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Comments 116701 to 116750:
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Doug Bostrom at 02:20 AM on 26 June 2010Ocean acidification
Stop whining about C02 Is it an insurmountable intellectual challenge to realize that we're capable of causing more than one problem simultaneously and that different problems may act on different time scales? Please, you can do better. -
dhogaza at 02:19 AM on 26 June 2010September 2010 Arctic Ice Extent Handicapping Via ARCUS
"Currently the arctic is (and has been for a month) at its record low in extent. If going toward the pole the ice is thicker than that found last summer it may slow down a bit. But if the increased thickness is due to ridging it may not happen, it cracks and melts more easily." The thing I find interesting is that the cryosphere ice area calculation is dropping like a rock. It took a real step turn downwards a couple of weeks ago, while the extent estimates continue on roughly a linear pace. There are problems with melt ponds on top of the ice fooling the various ice measurement algorithms, but year-to-year comparisons should still be apple-to-apple. So it appears that not only is extent dropping rapidly, but there's more open water within the extent area compared to the last couple of years, due to recent acceleration of the decrease in area mentioned above. I still think 2008 < 2010 < 2009 but am prepared to be surprised on the low end. It's going to be a good summer to watch ice. -
Chris G at 02:10 AM on 26 June 2010How many climate scientists are climate skeptics?
I would have been interested in seeing the charts above with an added dimension of time. The reason I say that is because I get the impression that the deniers believe that the anti-AGW researchers are like a voice in the wilderness that will eventually be proven correct. It appears to me that, about 100 years ago, AGW proponents were the voice in the wilderness. Over time, and much research, their position has grown in strength. In that light, the anti-AGW proponents are more like the last holdouts rather than leading edge drivers of a new paradigm. -
Philippe Chantreau at 02:01 AM on 26 June 2010How Jo Nova doesn't get the CO2 lag
Arkadiusz, is there such a thing as "official scientific reviewer" in IPCC terminology? I remember the term "expert reviewer", a status in fact so open that it does not mean much. Are you talking about the same thing? We already had that conversation about Dip Phil Courtney, who is just a PR guy by trade. Full information indeed is necessary, as in the Maxwell Bay sediment core story. The expert review invitation thingy was discussed long ago here: http://rabett.blogspot.com/2008/02/on-astounding-diplphil-courtney.html -
Riccardo at 01:42 AM on 26 June 2010September 2010 Arctic Ice Extent Handicapping Via ARCUS
There will always be more multi-year ice when last summer did not melt as much as the second last. This is trivial. To have volume you have to combine thickness and ice extent or area. Trivial, again. Currently the arctic is (and has been for a month) at its record low in extent. If going toward the pole the ice is thicker than that found last summer it may slow down a bit. But if the increased thickness is due to ridging it may not happen, it cracks and melts more easily. I will not bet on next september minimum, too complicated to put a reasoned one. Considering the standard deviation of 0.5 MKm2 calculated from NSIDC data, I don't see much of a difference between the various estimates. But one thing seems likely, the lack of recovery after 2007 (as a trend, not a few years) will be confirmed. -
Philippe Chantreau at 01:32 AM on 26 June 2010How many climate scientists are climate skeptics?
This is so funny. On one hand we have Watts and Goddard doing grotesquely inept maths with percentages so that they can claim "Western snow pack is 137% of normal." And the Hoi Polloi crowd goes wild: "I've had so much snow this winter." Skepticism nowhere to be found. On the other hand we have the Anderegg survey and statements like this in Slate: "perception that climate activists will credulously push any news that might further their case." The double standard has gone so far, it's downright ludicrous. But no "skeptic" protest is to be heard. Skeptics by name only, a name they actively empty of all the substance it used to have. -
CBW at 01:27 AM on 26 June 2010September 2010 Arctic Ice Extent Handicapping Via ARCUS
HR: "I also predict that PIOMAS will underestimate again this year." Note that the Zhang prediction isn't entirely based on PIOMAS. Here is a link to the prediction page: http://psc.apl.washington.edu/zhang/IDAO/seasonal_outlook.html Also, Ron Lindsay (also at PSC) has his own prediction method: http://psc.apl.washington.edu/lindsay/September_ice_extent.html I find all of these predictions interesting, but not particularly helpful to the discussion of AGW because they distract from the data. The long-term trend is what is important. The predictions, while they serve a useful purpose for regional economic and environmental activities, give critics ammunition when they are wrong, as they often will be in an area with weather systems that are as variable as those of the arctic. The data alone make the case well enough. The long-term trends of arctic sea ice extent, area, and volume are downward, and that is very strong evidence of a warming arctic climate. -
Philippe Chantreau at 01:15 AM on 26 June 2010September 2010 Arctic Ice Extent Handicapping Via ARCUS
I wouldn't venture to any prognostic myself. Arctic sea ice is very weather dependent from year to year. Right now it is rather low and the decline since the max extent has been quite steep. But the summer decline is dependent on wind patterns perhaps more than anything else. If winds do not disperse the ice, it won't be carried away and melt. Prognostic is much of a gamble. All we can do is wait and see -
snapple at 01:15 AM on 26 June 2010September 2010 Arctic Ice Extent Handicapping Via ARCUS
Some of those denialists spin more than a baby seal being tossed by an orca! http://legendofpineridge.blogspot.com/2010/06/george-monbiot-attacks-delingpole-spins.html -
dhogaza at 01:09 AM on 26 June 2010September 2010 Arctic Ice Extent Handicapping Via ARCUS
"Given that the ice sheet extent is on track to dip below the record low Sept/Oct 2007 levels that caused panic at the IPCC, you folks are showing admirable restraint. Nobody is going ape s**t." IPCC suggests that the arctic will become ice free in summers in the 2050-2100 time frame, hardly panic. If you want panic, note that those noted warmists Watts and Goddard recently predicted an ice free arctic by 2060. Much more pessimistic than the IPCC! Of course there's been a flurry of posts afterwards trying to live that down, since they were apparently under the misapprehension that the consensus date for an ice free arctic is 2013... -
Peter Hogarth at 23:28 PM on 25 June 2010Is the long-term trend in CO2 caused by warming of the oceans?
Lon Hocker at 17:37 PM on 24 June, 2010 Thank you for commenting here, and the effort at reasoned discussion. I’m late to this conversation, and just posted these images on another thread on “acidification”. They are pertinent to this one also, so I hope all will forgive the repetition.
This image is from here which shows gridded annual average air/sea carbon flux.
By measurement and best estimates the ocean is a net CO2 sink and is changing pH most rapidly in areas of highest uptake. If we accept what NOAA and other Oceanographic Institutes etc are telling us, then your premise is suspect without invoking any maths. How can you account for a trend of more measured CO2 in the ocean over time (and with overall warming in the same period), rather than less?
The ocean is absorbing a large proportion of the extra emitted anthropogenic CO2, which also explains the difference between increasing measured atmospheric concentration and estimated anthropogenic output, ie the extra emissions not residing in the atmosphere are going somewhere (split between Ocean and other sinks such as increased vegetative biomass in NH). These strands of evidence are consistent.
From R. Feely, Pacific Marine Environmental Laboratory, NOAA, with atmospheric data from Pieter Tans and seawater data from David Karl. Adapted from Feely (2008) in Levinson and Lawrimore (eds), Bull. Am. Meteorol. Soc, 89(7): S58.
Enough instrumental evidence has now accumulated so that this trend in overall pCO2 increase and reduction in alkalinity is now accepted as measured fact rather than possible emerging trend, model or theory. As such, your proposed mechanism needs revision. However the correlation between temperature and CO2 derivatives is interesting, and would go some way to explain the variations superimposed on the rising trend. To counter this however, I would suggest you check Southern Hemisphere CO2 seasonal variations (relatively much more Ocean), which are considerably less than NH variations (relatively more land). Just a thought.
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VoxRat at 23:17 PM on 25 June 2010Ocean acidification
"THESE WARM SEA’S CHARACTERIZED MOST DIVERSE AND VARIED LIFE IN OCEANS AS WE KNOW." I don't think anyone is suggesting that dropping the pH a few tenths of a point - even a full point or two - or raising the temperature a degree or two or five is incompatible with life, which seems to be the strawman argument you're addressing. Try this thought experiment: change the temperature in the Red Sea to that of the mid-Pacific. What happens to the that "MOST DIVERSE AND VARIED LIFE"? Now change the pH to that of the mid-Pacific. What happens? Now, change both of them, and not over the tens or hundreds of thousands of years that (I'm guessing) the Red Sea biome had to adapt to the current conditions, but in the course of a century or two. What happens? -
Arkadiusz Semczyszak at 23:16 PM on 25 June 2010Ocean acidification
“A team of scientists from the New York-based Wildlife Conservation Society (WCS) has reported a rapid recovery of coral reefs in areas of Indonesia, following the tsunami that devastated coastal regions throughout the Indian Ocean four years ago today. The team, which has surveyed the region's coral reefs since the December 26, 2004 tsunami, looked at 60 sites along 800 kilometers (497 miles) of coastline in Aceh, Indonesia. The researchers attribute the recovery to natural colonization by resilient coral species, along with the reduction of destructive fishing practices by local communities. While initial surveys immediately following the tsunami showed patchy (albeit devastating) damage to coral reefs in the region, surveys in 2005 indicated that many of the dead reefs in the study area had actually succumbed long ago to destructive fishing practices such as the use of dynamite and cyanide to catch fish. [...] It is also possible that the crown of thorns starfish—a marine predator—had caused widespread coral mortality.” -
Arkadiusz Semczyszak at 22:41 PM on 25 June 2010Ocean acidification
Arabian Sea - with a pH of one of the lowest in the world (less than 7.95) ... In my youth, the first textbook about the life of the sea was, of course, "Sea Life" (Demel, 1974) Professor Demel, the eminent scientist (already dead), a member of many international scientific societies ... Recently, after many years, I found this book. Today I found there the following passages: "The Red Sea is a sea of the world's hottest maximum temperature in summer on the surface to 30oC, with "slots" extremely hot waters with temperatures exceeding 50 ° C and at depths to 2000 meters, not falling below 21.5 ° C ...", they has: "many strange sponge and very rich [...] coral reefs." and: "Persian Gulf, plate, lying on the shelf, the highest in the sea water temperature (up to 36 deg. C) is a place in the richest fishing mollusc (Pteriidae) of global world... " Professor ends like this: "THESE WARM SEA’S CHARACTERIZED MOST DIVERSE AND VARIED LIFE IN OCEANS AS WE KNOW." -
CBDunkerson at 21:35 PM on 25 June 2010Is the long-term trend in CO2 caused by warming of the oceans?
Lon Hocker #116: "CBDunkerson: Thank you for your strangely illogical comment. I found it amusing. As with e, I see little hope in helping you. Doug: Stop picking on e and CBDunkerson!" Ah. Trolling. Ok, you've officially passed the point of being worth bothering with. -
CBDunkerson at 21:27 PM on 25 June 2010September 2010 Arctic Ice Extent Handicapping Via ARCUS
BP #14/30, why would the yellow spot forming in the Beaufort be indicative of HIGH extent this year? Essentially what is happening is that a large area of thinner ice is being compressed into a smaller area of thicker ice by the gyre. Given that extent is 'ice area / concentration' wouldn't decreasing area and increasing concentration serve to yield a LOWER extent? That said, I expect the yellow swathe will break up as the season continues. That's the kind of pressed together 'rotten ice' they've been finding which doesn't really have much solidity to it. As to the general premise of the arctic basin ice being thicker this year than last - there has been alot of dispute about that with different methodologies coming up with different thickness measurements. However, I don't think it is as significant as you suggest... from the rate of decrease on the map it seems very likely that all the ice now at 2.5 meters in thickness or less is going to melt (indeed by the end of the animation the only such ice left is a small band that previously was 3+ meters thick). If you then look at the 3+ meter ice on the last frame of that 2010 map you'll see that it covers roughly a triangular shape "anchored across the northern edge of Greenland and Ellsmere Island and stretching northwards towards Severnaya Zemlya"... in other words, precisely the section I predicted would NOT melt this year. So yes, there is a core of potentially thicker / more solid ice (though some studies seem to indicate it is thinner/weaker than aerial observations suggest) in the Arctic basin this year. But if that is all which survives the melt, as seems very likely, then we're still looking at a very low extent this year. -
chris at 21:18 PM on 25 June 2010Ocean acidification
Berényi Péter at 21:07 PM on 25 June, 2010 Peter, you really need to read the Manzello paper whose abstract you linked to. The very fact that upwelling waters are [CO2] rich and thus relatively acidic means that coral reefs struggle in regions of upwelling. Manzello states this explicitly. In fact it's much of the point of his study, namely that as ocean acidification becomes widespread the degradative effects on coral reefs he observes in the eastern Pacific and around the Galapagos, will occur throughout the oceans. I just described this here with an excerpt from the Manzello paper -
Berényi Péter at 21:07 PM on 25 June 2010Ocean acidification
#38 Peter Hogarth at 18:32 PM on 25 June, 2010 "These naturally high-CO2 reefs persist near the Ωarag distributional threshold for coral reefs and are thus expected to be the first and most affected by ocean acidification" And how do you plan to prevent upwelling? BTW, damage to Galápagos reefs occurred during super El Niño events. When upwelling is suppressed, ocean pH goes up, and corals are starved to death. -
VoxRat at 21:05 PM on 25 June 2010Ocean acidification
Arkadiusz: ? No, it's not "acid". It's acidification: a drop in pH. -
chris at 21:02 PM on 25 June 2010Ocean acidification
Berényi Péter at 08:51 AM on 25 June, 2010 and Arkadiusz Semczyszak at 18:42 PM on 25 June, 2010 You guys are rather missing the point. VoxRat and Peter Hogarth have mentioned this but it's worth emphasising what the issues are. We can use the Manzello paper [*] that you (Peter) referred to as a guide: You (Peter) are doubly confusing (i) the nutrient content and (ii) [CO2] content (acidity) of cold upwelling waters in relation to (a) fishery productivity and (b) coral sustainability. These need to be seperated out properly: Upwelling cold waters have high [CO2] (and highish acidity), and high nutrient content. These (largely inorganic; e.g. nitrates and phosphates) nutrients are required for the photosynthetic plankton in the surface waters where sunlight penetrates. These phytoplankton use photosynthesis to convert [CO2] to biomass and this process is nutrient-limited. Therefore upwelling nutrient-rich cold waters promote phytoplankton growth and this stimulates bioproductivity higher up the food chain (lots of sardines to fish). The [CO2] levels and acidity of the waters are relatively unimportant for this except for those orgainsms that fix carbonate into their shells and skeletons. This is the problem in relation to acidification of the oceans. Corals are particularly sensitive to acidification, and not surprisingly the areas of upwelling of [CO2] rich waters is detrimental to coral growth. Manzello points this out specifically: He says (p. 245 of the paper Peter referred to):"Not surprisingly, reef development is scant in this highly marginal environment and ephemeral on geological timescales (Manzello 2009). Binding calcium carbonate cements do not precipitate[**] above trace levels in this low-Sigma(arag) environment and rates of bioerosion are the highest measured for any reef in the world (Manzello et al. 2008)."
[*] Manzello, D. P. (2010) Ocean acidification hotspots: Spatiotemporal dynamics of the seawater CO2 system of eastern Pacific coral reefs Limnol. Oceanogr., 55, 239–248 [*] i.e. the calcium carbonate "cement" that physically consolidates coral reefs, can't precipitate (it redissolves) as increased acidification drives down the concentration of dissolved carbonate, shifting the equilibrium between [carbonate(aq) ---- carbonate(precip)] in the direction of carbonate(aq). -
Arkadiusz Semczyszak at 20:59 PM on 25 June 2010Ocean acidification
... and whether such reconstructions: http://ioc3.unesco.org/oanet/OAimages/TurleypH.gif - are reliable and in general possible? -
Arkadiusz Semczyszak at 20:55 PM on 25 June 2010Ocean acidification
"acid" - it's of course acid?: "The Intergovernmental Panel on Climate Change's worst case scenario predicted that the pH of ocean waters could decrease to 7.85 by 2100." -
Peter Hogarth at 20:54 PM on 25 June 2010Ocean acidification
Arkadiusz Semczyszak at 18:31 PM on 25 June, 2010 and Berényi Péter at 08:51 AM on 25 June, 2010 We’re getting off topic. Concentrating on the global issue, I think the overarching concerns on anthropogenic CO2 (specifically) and reduced alkalinity of the Oceans can be summarized in the following images.
from here which shows gridded annual average air/sea carbon flux. The ocean is a net CO2 sink and is changing pH most rapidly in areas of highest uptake.
From R. Feely, Pacific Marine Environmental Laboratory, NOAA, with atmospheric data from Pieter Tans and seawater data from David Karl. Adapted from Feely (2008) in Levinson and Lawrimore (eds), Bull. Am. Meteorol. Soc, 89(7): S58. See also Sabines testimony and paper on this topic and Fabry 2008 where effects on the ocean ecosystem are discussed, and lack of detailed knowledge and need for more work is acknowledged, but:
“Nevertheless, sufficient information exists to state with certainty that deleterious impacts on some marine species are unavoidable, and that substantial alteration of marine ecosystems is likely over the next century”. I think this fairly reflects the view of most published ocean researchers in this field that I have read.
The current extremely high rate of increase in atmospheric CO2 is not something encountered in non-catastrophic “normal” geological history, and the trend should give cause for concern. We are correct to look at other factors and details also, but we should not miss the bigger picture. Why (if correct) is the balance of species changing?
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philipm at 20:46 PM on 25 June 2010How many climate scientists are climate skeptics?
#95 and #100: you may appreciate this article I wrote a while back, somewhat provocatively titled "When old men kill their children". -
Arkadiusz Semczyszak at 20:42 PM on 25 June 2010Ocean acidification
Just add by the “ship and tourists”: AIMS, 1997: “Firstly, the effects of the outbreaks have been confined largely to the central third of the Great Barrier Reef where the majority of tourist developments are located. Such effects may have severe ramifications for the local economy of Queensland and Australia in general.”, “In essence they revealed that the central third of the Great Barrier Reef (between Lizard Island and Townsville) had been affected by outbreaks within the previous 6 years. Within this region approximately 65% of all reefs surveyed were considered to have experienced a recent outbreak of starfish.” And where to from here is “the place” for “acid” - CO2? -
VoxRat at 20:30 PM on 25 June 2010Ocean acidification
Berenyi Peter: RE: pH Great! So now if we can just get the entire ocean to upwell, we can stop worrying that CO2-induced acidification is going to a problem. Though you did seem to miss thiz bit (that I meant to quote but Peter Hogarth did): "These naturally high-CO2 reefs persist near the Ωarag distributional threshold for coral reefs and are thus expected to be the first and most affected by ocean acidification" RE: pesticides "That's it" Pesticides are identified as a problem, therefore CO2/acidification is not? -
Berényi Péter at 20:02 PM on 25 June 2010Ocean acidification
The Independent Environment Great Barrier Reef polluted by pesticides By Kathy Marks in Sydney Thursday, 22 February 2007 "they show sediment creating a hazy cloud in the water over the reef, blocking out sunlight and preventing photosynthesis, the process which keeps coral alive" "sediment run-off carried pesticides washed off farmland" Well, stop whining about CO2.- use pesticides that decompose into harmless stuff in several weeks
- promote farming practices that limit soil erosion, the Right Thing to Do anyway
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Arkadiusz Semczyszak at 19:06 PM on 25 June 2010Ocean acidification
The increase in atmospheric pCO2 in the past 20 years, compared with 1.5 - 1.6% CO2 (free and chemically bonded) in the SS ocean ... Temperature - indeed the variability of El Nino - La Nina, the 90s, it was extremely violent - it is probably the most important here (does not "simply" temperature but its change - up - down). Anthropogenic pressures: period of 90 - those - that period of putting into service a significant number of large cruise ships, whose favorite "tour" is GBR. Direct damage to the GBR are not the most important fact here. Species, ecosystems individual reefs - atolls, it is often endemic. "Mixing species" - from bacteria to starfish ("The 2003 LTMP surveys showed that 15% of the surveyed reefs had outbreaks of crown-of-thorns starfish. This is higher than the number of reefs affected in the 1988 series, which resulted in widespread declines in coral cover on reefs in the central Great Barrier Reef ..." ) - is a disaster for most ecosystems GBR ... -
Arkadiusz Semczyszak at 18:42 PM on 25 June 2010Ocean acidification
4. “Carbon dioxide has been high in the past year coral reefs have continued to lay down calcium carbonate”. ... and at the present day (the current state of knowledge), the word: "NORMAL" should suffice for us, the rest is really "pure speculation" ... -
Berényi Péter at 18:35 PM on 25 June 2010September 2010 Arctic Ice Extent Handicapping Via ARCUS
#18 Neven at 11:37 AM on 25 June, 2010 Peter, maybe you can add a ice thickness colour index. Here you go.
Current extent of ice thicker than 2 m in arctic basin is almost twice as much as it used to be last year, same date. Beaufort Gyre is working hard this year, ice thickness at its center is getting close to 4 m (due to ridging).
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Peter Hogarth at 18:32 PM on 25 June 2010Ocean acidification
33.Berényi Péter at 08:51 AM on 25 June, 2010 From Manzello 2010: "These naturally high-CO2 reefs persist near the Ωarag distributional threshold for coral reefs and are thus expected to be the first and most affected by ocean acidification" -
Arkadiusz Semczyszak at 18:31 PM on 25 June 2010Ocean acidification
"... complicated ..." So let us focus on Australia, the Australian scientists, Australian coral reef ... "Coral reefs under rapid climate change and ocean acidification" Hoegh-Guldberg et al., 2007, "Repeated bleaching episodes in the same coral assemblages and the increasing scale and frequency of coral bleaching have been cited as evidence that corals have exhausted their genetic capacity to adapt to rising sea surface temperatures ." "Indeed, the effects of temperature and acidification on even the most basic vital rates in corals, such as growth, mortality, and fecundity, are LARGELY UNKNOWN, as are the physiological trade-offs among these traits." "Consequently, the sensitivity of population growth to climate-induced changes in vital rates remains almost COMPLETELY UNEXPLORED. In the absence of LONG-TERM [!] demographic studies to detect temporal trends in life history traits, predicting rates of adaptation, and whether they will be exceeded by rates of environmental change, is PURE SPECULATION." "The majority of coral generation times, however, are still long (decades) relative to the ACCELERATING PACE of climate change, throwing doubt on the scope of most coral species for RAPID adaptation ..." And here (again) back, "ab ovum": "Abrupt tropical climate change: Past and present"(Thompson et al., 2006). If the former (including even those fairly recent) changes were more violent than the present or similar (and a lot to suggest it), then this question: "It took millions of years for these organisms [calcifying marine organisms] and ecosystems to recover."; is not the slightest importance ... Kleypas et al (2006) : " It is certain that net production of CaCO3 will decrease in the future", "Determine the calcification response to elevated CO2 in . . ", " .. in many cases even the sign of the biochemical response, let alone the magnitude, is UNCERTAIN ". Lough and Barnes (1997) found that "the 20th century has witnessed the second highest period of above average calcification in the past 237 years." Currently, however: "The study shows that the biggest and most robust Porites corals on Australia's Great Barrier Reef have slowed their growth by more than 14 percent since the "tipping point" year of 1990." "The data suggest that this severe and sudden decline in calcification is unprecedented in at least 400 years," Lough: "It is cause for extreme concern that such changes are already evident, with the RELATIVELY MODEST CLIMATE CHANGES observed to date, in the world's best protected and managed coral reef ecosystem," ... however: "The causes of this sharp decline remain UNKNOWN, but our study suggests that the combination of increasing temperature stress and ocean acidification may be diminishing the ability of Great Barrier Reef corals to deposit calcium carbonate," "Dr Lough said there had been some concern that coral growth has been declining in recent times. "However, data from density bands place these results into a larger context. Density bands show that coral growth and calcification on the Great Barrier Reef vary considerably over time."" "Coral records show that there have been several major increases and decreases over the past several centuries." Generally conclusion: "THE CURRENT DECLINE APPEARS TO BE A RETURN TO MORE NORMAL GROWTH CONDITIONS FROM HIGH GROWTH RATES EARLIER THIS CENTURY". ... ??? (http://www.reef.crc.org.au/publications/explore/feat37.html) -
Berényi Péter at 18:05 PM on 25 June 2010Ocean acidification
Compare it to distribution of Chlorophyll a concentration along the tropics. Notice huge deep blue desert in south Pacific with rather high pH.
At higher latitudes it's a different story, as CO2 solubility increases with decreasing water temperature.
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Berényi Péter at 17:30 PM on 25 June 2010How many climate scientists are climate skeptics?
Re: Moderator Response: The last several comments already are collected together. Click the "Recent Comments" link in the blue horizontal bar that is at the top of every page. Each comment's time-date stamp is a link to that particular comment's original location.Thanks, I haven't noticed. It helps a lot. As soon as people start using it the discussion can get more focused. -
Doug Bostrom at 16:19 PM on 25 June 2010September 2010 Arctic Ice Extent Handicapping Via ARCUS
Further to HR's thoughts about psychological influences on predictions, I took a closer look at the rationales and methods described in the supporting material for the SEARCH collection. With the exception of Wilson and Wellman it's hard to see where the psych angle fits in. I suspect the undershoots have a lot to do w/the statistical input to the various models in play but I don't have the chops to prove that, rather I'll just surmise that if the trajectory of past statistics is overwhelmed by variability expressing itself as an upswing the upshot would tend to be an undershoot. Doubtless the expert cohort in the SEARCH participants could help to clarify that. -
Berényi Péter at 15:57 PM on 25 June 2010Ocean acidification
#34 VoxRat at 09:47 AM on 25 June, 2010 Do you know what the pH was? Yessir!
Guess where upwelling occurs.
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RSVP at 15:38 PM on 25 June 2010How Jo Nova doesn't get past climate change
<> Quite prophetic assuming this was before the internet (for the first part of the quote), and more so if you consider how quickly certain comments on this site get deleted. -
scaddenp at 14:16 PM on 25 June 2010September 2010 Arctic Ice Extent Handicapping Via ARCUS
"Sept/Oct 2007 levels that caused panic at the IPCC". Reference please for this "IPCC panic". However the rate of decline in ice is getting well beyond IPCC predictions so it is a cause for concern if it persists. -
Neven at 14:06 PM on 25 June 2010September 2010 Arctic Ice Extent Handicapping Via ARCUS
Panic at the IPCC? The IPCC is like 50 years behind the current trend. No, the IPCC is much too skeptic on this point (and on sea level rise). I have passed the phase of apeshit. I don't the envy all the people who still have it in front them. I had several years to digest it. ;-) -
gallopingcamel at 13:57 PM on 25 June 2010September 2010 Arctic Ice Extent Handicapping Via ARCUS
Given that the ice sheet extent is on track to dip below the record low Sept/Oct 2007 levels that caused panic at the IPCC, you folks are showing admirable restraint. Nobody is going ape s**t. As usual BP is way above my pay grade but I will keep coming back in the hope that my grey cells will improve. -
Neven at 13:44 PM on 25 June 2010September 2010 Arctic Ice Extent Handicapping Via ARCUS
Of course it's all down to weather, but it's the preconditioning (or thinning if you will) of the ice that makes the influence of different weather patterns relevant. In the 80's there were also freak years like 2007, but because the multiyear ice was so thick, the minimum sea ice extent easily stayed above, what was it, 8 million square km. I've also written a piece on the Cryosphere Today archive data and the discrepancy with the daily ice concentration map on the front page. No conclusions, unfortunately, but the archive maps look fishy to me. BTW, one of the NOAA webcams stationed at the North Pole seems to be showing a first melt pond. -
HumanityRules at 13:09 PM on 25 June 2010September 2010 Arctic Ice Extent Handicapping Via ARCUS
22 Neven So what you're suggesting is it's all down to the weather? -
HumanityRules at 13:06 PM on 25 June 2010September 2010 Arctic Ice Extent Handicapping Via ARCUS
Given were all in baseless prediction mode I'll give it a go. I'm going to agree with 14 Berényi Péter and disagree with 10 CBDunkerson that the central Arctic Ocean ice is looking better through this winter than the past few years. I think the archive data from Cryosphere Today also suggests this. I think people here were right in previous discussions that the greater ice accumulation at some parts of the periphery this winter was destined to quickly melt as witnessed by the steep decline over the past few months. So I predict through the summer the melt will slow more quickly than previous years due to the better central Arctic ice and we'll end up somewhere near the 30year trend average plus a few tenth of a million sq km because I'm an optimist. So I'll go with 5.4 I also predict that PIOMAS will underestimate again this year. -
Neven at 12:46 PM on 25 June 2010September 2010 Arctic Ice Extent Handicapping Via ARCUS
It's not so surprising, considering the fact that 2007 took everyone completely off guard. Had the weather conditions of 2008 and 2009 come anywhere near those of 2007 the record would have been broken again. The same goes for this year. The ice in the Arctic Basin has perhaps recovered somewhat, but it is irrelevant if we get 2007 weather conditions. -
HumanityRules at 12:11 PM on 25 June 2010September 2010 Arctic Ice Extent Handicapping Via ARCUS
I should just point out 2008 predictions weren't as bad as 2009. 11/14 underpredicted the ice extent (3/14 overpredicted) but there still seems a bias towards low predictions. -
Doug Bostrom at 12:04 PM on 25 June 2010September 2010 Arctic Ice Extent Handicapping Via ARCUS
HR, thanks for calling those past predictions to our attention. I should have included those but confess I did not dig back to find 'em. What we know of human nature suggests that it would indeed be difficult to entirely isolate our psychology from the 2007 surprise. For my part I remain impressed by the "Joe Public" prediction, particularly as it was made in February. I'd love to see a breakout of the distribution but it's not in the supporting materials. -
HumanityRules at 11:49 AM on 25 June 2010September 2010 Arctic Ice Extent Handicapping Via ARCUS
It appears that SEARCH have been gathering Sept minima for 3 years. Fortunately they archive the 2008 AND 2009 predictions. A similar clustering occurred in both those years unfortunately all predictions underestimated the actual ice extents. So the clustering this year does not necessarily indicate were the final extent will be. I can't help thinking that the extraordinary ice extent in 2007 is in some way playing through these prediction methods to give a low bias. If it's not this I'd love to know what's causing this bias? On a side note. The recent WUWT ice discussions have largely centred around the skill of PIPS v2 and PIOMAS to predict ice volume. PIPS don't seem to have submitted predictions to SEARCH but PIOMAS have (in the shape of Zhang et al). The PIOMAS predictions for 2009 seem particularly poor giving the 2nd worst prediction in May and 4th worst in June.
I see from Doug's article Zhang is on the low side for 2010 again.
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Neven at 11:37 AM on 25 June 2010September 2010 Arctic Ice Extent Handicapping Via ARCUS
That GIF is using 2% of my CPU. BP, you're increasing my carbon footprint. Go to the PIPS webpage and hear your CPU fan spin up (because of the snow effect in the background). :-) Peter, maybe you can add a ice thickness colour index. -
Doug Bostrom at 11:12 AM on 25 June 2010September 2010 Arctic Ice Extent Handicapping Via ARCUS
Squint hard enough and you can see whatever you want. Frolicking polar bears, submariners with Mai Tais, whatever. That GIF is using 2% of my CPU. BP, you're increasing my carbon footprint. -
Neven at 10:59 AM on 25 June 2010September 2010 Arctic Ice Extent Handicapping Via ARCUS
Thanks, Doug. I figured a summary of WUWT Arctic sea ice chest-thumping could prove to be helpful in case we get a new record. It's a dirty job, but someone's got to do it. ;-)
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