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Kayell at 16:44 PM on 17 April 2013Global Warming is Accelerating, but it's Still Groundhog Day at the Daily Mail
I'm interested to know what specific thermodynamic mechanism is being utilized by the amounting atmospheric CO2 to restrain the release of the absorbed solar heat from the ocean so as to raise the OHC without warming the troposphere and the surface first ...?
Also, you should drop the term 'unprecedented' in your first key point. There are absolutely no other historical periods prior to the last ~8 years to compare with when it comes to deep ocean heat content (data coverage).
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Doug Hutcheson at 10:04 AM on 17 April 2013Further Comments on The Economist's Take on Climate Sensitivity
Tristan @ 34, building sea walls only works to a limited extent.
Firstly, one needs to know how high to build them, secondly there are logistical problems about where to build them and, thirdly, one needs to take cognisance of the underlying geological structures, to be sure water cannot penetrate beneath them (I understand much of Florida is not suitable for protection by sea walls, for this reason).
The first consideration is the most important: how high does one need to build a sea wall, to ensure it is high enough to cope with the maximum possible seal level rise and that it is not liable to being overtopped by a storm surge?
Sea walls do not work in delta environments like Bangladesh and do not help infrastructure that relies upon being close to, but above, sea level. Such items as ports and industries relying upon seawater for cooling come to mind.
This discussion is going off-topic, so I suggest you continue on a more appropriate thread.
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william5331 at 06:00 AM on 17 April 2013Guemas et al. Attribute Slowed Surface Warming to the Oceans
Esop, That situation may end in a rather large speed bump. If you look at the NSIDC web site for October, they report about half way down, warm air over open water and winds from the south (SW with Coriolis). That sounds very much like a short, autumn reversal of the Polar Hadley cell. With more open water each year, this situation should occur, on average, earlier and earlier each year. Instead of climate zones creeping northward at about 4km pa, we should have a lurch northward as you no longer have surface air pouring southward compressing the climate zones. This should raise the temperature averages rather sharply. It will be interesting to see the escalator graph ten years from now.
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shoyemore at 05:42 AM on 17 April 2013It’s getting hotter – despite cooling from cosmic rays
It's seems that a blast of cosmic radiation struck the earth in 774AD, apparently without any climatic effects, or at least only short term ones.
http://www.bbc.co.uk/news/science-environment-21082617
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dana1981 at 04:29 AM on 17 April 2013Guemas et al. Attribute Slowed Surface Warming to the Oceans
Argo data are incorporated into the ORAS4 reanalysis data set.
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Antarctica is gaining ice
John Hartz - While not an SkS moderator, I might suggest that presenting 3-4 repeats of the same claims while disregarding other comments to be 'troll-like' behavior, and should probably be rewarded with the staged moderation warnings seen in other contexts here.
Moderator Response:[DB] All parties: please return the discussion to the topic of this thread, Antarctica is gaining ice.
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kampmannpeine at 03:18 AM on 17 April 2013Guemas et al. Attribute Slowed Surface Warming to the Oceans
@Ray and others:
I do - like you - not understand why the ARGO-data are not being used in order to help answer this issue ... These floats are going deep down to 2000 m ... measure amongst others temperature. So does anybody here can give a reason why not?
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dana1981 at 02:58 AM on 17 April 2013It’s getting hotter – despite cooling from cosmic rays
Composer - correct. Galactic cosmic ray flux on Earth is dictated by the solar magnetic field strength. Higher solar activity means a stronger solar magnetic field, which means more GCRs deflected, meaning fewer GCRs on Earth, and hypothetically less cloudcover and thus more warming. GCRs are hypothetically basically a solar amplifier.
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Old Mole at 02:54 AM on 17 April 2013To frack or not to frack?
People may not know, or have forgotten, that vroomie is from Wyoming. Wyoming has a peculiar set of circumstances that make his concerns valid, chief among them that the aquifers there are deep and the shale beds are shallow ... typically 3000 feet below the surface, not the 6000 feet or more in the Marcellus, Natchez, or Texas shale beds. In his case, the chance of the fracking process itself, not just holes drilled through the aquifer, causing contamination is real. The EPA issued preliminary findings a couple of years ago to that effect around Pavilion a couple of years ago, although those findings were predictably contested by the usual suspects including James Inhofe.
He also makes the point that it takes several million gallons of fresh water to frack a well, but doesn't talk about what happens to the contaminated water afterwards. Ideally, it is injected into older, retired wells, but I am not sure there are that many in Wyoming, or at least enough of them to cope with the demand caused by the fracking boom. What more typically happens there is the bad water is pumped into temporary holding ponds of earth with plastic liners, and left to evaporate. If they fail, they can do a great deal of local damage.
On a side note, is that where the discrepancy in fugitive emissions between conventional and fracked gas wells comes from? Is there that much methane dissolved in the water/frack fluid mixture, or is it some other factor I haven't considered? While I have no cause to doubt the study findings, I am at a loss to explain so large a discrepancy.
If he wants to know what is in the fracking fluids, all he has to do is convince the Wyoming state legislature to mandate disclosure, like Texas did. That may be a hard sell in the home of Dick Cheney, but there are enough pissed off ranchers to get it done if they got themselves organized.
P.S. The Imperial Valley doesn't have an aquifer to speak of ... they get all of their water out of a big ditch from the Imperial Dam on the Colorado River. You might be thinking of the Westlands Water District in the northwest San Joaquin Valley, which did trash their ground water so badly that they have had to take major acreage out of production.
Best wishes,
Mole
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John Hartz at 02:33 AM on 17 April 2013Antarctica is gaining ice
Speaking of the complexity of Antarctica's climate...
Two different areas of Antarctica tell two very different stories about how climate change might be affecting ice melt. The data appear to confirm that climate change impacts can be very local.
Source: Antarctic ice tells conflicting story about climate change's role in big melt by Pete Spotts, The Christian Science Monitor, Apr 16, 2013
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Bruce at 02:13 AM on 17 April 2013Guemas et al. Attribute Slowed Surface Warming to the Oceans
Here is a good summary by Purkey , with nod to the data deficit in the abyssal waters. http://www.livescience.com/28248-deep-ocean-warming.html -
Composer99 at 02:04 AM on 17 April 2013It’s getting hotter – despite cooling from cosmic rays
Granting my layperson status, but from what I have seen, cosmic rays affecting the climate is a roundabout form of the Sun affecting the climate (since cosmic ray incidence upon the Earth appears to be modulated by solar activity).
One notes the text in the OP describes:
Before the 1970s, temperature did seem to follow levels of cosmic rays. This is what caused some scientists to believe that there was a relationship between the two. After the 1970s, this relationship broke down. For the next 15 years, changes in temperature were happening before changes in cosmic rays. After this, temperature and cosmic ray counts moved in opposite directions.
and this appears to coincide with an identical relationship between changes in TSI and changes in global mean temperature, a relationship that experiences a similar breakdown over the same time frame.
So the bottom line seems to me that if the influence cosmic rays have on Earth climate follows from solar influence, rather than acting independently, then given solar activity & Earth climate are no longer conjoined, it follows that cosmic ray activity and & Earth climate will also no longer be conjoined.
(Unrelated formatting note: the phrase "And here is the final nail in the coffin for this excuse" appears twice in the final paragraph before the bibliography section.)
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MA Rodger at 01:39 AM on 17 April 2013The anthropogenic global warming rate: Is it steady for the last 100 years?
KK Tung @28.
You say "...they all lie within the range of uncertainty of aerosol cooling stated in IPCC AR4." I have never seen such a statement of uncertainty within IPCC AR4. The best I can find is in 2.9.5 Time Evolution of Radiative Forcing and Surface Forcing - "As for RF, it is difficult to specify uncertainties in the temporal evolution, as emissions and concentrations for all but the LLGHGs are not well constrained."
This strongly suggests no such quantified range is defined. Is it possible for a pointer to the statement you reference? It is possible you are inferring the 'Time Evolution' profile uncertainty (ie how bent, how smooth) from the widely known uncertainty presented within IPCC AR4 for at a single date in time (eg the year 2000).
The sense of the word "competing" I used was actually taken from Tung&Chou13 to mean as well as being in the same contest, also in conflict with each other (that is not in the same team), the latter being absent from your use.
You say of multi-decadal wobbling of the global temperature record in Tung&Chou13 "If it is interpreted as natural and related to the Atlantic Multidecadal Oscillation (AMO), then the trend attributed to anthropogenic arming should be significantly reduced after 1980, when the AMO was in a rising phase. However, if it is forced by time-varying aerosol loadings, it should properly be interpreted as part of an accelerating anthropogenic trend. We argue that the former is true, using information from the preindustrial era."
You seem to be reluctant to affirm the position that the smooth forcing profile is consistent only with "the former" and the bent forcing profile only consistent with 'the latter'.
Can you affirm this? Or otherwise, can you indicate the reason it cannot be? -
Rob Honeycutt at 01:39 AM on 17 April 2013Real Skepticism About the New Marcott 'Hockey Stick'
Brandon @ 78.... I have to say, that just strikes me as desperately trying to avoid the obvious. You're quibbling over details of joinery in the woodwork whilst the house burns behind you.
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John Mason at 01:12 AM on 17 April 2013The History of Climate Science
That's certainly something we are discussing doing. Sending someone a PDF often better guarantees a reading than sending someone a hyperlink.
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Dikran Marsupial at 00:42 AM on 17 April 2013Models are unreliable
@bouke O.K. substitute "are substantially influenced by" for "rest on": "What policy decisions are substantially influenced by predictions of sea ice extent?"
I agree that "do nothing" is a policy decision, nothing I wrote suggests otherwise. Funding projects on changes in weather patterns due to changes in Arctic sea ice extent on the other hand is not a policy decision (grants are awarded competitively and are effectively selected by peer review, although there are also calls for proposals on particular topics). However, this is still not a decision where deficiencies in the models has any real impact on the decision as the observations are perfectly clear, so again it doesn't support your stated concern."To limit CO2 emissions to a specific target" IS a policy decision, but is not one where model projections of Arctic sea ice extent have big impact for the simple reason that the reason for the limit on CO2 is to limit the effects of GLOBAL climate change. Arctic sea ice at this point is essentially history more or less no matter what we do to limit CO2, so anybody arguing that CO2 should be limited to save Arctic sea ice extent has pretty much missed the boat.
Essentially the point is that for Arctic sea ice extent, the observations tell you what is happening, the models predict that the Arctic sea ice will last longer than the observations suggest to the extent that we know that their projections are wrong, and hence nobody should be taking them sufficiently seriously as a basis for policy.
Now you think that they do have an effect on policy, but do you have any evidence to support that?
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archie lever at 00:00 AM on 17 April 2013Further Comments on The Economist's Take on Climate Sensitivity
Tom Dayton @29
The Economist's authors quote several 'peer reviewed' sources in relation to climate sensitivity and other factors affecting global temperatures. Again it comes down to a matter of opinion as to whose source will be proven more accurate in the future.
The article clearly says that the weight of recent evidence has moved the centre of gravity for equilibrium sensitivity (assumed 3 degree celcius up until now) closer to 2 degrees celcius or lower. This implies that forcings affected by clouds, water vapour feedbacks, ENSO, ocean heat absorption are not as well known as supposed in current modelling and hence the divergence over the last 10-12 years.
It also implies that policy makers have more time to reduce CO2 emissions and move to cleaner energy sources.
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shoyemore at 22:44 PM on 16 April 2013On Climate Sensitivity and Matt Ridley's Irrational Optimism
Did this get overlooked, being just before Christmas?
Lweis has just published his paper so I hope we see a fuller discussion than of just a blogpost.
http://journals.ametsoc.org/doi/abs/10.1175/JCLI-D-12-00473.1?af=R
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neilrieck at 21:01 PM on 16 April 2013The History of Climate Science
This is a great introduction to climate science. Lots of friends and relatives do not have the time or intrest to read a full book on the subject like Weart's "The Discovery of Global Warming" so might I suggest that this article be converted into a PDF for referal.
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Tristan at 19:02 PM on 16 April 2013Further Comments on The Economist's Take on Climate Sensitivity
Isn't it likely to be more cost effective to build sea walls than move things?
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bouke at 18:29 PM on 16 April 2013Models are unreliable
@Dikran
You suggested that the lack of skill in the models is an issue as they are used to decide policy. You also clarified that the lack of skill you mentioned was specific to sea ice extent (your post 610)
Agreed. Well, sea ice extent minimum to be more precise.
However there are no policy decisions that rest on prediction of sea ice extent, which reveals that you concerns are baseless.
Disagreed. Firstly, I think 'rest on' is too strong a wording for the conclusion you are trying to make. It is enough for a policy decision to be influenced by the prediction, to make my concerns not baseless.
Secondly, perhaps we disagree on what constitutes a policy decision. I think doing nothing about a (perceived) problem is an actual policy decision, equally valid as doing something. It may be the best policy decision, actually. But I guess you want specifics of policy decisions that are not taken.
"To fund research to study changes in weather patterns as a consequence of a seasonally ice free arctic" is a policy decision. The current policy is not to spend the money. I think this decision is influenced by the prediction of sea ice extent minimum.
"To limit CO2 emissions to a specific target" is a policy decision. One of the political parties in my country (the VVD) say they have a CO2 emissions target, but they don't spend funds or propose regulation to achieve this goal. In effect, they are doing nothing. I think this decision is influenced by the prediction of sea ice extent minimum. I think the influence is small, but real. If a consequence of climate change may be right around the corner, it becomes less defensible to do nothing.
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scaddenp at 17:37 PM on 16 April 2013Real Skepticism About the New Marcott 'Hockey Stick'
Brandon, the graph very obviously needs 3 parts - past, present, future. I would be quite happy with a gap (though I think other as yet unpublished analyses deal with uptick issues). If you are worried about whether they meet, it seems to imply you have problems with the calibration of the proxies? Instead of me trying to guess, can you explain exactly why do think it is so significant?
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Doug Hutcheson at 17:05 PM on 16 April 2013Further Comments on The Economist's Take on Climate Sensitivity
I think it is useful to consider what infrastructure will be rendered unserviceable by sea level rise.
Ports, of course, will be affected, impacting upon international trade. Many cities are in existence because they are trade centres, meaning that much of their infrastructure is low lying. Coastal airports around the world are often just above sea level, for example. So also are many heavy industries, power generation facilities (including nuclear: cf Fukashima), chemical plants, oil refineries and so forth. Then there are the road and rail links which service such sites.
Altogether, the amount of land surface lost to SLR is important, but the dislocations to economies, due to the existing uses of such land, could be critical. It would seem we need to start relocating our centres of human activity above the new high tide line, well before they are placed at risk.
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Brandon Shollenberger at 15:41 PM on 16 April 2013Real Skepticism About the New Marcott 'Hockey Stick'
I feel I should thank Tom Curtis for his comment @62 as he is the only person who has responded to what I actually said. Hopefully chriskoz, Rob Honeycutt, KR and dana1981 can understand what I actually said after reading his comment.
However, I disagree with this part of his response:
2) Had he done so, as Jos Hagelaars did above, it would have made no difference in visual impact, as can be easilly seen above. This is true even if the "blade" is omitted and the instrumental record is shown. It follows that you are quibbling.
I don't think it makes "no difference in visual impact" to have an entirely new record added to a graph. Even if the resulting curve is (nearly) the same, there is an obvious difference introduced when you have to have three records as opposed to two. The additional complexity alone is important. The fact an over-simplification gives a "right" answer doesn't stop it from being an over-simplification.
The graph in question shows projected temperatures flowing directly from the reconstructed temperatures. That's a very simple image which relies on the two records meeting at an exact point. If you remove the uptick, they no longer meet. That's a significant change. You may be able to make another significant change to combat that, but that doesn't mean the original version is correct or appropriate.
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Tom Curtis at 14:32 PM on 16 April 2013Further Comments on The Economist's Take on Climate Sensitivity
Climate Bob @31, while it is largely true that New Orleans goes underwater at 1 meter of sea level rise, for most coastal cities a 1 meter sea level rise inundates only a small faction of their area. In Australia's case, it is estimated that $300 billion dollars worth of property would be innundated by an approximately 1 meter sea level rise (actually 1.1 meter). That sounds like a lot, until put into context by Australia's US$ 1.37 trillion economy. In context, however, it is seen that a sea level rise of 1.1 meters will inundate 4.6% of Australia's GDP in property, over a period of 50 to 100 years. The annualized cost would be a minor drain on Australia's budget at most.
There are some regions where the effects of sea level rise are far greater, notably the Nile Delta and the Ganges Delta (aka Bangladesh). The tragedy in those cases will not, however, be in the net cost of sea level rise as a portion of the world's economy (which will be small) but that Egypt and Bangladesh will be left carying the massive costs in national terms without significant assistance. Sea level rise raises serious issues about justice, but few about economics.
However, overstating the case ("many major cities go underwater") is not helpfull. Nor does overstating the case on agriculture, which will not "cease" at 3 degees C, although it may be severely limited and is a far greater concern than sea level rise. A 10% reduction in land area for cities is hardly consequential given the total land area of the Earth. A 10% reduction in agricultural yield may be truly catastrophic, especially given increasing populations. But equating such uncertain reductions with "agriculture ceas[ing]" is absurd.
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Climate Bob at 12:27 PM on 16 April 2013Further Comments on The Economist's Take on Climate Sensitivity
This discussion of the finer point of the future temperature are interesting but in reallity farming as we know it stops at 3C and many major cities go underwater at 1 meter. It is also a gradient of disaster so that we will be under a lot of stress leading up to that. my web site tries to alert people in NZ to the problems in many areas.
http://www.climateoutcome.kiwi.nz/
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DSL at 10:51 AM on 16 April 2013Antarctica is gaining ice
How much time and energy does it take to quote mine, particularly when the targeted conclusion is going to be easily dismissed by readily available research? What a complete waste for Kevin, but what a nice, short example of the James Taylor School of Journalism for SkS.
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Rob Honeycutt at 10:49 AM on 16 April 2013Antarctica is gaining ice
I think it's a very good lesson in how "fake skepticism" works. You start with your preferred conclusion, find exceptions in the research that support than conclusion, then avoid attempting to understand the issue as a whole.
I have to admit, I see the attraction to doing this! It takes far less work to operate this way. Antarctica, in particular, is incredibly complicated (as if any aspect of climate change is simple). It's not easy to go through all the information and fully grasp what's going on. And it's especially hard when you clearly do not want to accept what scientists are saying.
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Antarctica is gaining ice
Readers - There is actually a useful lesson in the last exchange(s) with Kevin. What he did was to selectively quote-mine old analyses (ignoring the last quarter-century of work), cherry-pick the data (East Antarctic while ignoring Antarctica as a whole), and misrepresent implications (wrongly equating increased snowfall with mass balance, ignoring greatly increased melt and calving). And concluding with a Bizzaro-world interpretation exactly opposite that of the IPCC.
This is in fact a fairly common denier tactic - select tiny bits of the science out of context and miscast them in contradiction to the whole. I strongly suggest reading the original sources (which isn't difficult if you start with abstracts and work your way up as you can or as desired), and check the quotes and sources.
IMO denial is broadcast with selective reading and presentation, some of which (see anything from Lord Monckton) is simply false. Armor yourself by checking the assertions from all participants.
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Bob Lacatena at 09:23 AM on 16 April 2013Antarctica is gaining ice
We know that Kevin has recused himself from participation, but lets take a quick review of insane denial, and clear things up along the way.
Kevin first quoted the 1990 IPCC First Accessment Report as claiming that Antarctica would experience increased snowfall. Kevin (1) quoted a 23 year old report and (2) proceeded to conflate increased snow fall with increased land ice. He also ignored the balance of the actual report, which very clearly lays out the details, as understood at that time, of Antarctic ice gain and loss. The tone of that report is nothing like Kevin's quote suggests.
When called on this, Kevin next quoted the 2007 IPPC Fourth Assessment Report -- but he chose to quote the FAR's review of the TAR —the Third Assessment Report, from 2001, 12 years ago. That section was a mere review of the previous report, in preparation for the more recent update. What's the point?
Somehow he skipped over the actual content of the FAR, which even more clearly than the first two reports discusses the ice gain and loss in Antarctica, including this:
Zwally et al. (2006) obtained SRALT coverage for about 80% of the ice sheet, including some portions of the Antarctic Peninsula, and interpolated to the rest of the ice sheet. The resulting balance included West Antarctic loss of 47 ± 4 Gt yr–1, East Antarctic gain of 17 ± 11 Gt yr–1 and overall loss of 30 ± 12 Gt yr–1.
Anyone can follow the link provided by KR to the actual page. People can judge for themselves what the IPCC has actually said about the subject, and how their understanding has progressed over time.
It is very, very important when faux-skepticism raises its ugly head to follow the quotes and the denial to the source, read everything with an open mind, and to understand what is truly there — not merely what some denier chooses to misrepresent.
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John Hartz at 06:46 AM on 16 April 2013Antarctica is gaining ice
DSL & Rob Honeycutt:
Kevin fell through the thin ice of slogannering and his most recent comment was deleted.
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sidd at 06:33 AM on 16 April 2013Guemas et al. Attribute Slowed Surface Warming to the Oceans
1)Guemas et al show 3 yr accumulation of OHC, Balmaseda show total OHC integrated over the whole observational period. So Guemas is related to the derivative of the Balmaseda grafs
2)I have differenced the Balmaseda grafs to show heat into various layers of ocean. After 2006, 300m-700m layer shows little OHC increase.
3)700-2000 m layer shows little heat uptake from 2000-2006
http://membrane.com/sidd/balmaseda-2013.html
sidd
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Rob Honeycutt at 06:29 AM on 16 April 2013Antarctica is gaining ice
Kevin... "The ice sheet is predicted to thicken" ≠ Total ice mass balance will increase.
You're cherry picking and vastly oversimplifying.
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DSL at 06:28 AM on 16 April 2013Antarctica is gaining ice
Kevin, where do the main articles rely on AR4? SkS is not a defense of AR4, nor would it matter in this case (see KR's response).
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Kevin8233 at 06:15 AM on 16 April 2013Antarctica is gaining ice
DSL,
I stated earlier that AR4 did not make a prediction, the prediction came from the TAR.
So, assume that AR4 is correct, and no trend is there. How does SkS come up with this thread then? Losing or gaining ice, sea or land, has no bearing, right?
Moderator Response:[JH] You are now skating on the thin ice of sloganeering. Please cese and desist or face the consequences.
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John Hartz at 06:14 AM on 16 April 2013Antarctica is gaining ice
Everyone:
Please resist the temptation to "dogpile" on Kevin. Let his current conversation with DSL play out without interjecting comments.
Moderator Response:KR excepted.
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Antarctica is gaining ice
Kevin - "...the latest prediction that the IPCC has made, predicts that Antartica will gain ice as temp increases."
That would be completely incorrect. From IPCC AR4, Chapter 4.6.2.2:
Taking the Rignot and Thomas (2002), Zwally et al. (2006) and Rignot et al. (2005) results as providing the most complete antarctic coverage suggests ice sheet thinning of about 60 Gt yr–1... [ ]
Assessment of the data and techniques suggests overall Antarctic Ice Sheet mass balance ranging from growth of 50 Gt yr–1 to shrinkage of 200 Gt yr–1 from 1993 to 2003. [ ]
Acceleration of mass loss is likely to have occurred, but not so dramatically as in Greenland.
From the same document, FAQ 4.1:
Taken together, the ice sheets of Greenland and Antarctica are very likely shrinking, with Greenland contributing about 0.2 ± 0.1 mm yr–1 and Antarctica contributing 0.2 ± 0.35 mm yr–1 to sea level rise over the period 1993 to 2003. There is evidence of accelerated loss through 2005. Thickening of high-altitude, cold regions of Greenland and East Antarctica, perhaps from increased snowfall, has been more than offset by thinning in coastal regions of Greenland and West Antarctica in response to increased ice outflow and increased Greenland surface melting. [ ]
The geographically widespread nature of these snow and ice changes suggests that widespread warming is the cause of the Earth’s overall loss of ice.
[Emphasis in both quotes added]
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You have been quote-mining old reports, not reading or incorporating the current science or observations, and clearly only looking at one side of the mass-balance equation while ignoring increased melting. I dislike saying this, but your last few posts have been nonsensical.
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Rob Painting at 06:10 AM on 16 April 2013Guemas et al. Attribute Slowed Surface Warming to the Oceans
Ray - The claims made in this paper (Guemas [2013]) do not seem to match the observations. Warming has been occurring in the deep ocean. As we have made clear ever since Levitus (2012) was published. Heat reaching the deep ocean cannot be accounted for by simply measuring ocean temperatures in the 0-700 metre layer - as is explained in the post you linked to.
As for sea surface temperatures being cooler-than-normal over the last decade, that's consistent with a La Nina-dominant period. The tilting of the thermocline in the tropical Pacific buries heat in the subsurface layers during La Nina periods. This occurs in the western tropical Pacific and the strengthening westerly trade winds cause upwelling of cold acidified water from the deep off the western coast of the American continent. Burial of heat in the subsurface western tropical Pacific plus upwelled cold water on the surface in the eastern tropical Pacific equals cooler-than-normal heat exchanged with the atmosphere during La Nina, and La Nina-dominant periods.
Not having read the Guermas paper, I have no idea why they are dismissive of measurements showing unprecedented warming in the deep ocean.
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DSL at 06:01 AM on 16 April 2013Antarctica is gaining ice
AR4 Ch 4.6.3.1 (2007): "Long-term data are very sparse, precluding confident identification of continent-wide trends."
"We combined an ensemble of satellite altimetry, interferometry, and gravimetry data sets using common geographical regions, time intervals, and models of surface mass balance and glacial isostatic adjustment to estimate the mass balance of Earth’s polar ice sheets. We find that there is good agreement between different satellite methods—especially in Greenland and West Antarctica—and that combining satellite data sets leads to greater certainty. Between 1992 and 2011, the ice sheets of Greenland, East Antarctica, West Antarctica, and the Antarctic Peninsula changed in mass by –142 ± 49, +14 ± 43, –65 ± 26, and –20 ± 14 gigatonnes year−1, respectively. Since 1992, the polar ice sheets have contributed, on average, 0.59 ± 0.20 millimeter year−1 to the rate of global sea-level rise."
Antarctica, like Greenland, can show mass increase in the interior while still showing an overall net loss. That may be the source of some confusion.
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Kevin8233 at 05:37 AM on 16 April 2013Antarctica is gaining ice
DSL,
As I stated earlier, the latest prediction that the IPCC has made, predicts that Antartica will gain ice as temp increases.
The whole gist of this particular thread is that the ice will go down as temp increases, and that "Deniers" were incorrect in their belief that the increase in ice was contrary to predictions because it was only sea ice that increased, not Land ice.
I noted that there is a discrepancy in that the IPCC predicted an increase in Land ice, not a decrease. It very well could be that you are correct in that this thread was created after new research indicated that Land ice should decrease and not increase.
The AR4 did in fact come out prior to 2008, having come out in 2007 (with research obviously prior to that).
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DSL at 05:25 AM on 16 April 2013Antarctica is gaining ice
Kevin, the bottom line is that you're quoting FAR or TAR as a representative position. It's not. AR4 summarizes FAR but does not say, "And we still draw those conclusions." Discussing F/TAR might be interesting, but it's not relevant. AR4 is already being set aside. The science upon which AR5 rests is already in publication. Refer to it, as AR5 will. We now know more about the Antarctic. Get back into your time machine and return to the present.
Or don't, but don't be surprised if people ignore you, because F/TAR is just not that interesting.
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Kevin8233 at 05:20 AM on 16 April 2013Antarctica is gaining ice
Bob Loblaw,
How about the AR4's summary? The ice sheet is predicted to thicken!
I have shown IPCC's prediction that the ice sheet will thicken. Does someone have an IPCC prediction that the ice sheet will lessen?
Moderator Response:[JH] You seem to be more interested in playing "Gotcha" games with other commentors than engaging in a civil discussion of the science. As far as I am concerned, playing Gotcha is sloganeering which is banned by the SkS Comments Policy. Please cease and desist. If you do not, your posts will be summarily deleted.
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Kevin8233 at 05:13 AM on 16 April 2013Antarctica is gaining ice
Sphaerica,
How do you read the quote from the AR4?
Key regional projections highlighted in the TAR
Increased melting of Arctic glaciers and the Greenland ice sheet, but thickening of the Antarctic ice sheet due to increased precipitation, were projected.
This is not cherry picked. This is AR4's summary of the TAR's prediction. It is not my interpretation. I copied the words directly.
How about the actual prediction from the TAR? Models predict.... Not Kevin interprets these models to predict. It says the models predict.
Explain how I am not understanding these predictions.
Moderator Response:[JH] You seem to be more interested in playing "Gotcha" games with other commentors than engaging in a civil discussion of the science. As far as I am concerned, playing Gotcha is sloganeering which is banned by the SkS Comments Policy. Please cease and desist. If you do not, your posts will be summarily deleted.
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Bob Loblaw at 05:08 AM on 16 April 2013Antarctica is gaining ice
Kevin@174
Why is it that you stop reading/processing information as soon as you see something that you think supports your predtermined conclusons?
The passage you quote talks about snowfall and melt. It does not talk about ice flow. Mass balance of a marine-terminating glacier depends on more than just snowfall and melt. Thre is not enough information in that quoted passage to support your conclusion that Antarctic Land Ice will increase.
Until you do a complete mass balance calculation, you will continue to arrive and unspported (and/or unsupportable) conclusions.
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Bob Lacatena at 05:02 AM on 16 April 2013Antarctica is gaining ice
Kevin,
The bottom line is that you don't understand what it is that you are reading, and you are projecting that ignorance onto everyone else.
The Antarctic Ice Sheet is a complex environment, consisting of an interaction between rising temperatures, increasing precipitation, ice at extreme altitude (hence always below freezing), ice just above sea level (affected by air temperature), ice below sea level (affected by the warming water beneath), and gravity (which threatens to flow ice gains in the interior quickly down into the ocean, where it will melt). This now is recognized to be further complicated by the freshening of the surrounding ocean water due to the melt, changes in currents, etc.
And out of all of this, your takeaway is that the IPCC reports have some comments that you can cherry-pick to raise false doubt.
This is why the term "denier" is used at all.
Bottom line: You don't understand what you are reading, and you are going out of your way to create an illusion of doubt and incompetence, because you can't come to terms with the idea that your actions (and lack of action) are going to affect future generations, and you maybe will need to demonstrate more responsibility (and yes, maybe a little sacrifice) when you don't want to.
I am always appalled at the way my generation lauds The Greatest Generation for the great sacrifices they were repeatedly able to make... and yet they won't surrender their multi-ton SUVs until you pry them from their baked, dead hands.
Moderator Response:[JH] Please tone down the judgemental rhetoric. We simply do not know whether Kevin posts to cause mischief, or is honestly trying to understand a very complex subject matter. Kevin has also been advised to tone down his posts.
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Kevin8233 at 04:46 AM on 16 April 2013Antarctica is gaining ice
From the Scenarios of future change, 16.1.4 of the Third assessment report...
Models predict that land areas in the Arctic will receive substantially increased snowfall in winter and that the climate will be markedly warmer. Summer could be much warmer and wetter than present. The climate over the Arctic Ocean does not change as dramatically, but it will become warmer and wetter by 2080. For the Antarctic continent, the models tend to predict more snow in winter and summer. Although temperatures are forecast to increase by 0.5°C, there will be little impact on melt because they will remain well below freezing, except in limited coastal localities. The Southern Ocean warms least, especially in summer. Precipitation increases by as much as 20%, so there will be more freshwater input to the ocean surface. This chapter also refers to other climate models. Some are equilibrium models for the atmosphere only; others are transient, coupled atmosphere-ocean models. Some deal with aerosols and other do not. In polar regions there can be large differences in predictions, depending on the model chosen, although most predict large changes in climate over the next 100 years. Assessments of impacts will vary, depending on the climate model chosen. This should be kept in mind in assessing the impacts described in this chapter.
And yes, there is extensive uncertainty in this prediction, as some processes are not understood entirely.
Bottom line though, the latest prediction by the IPCC has Antartica Land Ice gaining as temps increase.
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Composer99 at 04:37 AM on 16 April 2013Antarctica is gaining ice
(Clarification to my post #172: it does not include any comments posted by Kevin in #171.)
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Composer99 at 04:36 AM on 16 April 2013Antarctica is gaining ice
I would also add that the passage cited by Kevin is not a prediction (contrary to his assertion), but a description of observed contemporary ice sheet behaviour, of Antarctica as a whole, up until the publication of FAR, while the discussion in the OP has to do with observed (not predicted) behaviour in the last decade (as per the publication dates of papers cited), so there is little surprise that the OP mentions more ice mass loss than FAR.
Finally, scaddenp mentioned the Third Assessment Report, in 2001, whose descriptions of observed behaviour in Antarctica would differ from the observed behaviour described in the 1990 FAR and also from the behaviour discussed in the present day.
Kevin, was it your intent to suggest that:
- There is something illegitimate about having a superior understanding of ice sheet behaviours after 20+ years of further study, such that predictions are more refined and observations more robust and less uncertain?
- There is something illegitimate about conditions changing such that what was the case up until 1990 (net balance or even land ice mass gain) has changed by the present day (net land ice mass loss)?
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Kevin8233 at 04:28 AM on 16 April 2013Antarctica is gaining ice
I could not find an actual prediction regarding antartic ice sheet levels in the fourth assessment (they do discuss the peninsula). They do, however, in the openning comments address the projections of the TAR as indicated below.
Key regional projections highlighted in the TAR
Increased melting of Arctic glaciers and the Greenland ice sheet, but thickening of the Antarctic ice sheet due to increased precipitation, were projected.
It is interesting that this is not sea ice they are talking about, but land ice.
So Sphaerica, has the science advanced enough for the fourth (actually third) assessment? If not, then I guess they have no business commenting on anything. The Third assessment was saying that snow gains more than covers coastal losses.
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Rob Honeycutt at 04:21 AM on 16 April 2013Antarctica is gaining ice
Yup. Just reading through it. It's all relative to sea level changes. What's particularly interesting to me (and encouraging) is that the report isn't overstating their confidence levels. They're using very careful wording to accurately convey what they knew at that time. If you read on, they're also talking about the instability of the WAIS. Clearly, you can be adding ice (snow) in the interior but also be losing ice through ablation. And that is what I've always read in the literature. I'm not seeing the FAR chap 9 disagreeing with this at all.
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