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KK Tung at 07:59 AM on 18 April 2013The anthropogenic global warming rate: Is it steady for the last 100 years?
So that I don't appear as impolite for not answering questions on the AMO, just want to say that I had submitted my second post on Tuesday, and it is awaiting its turn at SkS.
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Global Warming is Accelerating, but it's Still Groundhog Day at the Daily Mail
Kayell - "...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)."
That would be incorrect - see Levitus et al 2012, Fig. 1:
The vertical bars show 2x the standard error (SE) of the pentadal mean, working from ARGO and the XBT data that have sufficient metadata for depth corrections, with extrapolation via observed anomaly correlations. The lower section of the chart shows the global percentage of 1-degree squares that have at least four pentadal data points for each year.
The fact that some data is less certain that others does not justify claiming that data doesn't exist. If you feel Levitus et al have made mistakes in their SE calculations, please point them out or give references you feel support such claims - but again, you can't justify claiming that data isn't available.
And note that the deep ocean warming is, indeed, unprecedented in the data we have available.
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Tom Dayton at 03:57 AM on 18 April 2013Global Warming is Accelerating, but it's Still Groundhog Day at the Daily Mail
Awesome graphic! I will use it often!
In this paragraph Rob made a point that in my opinion is vastly underpublicized and appreciated:
"But why don't observed temperatures follow the centreline of the projections? The darker orange-shaded area represents the (25%-75%) average of the model runs - when they all have been aggregated together. If the Earth was able to run the same year over-and-over-again, like the models, it would probably do the same. But the Earth only gets one shot at this. One roll of the dice. So rather than being smoothed out - like the average of all the climate model runs - actual surface temperatures yoyo up-and-down - exhibiting large year-to-year variability. As they would if only one climate model run was carried out."
When Tamino pointed this out on Dec. 20, 2012, he regraphed the actual temperature trend so its 1990 starting point was vertically at the mean trend as of 1990, instead of at the 1990 point mean. Scroll to the last three graphs of his post. Maybe somebody could combine those graphs into an animated Skeptical Science graph....
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MarkR at 23:46 PM on 17 April 2013Global Warming is Accelerating, but it's Still Groundhog Day at the Daily Mail
Kayell @ 1,
The total energy balance of the Earth is positive, thanks mostly to humans. The extra CO2 is continuing to heat the atmosphere and the surface as usual, keeping us warmer than we'd be otherwise.
At the same time, we've recently seen much more common La Ninas (Meehl et al 2011) and changing wind patterns (Balmaseda et al 2013) which have shunted heat to the deeper ocean.
This sort of thing happens naturally, but without human CO2 to warm the atmosphere/surface then we can be pretty sure that temperatures would have gone lower without human activity.
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julesdingle at 23:39 PM on 17 April 2013Global Warming is Accelerating, but it's Still Groundhog Day at the Daily Mail
Is AGW affecting La Nina years? Perhaps someone can be of help- first of all correct me where I am wrong.
La Nina is when the oceans warm and the air cools- switching to a cooling ocean and heat transfering to atmosphere.
The cycle is now in more la Nina or neutral stage.
In a El Nino cycle that heat will be dumped into the atmosphere increasing temperatures back to those predicted [I know models are not predictions just tools!]
Clearly any fool can see that ocean heat is melting arctic ice [except blind fools]
My question- is a warming ocean preventing cooling?
Are there any papers that suggest that the lack of El Nino activity is related to the amount of heat being absorbed?
Outcomes- will the next ocean cooling cycle be big like 1998 or bigger? or are we likely to see atmospheric temperatures 'stabilise' in a slow increase but for the energy to be transfered into weather like storms/drought/ general weather disruption?
thanks J
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Composer99 at 23:36 PM on 17 April 2013Global Warming is Accelerating, but it's Still Groundhog Day at the Daily Mail
My congratulations to Rob or whomever created the animated gif showing the difference between the reality of global warming and how pseudoskeptics present it. It really highlights the intellectual paucity of the pseudoskeptic case in a clear, visually compelling way.
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K.a.r.S.t.e.N at 22:22 PM on 17 April 2013The anthropogenic global warming rate: Is it steady for the last 100 years?
Just as a brief addition to what's already been said. As MA Rodger has mentioned, the anthropogenic forcing time serie published in Skeie et al. (2011) shows strong multidecadal variability (Fig.1c). I consider it superior to any other forcing estimate. Given the highly non-variable nature of the imposed forcing, your assumption of internal variability breaks down. To illustrate the temporal coincidence, I plotted the surface temperature of North America, Europe (GISS), and North Atlantic(HadSST2) vs. anthropogenic and volcanic sulfate forcing (plus OHC):
For the chosen domains see here. North America and North Atlantic nicely agree. Note the perfect agreement between sulfate forcing and temperatures. It is certainly not just coincidence, as the same (short term) response can be seen for volcanic forcing. Given the nature of the circulation (jetstream blowing from west to east), the ocean just follows the atmospheric temperatures, as Tamino pointed out at his blog. On top of that, land temperatures seem to lead the AMO as Tamino also pointed out. If you subtract the GISS NH from North Atlantic temperatures, you get this:
This is the true AMO signal which remains.
The one thing I found really surprising in your paper was how easily you rejected Booth et al. (2012). Overestimation of the aerosol forcing (as nicely argued from Zhang et al. (2013)) does not make it go away. If you take the strong volcanic activity around 1815-1840 and 1880-1910 together with the anthropogenic sulfate forcing between 1950-1970, you can explain three distinct cycles. You mentioned another one between 1660-1680. Makes it four cyles. The frequency coincides with the spectral peaks between 60-90 years. No surprise that you just found that (as others did before). May very well be pure pseudo-oscillatory behavior.
Finally, how do we know that the sulfate forcing is real? We have measured it!
(1) The downwelling SW (clear sky) radiation was reduced, known as global dimming and later brightening (see Skeie (2011) or Wild (2012)).
(2) The anthropogenic sulfate aerosols are clearly identifiable even in Arctic ice cores (graph taken from Tamino). It must have affected NH temperatures!
I wonder why you carefully omitted the discussion of these aspects in your paper? To be honest, I personally can't see how your paper contributes in any way to advance our understanding. Given the aforementioned shortcomings, I consider your paper not only a pointless curve-fitting exercise which does not tell me anything about proper attribution, I consider it to be simply wrong. Perhaps you can offer some more compelling evidence in your second post ... which I am looking forward to. I finish with two papers which I found much more convincing: Ottera et al. (2010) and Terray (2012). They both made a nice effort to disentangle the different drivers at play.
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Tristan at 21:38 PM on 17 April 2013Further Comments on The Economist's Take on Climate Sensitivity
Thanks Doug.
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CBDunkerson at 21:25 PM on 17 April 2013Antarctica is gaining ice
John, I have to question the logic of that Steig study reported in CSM. Basically, they looked at ice cores from the peninsula and high on the WAIS. The cores from the peninsula showed recent melting at a rate 10 times greater than the highest previous values while the cores from the WAIS showed melting at rates comparable to the highest previous values. From this they concluded that the peninsula is melting due to global warming and the WAIS due to natural variability.
The problem, as I see it, is that the majority of the WAIS ice loss is not occuring at the far inland locations where they gathered the ice cores. The WAIS (and the EAIS for that matter) are losing ice from the edges of the continent. Ice loss far inland may indeed be largely due to natural variability... but that is a tiny percentage of total ice loss. Much more is being lost at the edges of the ice sheet as warmer water (from global warming) causes ice shelves to break up and land ice calves into the oceans at a faster rate.
Essentially, the Steig study seems to be the equivalent of attempting to measure global warming by looking only at mid-day temperatures along the equator... the data which should show the least greenhouse warming signature. They failed to find a global warming signature in the WAIS ice loss because they only looked at the ice which is least likely to be impacted by global warming. If they had looked at ice loss around the edges of the ice sheet, where the vast majority of it is actually occurring, they should have gotten very different results.
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CBDunkerson at 21:07 PM on 17 April 2013Global Warming is Accelerating, but it's Still Groundhog Day at the Daily Mail
Ray wrote: "This variable reporting..."
I don't see the variation. Both of the following are true;
- Most ocean warming has taken place in the top 700 meters of the ocean.
- There has been unusually high warming of the oceans below 700 meters.
These two findings are in no way contradictory of each other. Warming below 700 meters has gone up significantly... but is still less than warming down to 700 meters.
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Rob Painting at 20:49 PM on 17 April 2013Global Warming is Accelerating, but it's Still Groundhog Day at the Daily Mail
Ray- as stated on the thread on the Guermas (2013) paper, I have not read that paper. Exactly why they disregard the warming of the deep ocean is not clear. Perhaps worth looking into at some point, but differing opinions on cutting edge research is simply par for the course. They can't both be right, so one idea will fall by the wayside.
Yes, the bulk of the warming occurs in the upper ocean. My apologies if that wasn't clear. The important feature of table 1 is that the very recent deep ocean warming is unprecedented in the admittedly short period of observations (the last 50 years - see Levitus [2012]). This has obvious implications, as discussed in the post, because it is a large part of the reason for the acceleration in ocean heating.
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Ray at 19:48 PM on 17 April 2013Global Warming is Accelerating, but it's Still Groundhog Day at the Daily Mail
Here you say "A number of scientific publications, (Von Shuckmann & Le Traon [2011], Levitus [2012], Nuccitelli [2012] & Balmaseda [2013]) have shown the oceans, and notably the deep oceans (depths below 700 metres), have warmed." Yet in your post on April 15th you wrote "Interestingly, Guemas et al. find that most of the recent slowed surface warming can be attributed not to the accelerated deep ocean warming, but to the accumulation of heat in the relatively shallow oceans (to 700 meters). They note that their results are consistent with Loeb (2012), in that most of the global energy imbalance is absorbed by the upper 700 meters of oceans, although the deeper ocean heat accumulation cannot be neglected"
Looking at the table from Balmaseda (2013) it looks as if the warming of upper 700 metres is very significantly more than warming below 700 metres
This variable reporting is very confusing and does lead to scepticism that climate scientists really understand what is happeing in the oceans
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scaddenp at 19:22 PM on 17 April 2013Global Warming is Accelerating, but it's Still Groundhog Day at the Daily Mail
Kayell, if you want the textbook outline of the thermodynamics of GHG heating of ocean, then please see the rather exhaustive series at Science of Doom, that begins with this.
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Dikran Marsupial at 18:58 PM on 17 April 2013Global Warming is Accelerating, but it's Still Groundhog Day at the Daily Mail
Kayell - If you think there is an inconsistency in the chain of reasoning, then point it out explicitly, stating your assumptions. It is generally rather more likely that you are labouring under some misaprehension regarding the science than that the scientists whose work is reported here are wrong. It will be much easier to answer your concerns if you actually articulate your own line of reasoning, so we can see why you think there is an inconsistency. Also asking vague questions as you have done, without stating your own position, gives the impression of trolling, which I trust is not your intention.
Perhaps this RealClimate article may be of some help: http://www.realclimate.org/index.php/archives/2006/09/why-greenhouse-gases-heat-the-ocean/
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MA Rodger at 18:48 PM on 17 April 2013Global Warming is Accelerating, but it's Still Groundhog Day at the Daily Mail
The post doesn't make clear why Rose is off again on his tour of Punxsutawny. (It's probably not so relevant as Rose usually doesn't need an excuse.) He is reacting to a Parliamentary select committee.
"The official watchdog that advises the Government on greenhouse gas emissions targets has launched an astonishing attack on The Mail on Sunday – for accurately reporting that alarming predictions of global warming are wrong."
Yet his latest article isn't quite Groundhog Day. He demonstrates the veracity of his case by mentioning the Economist article (which isn't that supportive of denialist twits) and two denialist twits who entirely agree with him and the Economist article again.
If you like a bit of fun, it should be noted that Rose has himself now entered the climate prediction business by telling the sad fools who read the Daily Rail in his previous article (on the graph - it is absent on the version use for this latest article) that HadCRUT4 is "about to crash out" of the shaded zone. Thus he appears to be predicting an annual HadCRUT4 anomaly for 2013 (the graph is of such data) of less than 4.5 °C.
Kayell @1.
The specific mechanism is the way those devious heat fluxes always seem to flow from hot places to cold places.
Here is a question or two for you to mull over. With the average surface temperature of the planet some 14 °C (and rising) and the Earth's core over 5000 °C, what is the average temperature of the world's ocean waters? Remember here that 90% of that is usually described as "deep", a useful term to include if you consider a web search would be helpful. And why is that?
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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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