2011
    Ocean Cooling Corrected, Again
    Albatross - I never expect to convince a faux skeptic, but genuine skeptics can't help but be convinced that global warming is real, it's happening now, and will be a huuuuge problem. But BP does raise an extremely worrying point, one I only hinted at in the post. The thermal component of sea level rise does appear to have slowed in the last decade. Yes, I know short datasets and large uncertainty and all that, but it seems to be the case. Sea level rise on the other hand continues to rise, confirming the accelerated melt observed on the Greenland and West Antarctic icesheets i.e. ice melt has made up a larger proportion of the sea level rise in the 'noughties'. So why is it worrying?. See the paper referenced in this post: Rising Oceans - Too Late to Turn the Tide?. The Role of Ocean Thermal Expansion in Last Interglacial Sea Level Rise - McKay (2011) I'll cut to the chase: "Taken together, the model and paleoceanographic data imply a minimal contribution of ocean thermal expansion to LIG sea level rise above present day. Uncertainty remains, but it seems unlikely that thermosteric sea level rise exceeded 0.4±0.3 m during the LIG. This constraint, along with estimates of the sea level contributions from the Greenland Ice Sheet, glaciers and ice caps, implies that 4.1 to 5.8 m of sea level rise during the Last Interglacial period was derived from the Antarctic Ice Sheet. These results reemphasize the concern that both the Antarctic and Greenland Ice Sheets may be more sensitive to temperature than widely thought." And note this recent paper on the Greenland icesheet: Sr-Nd-Pb Isotope Evidence for Ice-Sheet Presence on Southern Greenland During the Last Interglacial - Colville (2011) "These results allow the evaluation of a suite of GIS models and are consistent with a GIS contribution of 1.6 to 2.2 meters to the ≥4-meter LIG sea-level highstand, requiring a significant sea-level contribution from the Antarctic Ice Sheet." You'll note a great deal of coherency between the papers I'm referencing -the observations seem to fit. The last paper is more worrisome, even in the last interglacial, when the Northern Hemisphere summer saw the brunt of the warming, most of the melt contributing to SLR came from Antarctica.
  18. The Ridley Riddle Part One: The Red Queen
    So many errors, so little interest in addressing them all... First, Ridley accepts the premise economics is scientific and ignores that it is practically useless due to not accepting the role of resources. I refer him to Steve Keen as one of the few economists who appears to be sane. Second, Ridley essentially accepts people are generous while ignoring over 80 years of intentional conditioning to spend and consume. Third, he ignores that we have also raised the individual above the group for centuries and conned ourselves into believing thus it has always been and thus must it always be. This, of course, ignores that the only sustainable cultures are aboriginal, group-centered, non-consumptive, based entirely on what the ecosystem can provide with a little assistance, and are rooted in shared experience. The simplest rebuttal of Ridley on these scores is the lowest tax rates, least regulation and greatest profits in our history have resulted in the beginning of the end of this era. As for climate, seriously, if he is so illiterate in science that a 40% reduction in plankton is a conspiracy, can anyone take him seriously? And the pejorative turns of phrase regarding issues of common sense identifies him as an ideology-driven man. He is a shining example of the phenomenon described in "The Authoritarians." And when crop reductions of 3% are already being realized due to climate stressors, can we not laugh at his failure to understand the law of the Minimum? For all his education and - I'll take your word for it - brilliance, to cite a single component of extremely complex systems (billions of biota in a handful of soil, e.g.) as something that will save us all is rather embarrassing for him. I don't think this guy is a systems thinker. Well, that's enough. More where that came from, though.
  19. Ocean Cooling Corrected, Again
    Rob @58, It is unfortunate that Ken cannot see the absurdity of BP's claim that I quoted above. If people wish to see a correct accounting of the terms in Question then please read Hansen et al. (2011) that Sidd linked to above @54. It is a long document but I highly recommend that people interested in this issue read the paper-- it is an excellent investment of one's time. SteveS @56, Thanks, very interesting. You will most likely not convince BP or Ken though, they will most likely just brush it off or glibly dismiss it.
  20. An experiment into science blogging
    Is it kosher to draw attention to this, BTW? Or should it just be left to those who'd find it in the ordinary course of things?
  21. An experiment into science blogging
    You don't have a scriptblocker running by any chance, lukeness? Because I counted 12 comments! I figure you'd have to at least allow SkepticalScience itself and perhaps googleapis, judging from a quick check of my own NoScript list for this site.
  22. Rising Oceans - Too Late to Turn the Tide?
    Pirate - just to be clearer, supposing you are wrong - sealevel rise causes significant costs for adaptation - do you accept the principle that your country should be taking responsibility for your countries share of the emissions that caused the problem? This is a question of principle not science - that of assuming responsibility for actions.
  23. An experiment into science blogging
    It seems to me that the questions regarding comments weren't meaningful, since I couldn't see any comments when I read the post.
  24. Rising Oceans - Too Late to Turn the Tide?
    Muoncounter Your assessment of the effects of SLR are spot-on, particularly the certainty that they will cause flooding of low coastal land and river deltas – often among the more heavily populated areas of the planet and certainly among the major food producing areas. The effects on a global population of 10 billion, of whom 7 billion now live in such areas, is not difficult to imagine. What intrigues me is that so many commentators assume that the rate of SLR is either static or linear. It can be neither. SLR is primarily caused by loss of land based snow and ice, particularly polar ice. Even a casual glance at polar ice mass loss data should be sufficient to show that the rate of loss is non-linear, increasing and expected to go on increasing for the rest of this century. Consequently SLR will continue to increase and do so at an increasing rate this century and for centuries to come. The question is how much will it rise by 2100? The answer varies from 1-5m depending on which authority you listen to. What is clear is that even a conservative estimate of 1m SLR by 2100 has the potential to be tremendously damaging since there us no effective defence against SLR which is continuous – and it is certainly not going to stop in 2100.
  25. Rising Oceans - Too Late to Turn the Tide?
    Pirate, it's not hard to make an assessment for what 50-80cm of sealevel rise will do locally. Since is low-end of expectation, I take it you arent actually in denial that this will happen? It's real easy to ignore sealevel effects if your position is that it is not happening. This was subject of public meeting for our city who are already battling a number issues (coastal erosion, salt water excursion in low lying farmland and rising water table in southern suburbs). 50-80cm is no cause for panic but it is a considerable cost to the city and complicated because you have to solve a number of problems all at the same time. Who's paying? Making pious statements about problems of people living on unstable areas is pure diversion. We are only talking about EXTRA pressure created by sealevel rise. This in addition to existing problems. Fertile deltas are always going to be heavily populated. Now lets look at how much displacement from say 80cm of rise, divide by 100 years and work out the required immigration per year. Is your country prepared to take to avoid that conflict?
  26. Monckton at odds with the very scientists he cites
    I've just been reviewing the Monckon Myths page and noticed that this article does not seem to be linked to it yet (even though the later-arriving article on the debate with Denniss has).
  27. Ocean Cooling Corrected, Again
    A thing that may be useful to show: Sea level rise (detrended) vs. Multivariate ENSO Index From the University of Colorado article: "To compare the global mean sea level to the MEI time series, we removed the mean, linear trend, and seasonal signals from the 60-day smoothed global mean sea level estimates and normalized each time series by its standard deviation. The normalized values plotted above show a strong correlation between the global mean sea level and the MEI, with the global mean sea level often lagging changes in the MEI. Since the MEI has recently sharply increased (coming out of a strong La Niña), we expect the global mean sea level estimates to also reverse their recent downward trend and begin to increase as the La Niña effects wane." In the next months sea level should go up as the global ocean responds to the end of La Niña. We have just to wait and see.
  28. Rising Oceans - Too Late to Turn the Tide?
    pirate#47: "There you go." Overpopulation is neither the issue nor the topic here; sea level rise is. What, specifically, are the adaptations that you forecast? Hopefully you have more up your sleeve than either moving inland or building floodwalls.
  29. Bob Lacatena at 09:44 AM on 31 July 2011
    Rising Oceans - Too Late to Turn the Tide?
    48, apiratelooksat50, The point isn't whether any one ecosystem is threatened right now. The point is that there are certainly ecosystems that will be threatened by a 3 mm/yr rise in sea level, if it continues for any length of time, and even more (and sooner) if it accelerates. Hansen makes a decent case for that being a possibility that should be considered, even if any might consider it unlikely.
  30. Earth's Climate History: Implications for Tomorrow
    @pirate #31: Your qualifier, "within reason" does indeed merit further discussion.
  31. Monckton Myth #17: Debate vs. Denniss, Part 2
    In a recent press release, Lord Monckton claimed:- * "Forestalling all of the 0.24 C° global warming predicted by 2020 would demand almost $60,000 from every man, woman and child on the planet. * That cost is equivalent to almost 60% of global GDP to 2020. He repeated these figures at his National Press Club debate. Treasury modelling states that the carbon tax will reduce Australian GDP by 0.3% in 2020 ($171 per head per annum)and reduce our CO2 equivalent emissions by 25% over business as usual. Why should a global solution cost 60% of GDP? Not surprisingly, Monckton employs a number of "tricks" to exaggerate the cost of a climate change solution. Firstly he calculates the cost of implementing a solution with NO manmade CO2 emissions. This raises the cost to 0.3%*4 =1.2% of GDP. Next he uses the reduction from 2000 levels (5%) instead of the reduction from business as usual 2020 levels(25%). That multiplies the result by another factor of 5 to get to 6% of GDP. This is still not large enough, so Monckton calculates the gross value of the tax rather than the impact on GDP. Even when calculating the gross value of the scheme, he adds both the tax received and the expenditures from the tax (such as administration, renewable energy support and coal and steel support). By this means, Monckton estimates the net cost of the current scheme as $13 billion per annum or 1% of GDP instead of Treasury's figure of 0.3% This calculation brings Monckton's calculation of the global abatement cost up to 20% of GDP but Monckton has a few more "tricks" up his sleeve. Monckton assumes that the carbon pollution measures only the impact of CO2 - 51% of manmade forcings. He therefore doubles the cost again to allow for eliminating all the other manmade forcings such as methane - bringing us up to 40% of GDP. Of course the Australian carbon tax does tax methane emissions ( as the coal industry will attest to ). Monckton understands that Australia has 2% of global GDP but contributes only 1.2% of global CO2 because we have high energy efficiency. He therefore implicitly assumes that the cost of abatement in countries with low energy efficiency would be the same as Australia's. Multiplying 40% by 2%/1.2% brings Monckton up to his 60% of GDP. Just in case all the tricks haven't been enough to scare the public, Monckton has one last card to play. He calculates the cost per head over a 10 yesr period rather than a cost per year. The cost per head becomes $59,000 instead of $5,900 per head per annum. The bottom line is that Australia will reduce its emissions by 25% over business as usual levels at a cost of 0.3% of GDP per annum or $172 per head per annum. I could only conclude that Lord Monckton deliberately set out to deceive his audiences with a patently ridiculous cost for tackling climate change.
  32. Rob Painting at 08:23 AM on 31 July 2011
    Ocean Cooling Corrected, Again
    KL - "Why would you use the term 'ludicrous'? I checked the numbers BP offered up in support of his argument and they are correct." That's curious Ken, for the best part of 18 months at least you have been proclaiming the ARGO dataset as the best measure of ocean heat content (it is - but still has issues to be resolved), but now it is clear that the oceans are still warming, albeit at a slower rate than the 1990's, the ARGO floats are now worthless?, because of BP's erroneous assertions? That's one big flip-flop.
  33. apiratelooksat50 at 08:19 AM on 31 July 2011
    Rising Oceans - Too Late to Turn the Tide?
    Sphaerica @ 45 Respectfully, can you list the ecosystems in trouble so I can reply?
  34. apiratelooksat50 at 08:18 AM on 31 July 2011
    Rising Oceans - Too Late to Turn the Tide?
    Muon @ 46 Let me amend my statement based on your version of my statement. "We can and we must adapt to possible changes in sea level." Both of the references you noted may become real, but it is absolutely not going to happen overnight. It will take decades. These people in the developing world really don't have much to move. As a matter of fact, they've been moving back and forth with shifting land masses ever since the regions were settled. I guess it is hard to feel sorry for an affluent person on Pawleys Island, SC who loses their million dollar vacation home due to shifting sands compared to the millions you reference in your links. I know I don't feel sorry for anyone who builds expensive structures in areas prone to hurricanes, flooding, earthquakes, or landslides. I bet you don't either. Overpopulation is a real issue in developing countries especially when compared to developed countries. If they choose to live in unstable areas, then I'm not sure what can be done about that. There you go. What is your solution?
  35. Rob Painting at 07:59 AM on 31 July 2011
    Ocean Cooling Corrected, Again
    KL -"This is what Dr Trenberth** said on SKS about the 'Asian sulphates' explanation for the stasis in surface temperatures:........ I know Doc Trenberth disagrees but the paper I linked to @45 doesn't agree with the 0.9w/m2 value often quoted. Furthermore the paper cited (Hatzianastassiou (2011) in Dana's recent post Michaels Mischief #1: Continued Warming and Aerosols shows a pronounced 'global dimming', particularly the southern hemisphere during the 'noughties '. Just saying you shouldn't get hung up on the 0.9w/m2 figure, be a genuine skeptic on that number.
  36. Ocean Cooling Corrected, Again
    Albatross @51: "There is the (possible) mechanism required for the increase in deep ocean heat content that the "skeptics" keep whining about. " This isn't anything I'm really an expert on, but I do note that there are (at least) two observed mechanism known to allow heat from the surface to interact with the ocean floor (and vice versa): 1. Interannual atmospheric variability forced by the deep equatorial Atlantic Ocean, also discussed here 2. Surface-Generated Mesoscale Eddies Transport Deep-Sea Products from Hydrothermal Vents, also discussed here I don't think heat transport was a main interest in either study, so that information might not be available (so far, I've only found the abstracts). But at least the second paper implies Reynold's numbers high enough to provide for mixing. The discussion of the second also implies that there hasn't been much research into the interaction between the ocean surface and ocean floor, so who knows what will be found if/when people start looking. But they provide decent known mechanisms for ocean surface/floor interactions.
  37. Ocean Cooling Corrected, Again
    Hello Ken, I'll respond to your post @52 as soon as I can find a suitable window of time. For now, I will note that your post is a great example of the blind spot that you have for BP's musings, and I'll note too that BP has still not responded to requests to provide a reputable scientific citation that refutes von Shuckmann and Le Traon (2011). Also, I would ask for you to please elaborate on what the implications of this perceived "fundamental inconsistency in the AGW science" are. Are you trying to suggest that the theory of AGW has been overturned? Are you suggesting that it means that climate sensitivity to doubling CO2 is grossly overestimated? Thanks.
  38. Rising Oceans - Too Late to Turn the Tide?
    pirate#44: "That is certainly adaptable by plants, animals, and human animals." In order to adapt, one must first be aware of the problem. In the case of humans, comments like this are among those that will keep lots of people in the dark. "On the Waccamaw River in coastal SC, ..." Your examples reveal nothing more than confirmation bias. Do you not understand that it is the combination of subsidence due to poor coastal land management and the effects of rising sea level (plus increased storm surge) that are the problems? Or that the point of this article was 3mm/yr measurable now, more to come fairly soon? There is a host of literature detailing the risks of sea level rise; example Dasgupta et al 2007: Sea-level rise (SLR) due to climate change is a serious global threat: The scientific evidence is now overwhelming. Continued growth of greenhouse gas emissions and associated global warming could well promote SLR of 1 m in this century, and unexpectedly rapid breakup of the Greenland and West Antarctic ice sheets might produce a 3–5 m SLR. ... Our results reveal that tens of millions of people in the developing world are likely to be displaced by SLR within this century; and accompanying economic and ecological damage will be severe for many. At the country level results are extremely skewed, with severe impacts limited to a relatively small number of countries. Another is Nicholls et al 2008: This paper explores for the first time the global impacts of extreme sea-level rise, triggered by a hypothetical collapse of the West Antarctic Ice Sheet (WAIS). As the potential contributions remain uncertain, a wide range of scenarios are explored: WAIS contributions to sea-level rise of between 0.5 and 5 m/century. Together with other business-as-usual sea-level contributions, in the worst case this gives an approximately 6-m rise of global-mean sea level from 2030 to 2130. Global exposure to extreme sea-level rise is significant: it is estimated that roughly 400 million people (or about 8% of global population) are threatened by a 5-m rise in sea level, just based on 1995 data. -- both emphases added Yet all you can offer is 'we can adapt'.
  39. Bob Lacatena at 02:47 AM on 31 July 2011
    Rising Oceans - Too Late to Turn the Tide?
    44, apiratelooksat50,
    A change from 0.5 mm/yr to 3.0 mm/yr may appear to be drastic, but let's look at it realistically.
    You are ignoring the "per year" aspect of a 2.5mm/yr increase. Ten years, 25 mm. Fifty years, 125 mm. Beyond this, storm surges and other factors make periodic maximums even larger. Also, sea level changes are not homogeneous. This is a global average, but individual changes can be much, much greater, due to regional effects. Places like the Netherlands and New Orleans are also already dangerously below sea level. Meanwhile, for many ecosystems parts of the world, even this seemingly small change is large. Your provision anecdotal examples of cases where changes are not relevant says nothing about the frequency or importance of cases where it is.
    Moderator Response: [mc] fixed closing blockquote tag
  40. Ocean Cooling Corrected, Again
    To follow up to my own post: The hansen energy imbalance paper provides various estimates of contributions to heat uptake http://www.columbia.edu/~jeh1/mailings/2011/20110415_EnergyImbalancePaper.pdf sidd
  41. apiratelooksat50 at 01:48 AM on 31 July 2011
    Rising Oceans - Too Late to Turn the Tide?
    Muoncounter @ 40 A change from 0.5 mm/yr to 3.0 mm/yr may appear to be drastic, but let's look at it realistically. Pull the plug out of your iPod earbuds. The width of that plug is roughly 0.12 inches = 3 mm. That is certainly adaptable by plants, animals, and human animals. Coastal marshes can change annually from salt to brackish to fresh. So, your statement about saltwater intrusion destroying wetlands is only partially correct. You would need to read more than the abstract in the link provided. The interface between land and sea is dynamic and there is always a battle between the creation and destruction of land. On the Waccamaw River in coastal SC, where I used to live and still maintain a home, we witnessed a massive saltwater intrusion that killed freshwater species many miles upstream. The cause was an extended drought and not sea level rise. As the drought abated over the next few years, we witnessed a change back to the brackish and freshwater species. The smaller freshwater species recovered more quickly than the larger ones such as bald cypress. This is a nice powerpoint on a Delaware Estuary Study Also, anthropogenic pressures on tidally influenced freshwater streams and estuaries largely come from urbanization, improper land use practices, impervious cover, dredging and any change to the hydrology of the stream. One of the major problems in the loss of the Louisiana wetlands were the creation of dams, levees and canals which increased the rate of water flow and did not allow the usual sedimentation to occur. From Louisiana State University "During the last few decades, the human factor in wetland loss has increased drastically. The placement of dams and levees across and along the tributaries and distributaries of the Mississippi River have reduced both the amount and texture of sediment reaching the coast." [inflamatory snipped]
    Moderator Response: [Dikran Marsupial] Please stick to the science and leave the moderation to the moderators.
  42. Ocean Cooling Corrected, Again
    Is there an estimate with error bars of continental heat uptake ? I have seen estimates of 0.75x10^22 J but with no error bars Thanx sidd
  43. Michaels Mischief #1: Continued Warming and Aerosols
    Thanks again, Sphaerica @87; I've linked to your summary at the Bad Astronomy thread.
  44. Bob Lacatena at 00:47 AM on 31 July 2011
    Michaels Mischief #1: Continued Warming and Aerosols
    85, Composer99, A quick summary of RC's key points:
    • Not all satellite datasets give the same extreme result... they chose the one that makes their claim look best
    • The paper lacks the supporting statistical information to make it credible
    • The paper lacks the information to make it repeatable
    • Those two items alone demonstrate very shoddy peer review
    • The journal it was published in is in no way a credible climate science or atmospheric physics journal
    • RC's own similar analysis shows different results (and these are clearly provided by them)
    • The overly simplistic model is one that Spencer has used before and has already been proven to be grossly flawed and easily manipulated to produce any desired result, and so is wholly improper in its use in this context
    • Like Lindzen before them, in order to use such a small time frame, Spencer uses ENSO warming as a proxy for climate change without accounting for the fact that ENSO is very different from actual climate change, and is not a forcing itself
    • Their conclusions about climate sensitivity are incorrect and unsupportable
  45. Bob Lacatena at 00:39 AM on 31 July 2011
    Michaels Mischief #1: Continued Warming and Aerosols
    85, Composer99, The RC post is pretty specific, and pretty scathing. They apparently agree with my assessment that their conclusions about climate sensitivity are invalid, and also find numerous flaws in the methodology, and do a pretty darn good job of backing up that claim. What's their bottom line?
    The bottom line is that there is NO merit whatsoever in this paper. It turns out that Spencer and Braswell have an almost perfect title for their paper: “the misdiagnosis of surface temperature feedbacks from variations in the Earth’s Radiant Energy Balance” (leaving out the “On”).
  46. Michaels Mischief #1: Continued Warming and Aerosols
    Thanks, Sphaerica.
  47. Bob Lacatena at 00:11 AM on 31 July 2011
    Michaels Mischief #1: Continued Warming and Aerosols
    80, Composer99, An oft repeated quote in the blog entries I've found (I'll trust Trenberth over Spencer any day of the week, year, decade or century):
    "I cannot believe it got published," said Kevin Trenberth, a senior scientist at the National Center for Atmospheric Research.
  48. Bob Lacatena at 23:58 PM on 30 July 2011
    Michaels Mischief #1: Continued Warming and Aerosols
    80, Composer99, RealClimage did just yesterday do something with this here. And the blog post I just linked to also has this analysis.
  49. Bob Lacatena at 23:55 PM on 30 July 2011
    Michaels Mischief #1: Continued Warming and Aerosols
    80, Composer99, A quick google search did find this: No, new data does not “blow a gaping hole in global warming alarmism”
  50. Bob Lacatena at 23:52 PM on 30 July 2011
    Michaels Mischief #1: Continued Warming and Aerosols
    80, Composer99, It was only just published days ago, so I'm sure it will take a while for even serious blog criticisms, let alone rebuttals, although except for reputation and past performance, there's no reason on the surface to believe what the paper says is entirely wrong. I'm only just reading it right now, but an early assessment based on the conclusions, from a purely amateur point of view, is that I don't believe these findings in any way affect climate sensitivity. They may affect the rate of warming due to the rise in CO2, and so arriving at the final temperature setting for the level of CO2 we pump into the atmosphere may take longer. That would, in fact, be somewhat in keeping with what we are observing. It would also be dangerous, because it could lead to a false sense of security that climate sensitivity is low. That would cause us to burn more fossil fuels, and raise CO2 levels even higher, when that end result could be totally untenable for the poor souls that have to live in those conditions long after we're gone. And they'll have to find a way to combat those conditions without any fossil fuels as even a minor factor in the battle, because by then they'll be all gone, or the atmosphere will be so badly polluted with CO2 that they won't dare to add a single additional ppm. But simply because the planet is able to shed heat more quickly, to me, does not imply low climate sensitivity, but rather only a slower rate of warming. The final temperature will be the same. So while the paper's results may be correct, I'm not entirely sure that the conclusions they make properly follow those observations. But, as I said, I haven't yet read the full paper, and I don't think the people who are truly qualified to do so will be able to get to it for some time yet.

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