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Glenn Tamblyn at 13:56 PM on 16 April 2015Global warming hiatus explained and it's not good news
Peter.
From the first link scadenp gave you
"To a certain degree, Eastern Boundary Current (EBC) ecosystems are similar: Cold bottom water from moderate depths, rich in nutrients, is transported to the euphotic zone by a combination of trade winds, Coriolis force and Ekman transport. The resultant high primary production fuels a rich secondary production in the upper pelagic and nearshore zones, but where O2 exchange is restricted, it creates oxygen minimum zones (OMZs) at shelf and upper slope (Humboldt and Benguela Current) or slope depths (California Current). These hypoxic zones host a specifically adapted, small macro- and meiofauna together with giant sulphur bacteria that use nitrate to oxydise H2S"
So, "This can only occur, in this area remote from human influence, from undersea volcanic activity."
Nope, you assumption is wrong. There is another major source, anaerobic sulphur bacteria that thrive in anoxic conditions!
Volcanic activity isn't the only source of H2S! Simply assuming that it is is sloppy reasoning. If ou want to evaluate an idea you need to consider geological evidence, oceanographic/hydrological and fluid mechanics evidence, and biological evidence.
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And..."Could it be that warmer water rises?"
Only if it is warmer than the water above it! If cold water is warmed but not enough to make it warmer than the water above, it doesn't rise. Example. If water at 4 Deg C is warmed to 6 deg C it can't rise if the water above it is 20 deg C.
So how much warming?
Peter, unquantitative arguments are worthless.
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Infopath at 11:43 AM on 16 April 2015Global warming hiatus explained and it's not good news
Peter Carson@30: "(Wasn't it Einstein who said all things are relative?)"
Uh... no, I don't think he did. Do you have a reference/link?
(Sorry, OT but couldn't resist (feel free to delete).)
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rockytom at 07:03 AM on 16 April 2015New textbook on climate science and climate denial
To #19 Bappleby13
I have tried to get information from our publisher on specific adoptions but have not yet succeeded. Springer says they can provide me with statistics from each region (state?) but not individual institutions. I find this difficult to believe. I will forward a copy of your kind offer and approach them in a different way in hopes of receiving the pertinent information. If you have a list of the "distracting little errors and duplications" I would appreciate receiving it at rockytom09@gmail.com. We are in the process of preparing for a 2nd edition for sometime in the near future, as soon as John and I complete Volume 2, "Earth's Climate History" and John finishes his MOOC and Ph.D.
Thank you for your submittal and offer. Tom
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Tristan at 06:55 AM on 16 April 2015Human CO2 is a tiny % of CO2 emissions
toolate: As the mod's suggested link points out, respiration doesn't really have a net impact. The domesticated ruminant (eg cows, sheep, goats) population is another matter though - entric fermentation of plant matter in their stomachs generates methane, a potent GHG.
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Mal Adapted at 06:13 AM on 16 April 2015Global warming hiatus explained and it's not good news
Peter Carson: "Oh! And I am a scientist. What are you doing here?"
Peter, what evidence can you give us that you are a scientist, so we can judge your claim for ourselves? Your comments here don't evince advanced scientific training, nor the inclination to approach the topic of undersea volcanic heat flux as a scientist would.
A person whose scientific ideas have passed peer review and been published in appropriate refereed venues can be considered a scientist. I searched Google Scholar for publications by "Peter Carson" or "Carson, Peter", but the only hits were published in medical journals, on the topic of heart failure. Was that you? If not, please provide citations to your peer-reviewed scientific publications.
In any case, we will draw our own conclusions about whether you're a scientist or not. BTW, have you heard of the Dunning-Kruger effect?
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toolate at 04:46 AM on 16 April 2015Human CO2 is a tiny % of CO2 emissions
In terms of identifying MM Co2 emissions, how should the CO2 exhaled by the planet's population be counted? Should CO2 emissions resulting from farming, crop or livestock, be counted as MM or natural? Same question for CO2 generated from natural decomposition on our world's landfills. Human waste, treated in sewage plants and piped into rivers and oceans, generates CO2 - natural or anthropogenic? Should the definition of MM Co2 be limited to only that which exits a tail pipe or smoke stack? Even if all CO2 emissions from burning fosil fules could be sharply curtaild or eliminated through sequestration, each year there are more people on the planet, and with each year life expectancey is longer. We all need to eat and breath and as a consequence of life need excrete waste. Surely all sources of MM Co2 should be considered and counted in an appropriate way.
Moderator Response:[TD] See "Does Breathing Contribute to CO2 Buildup in the Atmosphere?" It has both Basic and Intermediate tabbed panes.
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DSL at 02:52 AM on 16 April 2015Global warming hiatus explained and it's not good news
Peter: "ARGO is unlikely to show heating. I think the floats only take a reading every 30 mins so that they are likely to miss an actual eruption; the warm water would likely just float up past them without being recorded. They’d also have to be situated over the correct position."
This is the most ridiculous thing I've read in months. Volcanic action that produces enough heat content to warm the El Nino 3/3.4 regions for months just magically slips by dozens of Argo floats. This is what happens when a pet theory is forcefully driven through the actual data: Bizarro Physics. -
PhilippeChantreau at 00:45 AM on 16 April 2015Global warming hiatus explained and it's not good news
Scaddenp presents numerous references that none of your arguments address Peter. I'm sorry but you're not being any more convincing by repeating the same arguments without any more backup than before.
I'm not sure what you're trying to say about references. You claimed to be a scientist. Scientists refer to the scientific litterature. This site is about science and the whole premise to its existence is to bring up what real science says about a subject. The comment policy of the site indicates that claims should be backed up by scientific references. Peer-review is a minimum standard, there is no reson to go below that. "Sources accesssible to the general reader" can be anything and everything, that's no basis to conduct a discussion about science.
The H2S has been shown to be of organic origin. The entire ecosystem suffers when cold water upwelling stops, and everything below the fish in the food web starts dying. The fish eventually die too but by then H2S from the other organisms that have died before is noticeable.
No seismic activity that would be caused by increasing volcanism has been observed around the events.
Birds that rely on anchovies for 80% of their diet are going to continue looking for anchovy at sea until they no longer can. Birds dying of exhaustion or starvation at sea is really not an unusual occurrence a all. Sea birds that are hungry do not stay on shore, they go look for food. One of Scaddenp references above mentions that bird die-offs have been observed during El-Nino events as far California, Oregon, Alaska and the Bering Sea. Large scale weather events can and do kill birds.
At this point, there is a lot more evidence against your theory than there is in its favor.
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funglestrumpet at 23:42 PM on 15 April 2015Andy Lacis responds to Steve Koonin
This discussion is way above my level, but, having tried to follow it, I cannot say that I have seen the influence of gravity in anyone's comments - perhaps I missed it. Specifically, what occurs to me is that as ice sheets melt, so their gravity diminishes leading to a fall in sea-level around them. Could this be important with the WAIS? As it melts, so the sea-level falls and thus places the fracture point under more bending stress, which in turn might complete the fracture, leaving it free to float off (though grind off is probably more correct) to deeper waters?
Probably unimportant, but felt the need to raise it just in case. ('Out of the mouths of babes and innocents' and all that!)
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ranyl at 21:39 PM on 15 April 2015Andy Lacis responds to Steve Koonin
Hi Glenn,
However despite all that NH ice weren't the meltwater pulses from the last deglaciation primarily from the SH?
And this quote is interesting,
"Our new RSL chronology permits the first robust calculation of rates of relative sea-level change throughout the past 150,000 years (Fig. 3c). This reveals that rates of sea-level rise reached at least 1.2mper century during all major phases of ice-volume reduction, and were typically up to 0.7m per century (possibly higher, given the smoothing in our method) when sea-level exceeded 0m during the LIG (Fig. 3c); the latter is consistent with independent estimates21,22."
Grant K.M. et al (2012) "Rapid coupling between ice volume and polar temperature over the past 150,000 years"
And the top of WAIS is melting in a non linear fashion
"The nonlinearity of melt observed in the JRI ice-core record also highlights the particular vulnerability of areas in the polar regions where daily maximum temperatures in summer are close to 0 C and/or where summer isotherms are widely spaced, such as along the east and west coasts of the Antarctic Peninsula (Supplementary Fig. S3). In these places even modest future increases in mean atmospheric temperature could translate into rapid increases in the intensity of summer melt and in the poleward extension of areas where glaciers and ice shelves are undergoing decay caused by atmospheric-driven melting."
Abram N.J et al (2013) Acceleration of snow melt in an Antarctic Peninsula ice core during the twentieth century, Nature Geoscience
“The need to improve upon the uncertainty in the LIG ESL estimates is best seen in terms of its consequences on melting from both Greenland and Antarctica during the LIG. Current modelling and data-based estimates converge on a 2- to 4-m contribution to ESL from Greenland and on a maximum contribution of +3.3 m from West Antarctica (32). Thus, the lower limit estimate of the peak LIG ESL (+5.5 m) is consistent with such contributions from both Greenland and West
Antarctica, but the upper limit (+9 m) implies additional melt-water contribution from adjacent sectors in East Antarctica.”
A. Dutton and K. Lambeck (2012) Ice Volume and Sea Level During the Last Interglacial, Science
“However, the retreat of these southernmost terrestrial ice margins within centuries of an increase in boreal summer insolation of only 1–2 W m–2 (Fig. 5a) suggests that terrestrial ice margins near their climatic limit are responsive to small changes in radiative forcing.”
“However, the final collapse of the marine portion of the Laurentide Ice Sheet at ~8.2 kyr ago occurred in less than 130 years and raised eustatic sea level 0.8–2.2 m75, which is a timescale of more importance to global society”
Anders E. Carlson and Kelsey Winsor (2012), Northern Hemisphere ice-sheet responses to past climate warming, Nat. Geoscience
So I agree Hansen is hopefully being too bold, as I said already, however with the Weddell Icesheet under threat as sea levelsrise and Southern Ocean winds progress Sotuhwards, and the below seabed portions of EAIS, mean that 1-2m by 2100 is lookingmore liley especially when considering the amount of extra heat into the whole system, far more than in the LIG,whose overall global additional wattage input was due to GHG mainly.
We passed 300ppm a long time ago, so it is clear that to melt ice takes time indeed, however that isn't that reassuring as since 1990 ice melt has accelerated markedly in all areas and the heatinput into the oceans in the last 10 years alone is remarkable compared to previous melt periods and for melting seabed icesheets that must count, especialy as West PAC waters find their way to the Antartica quite quickly and that is warming quite rapidly.
Further sea level isn't even, and the East Coast of America gets more than its fair share, 1m globally about 2m EUSA.
Put it this way, real estate investment in New York isn't a long term investment option on solid ground I'd venture.
It si weird how the early Pliocene was 3-5C warmer at 350-400ppm (0.25 to 0.42 of a doubling), considering the CS of only 3C for a doubling or 560ppm, hhhmm, oh yeah that is right the CS for full long term equilibrium is double the CS reported by the IPCC forgot about that, it makes more sense now, but still if 350ppm (and that looks more likely now) then still need long term CS of at least 12C if the 3C lower estimate is true, even if it was 2C (some studies say 2C, mainly Hansen as by the by, just make melting more susceptible to temperature rise as sea elvels still 20-25m higher), you still need a long term equilibrium CS of 8C. And the sun was cooler a little bit only a very small bit, all the orbitial parameters actually add zero to the global overall heat input and the continents were close enough not to matter that much, so not much comfort in loooking for other heat sources.
The NH did have a totally different temperature profile though, interesting, I ownder if the Hadley cell system was different back then due to polar equatorial temperature differential being so much lower, as that would definately affect ice melt in Greenland, keeping in mind there was no GIS then.
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Glenn Tamblyn at 19:27 PM on 15 April 2015Andy Lacis responds to Steve Koonin
Ranyl
I tend to agree with Tom that Hansen's view is at the extremes on a single century scale - on multi-century all bets are off. When the high rates of melt occurred we had major ice sheets in Canada/US, Scandinavia, Northern Europe and western Russia. Also southern South America and the Australian highlands. Possibly also areas of the Arctic sea ice had become like West Antarctica, grounded on the sea floor and projecting significantly above sea level. So a much larger area from which melt could occur.
To produce similar melt rates today we would need much higher temperatures to trigger much higher melt rates per km2 since there are so much less km2 available.
That said, I recall a paper published a couple of years ago - can't find it now - looking at fossil beaches in Western Australia from the last Interglacial - the Eemian. Sea levels were reported as being around 5 meters higher than now for much of the interglacial then near the end they spiked higher to more like 9-10 meters higher.
This suggests a sudden major ice collapse with the WAIS the likely culprit.
It is interesting to look at the ice core data for temperature history during the Eemian. They spiked higher than today but only for a short period. Perhaps some major disruption in southern ocean currents around the WAIS triggered an ice collapse and the Albedo change triggered a spike in warming. Then the currents reverted and it was all reversed.
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RedBaron at 19:22 PM on 15 April 2015CO2 limits won't cool the planet
Of course CO2 limits won't cool the planet. You even admit that yourself. The problem however is stated in the form of a false dichotomy. Mitigation in order to work needs every little bit from every possible technology available. The largest of course, by many orders of magnitude, is the soil sink potential. Next comes alternative energy and then conservation. Tree growth and chemical scrubbing are barely a blip on the screen. Not saying we shouldn't try them too, but the net effects are minimal. Soil on the other hand is depleted of carbon, more carbon than is in excess in the air. The technologies to get that carbon back in the soil are very well established agricultural science methodologies and already beginning to be practised in the field by ordinary farmers and ranchers. We just have get serious and do it.
https://www.youtube.com/watch?v=9yPjoh9YJMk
I know that's just a Youtube vid, but that speaker is one of several USDA NRCS case studies.
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ranyl at 18:54 PM on 15 April 2015Andy Lacis responds to Steve Koonin
Well Tom,
I never said I agreed with Hansen merely pointed out why he felt 5m was possible, to add to that he bases his estimates on thepotential from previous melt rates and the doubling time of the acceleration of the melt already being seen in both icesheets.
Further can you name one ice sheet expert who opinion isn't in some way curtailed by alarmist branding!
There are many factors involved, although the 6-9m from the LIG wasn't all from the NH therefore the same forcings that helped loss of the Southern Greenland Ice sheet also would have been making the SH colder yet, atleast half of the melt came from there, implying that the higher CO2 level of the LIG at ~300ppm certainly helped some.
Then there all the new findings, such as the ehat transfer into the centreand base of the ice sheet due to surface melt heat advection, which those experts wouldn't have been taking into account,
Phillips T et al, (2013) Evaluation of cryo-hydrologic warming as an explanation for increased ice velocities in the wet snow zone, Sermeq Avannarleq, West Greenland , Journal of Geophysical Research
“The sun melts ice into water at the surface, and that water then flows into the ice sheet carrying a tremendous amount of latent energy,” said William Colgan, a coauthor and CIRES adjunct research associate. “The latent energy then heats the ice.”
“It could imply that ice sheets can discharge ice into the ocean far more rapidly than currently estimated,” Phillips said. “It also means that the glaciers are not finished accelerating and may continue to accelerate for a while. As the area experiencing melt expands inland, the acceleration may be observed farther inland.”
“Previous studies estimated that it would take centuries to millennia for new climates to increase the temperature deep within ice sheets. But when the influence of meltwater is considered, warming can occur within decades and, thus, produce rapid accelerations.”
“Traditionally, latent energy has been considered a relatively unimportant factor, but most glaciers are now receiving far more meltwater than they used to and are increasing in temperature faster than previously imagined,” Colgan said. “The chunk of butter known as the Greenland Ice Sheet may be softening a lot faster than we previously thought possible.”
Then there is also the new evidence of the Pine Island glacier having gone into irreversible melt and it also looks like the Thwaites and a few others will follow suit.
And from the Jevrejeva paper, “The AR5 addresses this issue by suggesting that 'only the collapse of the marine-based sectors of the Antarctic ice sheet, if initiated, could cause sea level to rise substantially above the likely range during the 21st century”
So the question definately is rate, and I agree 5m by Hansen is a definitive high end, but previously observed (with more icesheets but land based ones), and the by 2100 somewhere between 1-2m seems more likely, although the accelerating rates being observed for icesheet melting is concerning for it can only accelerate further, and that acceleration as it lowers icesheet height and more seabed icesheets get undermined beyond critical melt back, can only accelrate again due to dynamic mechanisms fedding back on themselves.
And then waht sea level rise by 2150 as rates keep accelerating and then by 2200?? Rome been arround several 1000's por years as has London.
And as CO2 isn't going anywhere for a very long time it is essentail to realise that at 350ppm -400ppm we are committed to an early Pliocene climate, whatever efforts are made to stop emissions, only taking CO2 out of the atmosphere can change that, and to take 50ppm out is a collossal task indeed, and we still progress at top rates, and forest fires, permafrost melt and soil respirations are all going to add to the burden.
Finally what does 1-2m mean?
Well moving New York for a starter for ten!
If we get 4-5m by 2200, then that is most of Florida, Bangladesh, Holland and Miami already floods at high tides!
Moderator Response:[DB] Shortened and hyperlinked URL that was breaking page formatting.
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scaddenp at 18:42 PM on 15 April 2015Global warming hiatus explained and it's not good news
Peter, I would then also ask you back your arguments from the peer-reviewed literature.
Tom has already pointed you to carefully calculated example on heat production. Note that OHC is change from baseline, so to blame global warming on volcanic activity, then you need to have an increase in heat flow through 20 century above that of heat production in previous centuries. Furthermore, conduction and convection are continuous processes - you dont get instantaneous movement of heat except from ejecta to surface and that could only account for a minisule amount of the heat produced. You are going to have to that huge volume of material necessary for the heat to be as ejecta! If you postulate underwater volcanism then you predict convective cells based ocean ridges. No such thing is observed. The TAO should also see this and it is most certainly in the right position since designed to observe El Nino.
Sulphur isotopes cant be used for dating as far as I am aware, but for fractionation try here. Furthermore organic hydrogen would contain tritium and inorganic none.
Current theory is not descriptive - it is present in dynamic models. However, the process is chaotic and thus not predictable in the short term. And yes, I do have confidence in physical models that reproduce the character of El nino versus a theory with no plausable physical basis.
As to Walker, the seismic activity does not equal volcanism and in fact, the correlation is the other way round - El nino triggering faulting from plate flexure. Eg see here or here or here.
What is your source for cause of sea bird deaths? This reference and this suggest resource loss. For a scientific discussion, please stick to peer-reviewed sources.
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Peter Carson at 16:57 PM on 15 April 2015Global warming hiatus explained and it's not good news
My 36 applies to @33 PhilippeChantreau
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Peter Carson at 16:09 PM on 15 April 2015Global warming hiatus explained and it's not good news
1. How does cold water upwell?
2. As for my evidence? The observations (re fish deaths etc have been reported widely. I’ve found no difficulty using Google or Encyclopaedia Britannica. (I’m old-school to still prefer paper! Anyway, I prefer to use sources that are readily available to all and which may be more accessible to the general reader such as may be on sites such as this. I’m no snob!)
Anyway, H2S does have its distinctive odour, noticed by the fishermen before decomposition sets in. They are in the area all the time so they’d notice.
Sea birds are dead at sea – they were active - not on the land where their nests are and where one would expect them to die if weakened by lack of food. They are poisoned at sea.
3. You’ll notice I’ve referenced Walker in my reply to scanddenp, in support of seismicity. When I spoke with Walker a few years ago, he seemed rather worn down by the attacks on him. I don’t blame him! (I’ve also corresponded with him by emails.) I reached his conclusion, but using thermodynamics, in the mid 90s but also had that publication discarded.
Moderator Response:[Rob P] - the answer to No.1 is Ekman suction. The large-scale areas of upwelling are on the equator and the eastern side of the ocean basins, such as the Pacific coasts of North & South America. Surface water is displaced by the drag of the wind on the uppermost layers. Persistent winds cause seawater from the deep to be drawn up to the surface to replace the water that has been 'pushed' away.
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Peter Carson at 15:30 PM on 15 April 2015Global warming hiatus explained and it's not good news
Thanks scanddenp, in that you do provide scientific back-up to your arguments.
1. Calculation: Annually but using the low figure of only using East Pacific Rise and discounting the extra effect of Galapagos Ridge.
Height (2 km) x length (say 1,000 km) x Width (0.1 m) = 0.2 cu km
EN happens one year in five on average. This gives 1 cu.km per thousand km of Ridges in the vicinity.
2. I don’t know of anySulphurisotope that could be used for dating or origin purposes. Please inform.
3. Your “1/ El Nino should be correlated with change in undersea volcanic productivity. None that I can see.”
Try Daniel A Walker (a geophysicist – I’ve spoken with him some years ago) Eos vol 76, 1995 p 33 to 36. “More evidence indicates link between El Nino and seismicity”.
[Come in Spinner!]
4. You seem confident in the current “theory” for EN. It should match data rather well - it’s not actually a theory but a description of events! It has no predictive capabilities whatsoever. For example, how does it explain how El Nino got its name, ie occurring near Xmas? It can’t.
(I can! - but you’ll have to wait for me to put it onto my site.)
What causes theWalkercirculation to weaken? Why do the tropical westward winds drop preceding an EN, especially since the west now has a build-up of warm water pushed there? That should increase these winds!
5. ARGO is unlikely to show heating. I think the floats only take a reading every 30 mins so that they are likely to miss an actual eruption; the warm water would likely just float up past them without being recorded. They’d also have to be situated over the correct position.
Heat from volcanic activity on the bottom will not stay there waiting for its temperature to be taken but will rise.
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scaddenp at 14:52 PM on 15 April 2015Global warming hiatus explained and it's not good news
Interesting Phillipe. Looks like hypothesis was looked at in 1980s and discarded for obvious reasons.
Calling Rob Painting: It seems to me that ENSO only affects top 300m of water column. Is this correct?
Moderator Response:[Rob P] - See Roemmich and Gilson (2011) - The Global Ocean Imprint of ENSO
Time-series of globally-averaged (60°S to 60°N) temperature anomaly from the monthly mean, versus pressure (dbar). The contour interval is 0.02°C and values are smoothed by 3-month running mean. (b) Time-series of globally-averaged SST (black, °C), T160 (blue), and the N34 regression estimate for SST (red).
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sidd at 14:47 PM on 15 April 2015The history of emissions and the Great Acceleration
To keep Ruddiman's view in perspective:
"The best-justified alignment of stages 11 and 1 indicates that the current interglaciation should have ended ~2000 years ago (or could end in the near future)."
from DOI: 10.1177/0959683610387172
and
" ... net early anthropogenic warming contribution of between 0.7°C and 1.2°C. This proposed early anthropogenic warming is comparable with, and likely larger than, the measured 0.85°C warming during the last 150 years. If the simulations based on the early anthropogenic hypothesis are correct, total anthropogenic warming has been twice or more the industrial amount registered to date."
and
"As summarized in Figure 3 (inset histograms) the net early anthropogenic warming of 1.2K is slightly larger than the instrumentally observed 0.85K warming of the industrial era to date. The total anthropogenic warming to date of ~2K is more than double the observed instrumental warming during the industrial era."
"These two phases of warming occurred within different contexts. The industrial-era warming has rapidly driven global temperature to a level that is poised to escape the top of its natural range over the last several hundred thousand years. In contrast, the early anthropogenic warming acted to offset part of a natural cooling but kept climate within the high end of its natural range. This natural cooling, most clearly evident at high northern latitudes, is generally ascribed to reduced summer insolation. The net effect of the natural Holocene cooling and the partially offsetting early anthropogenic warming was a small global cooling (Marcott et al., 2013)."
from
DOI: 10.1177/2053019614529263
So but for us, we would be in the beginning of a glaciation, but now we further force the climate into regimes unseen in at least a few hundred millennia well into the warm greenhouse of Kidder and Worsley described in
DOI: 10.1130/G131A.1
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PhilippeChantreau at 14:35 PM on 15 April 2015Global warming hiatus explained and it's not good news
volcano.oregonstate.edu/el-nino
www.ucar.edu/communications/gcip/m12anchovy/m12pdf.pdf
Pete Carson, I find your statement "I am a scientist" and your hypothesis "there is something in the water" do not quite square. Some evidence and peer-reviewed work is needed to support support such statements but you don't cite any in your comment.
A first step would be to lok at what actual scientific work has been done on the issue. With a very brief research, I found the article linked above. It specifies that several species of guano birds have a diet constituted of as much as 80% anchovy, and the anchovy populations off Peru have decreased in some El-Nino years, although they are not as affected as other sea life. Data do not show anchovy mortality to be caused by El-Ninos in any clear relation, except for the very large 1972 event. So far the evidence indicates that the hydrogen sulfide is procuded by decomposing organisms that are starved during El-Nino events, during which the normal cold water upwelling is stifled and the enire ecosystem suffers massive losses.
I had a hard time finding credible sources that had bothered to look at this but so far, it also appears that there is no correlation between any volcanic/seismic activity and El Nino events.
Per what I could find, your theory does not appear credible. What is your evidence?
Moderator Response:[RH] Shortened link.
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scaddenp at 14:19 PM on 15 April 2015Global warming hiatus explained and it's not good news
Your definition of "definitely" is wishful thinking. Firstly you would need to show H2S of volcanic origin. In fact, their biological origin is well studied as is effect of El nino. (eg see here but numerous other literature. Also this). The die-off isnt temperature per se but hypoxia and nutrient loss. There isnt a trail of death because warmer waters are already relatively barren compared to the nutrient-rich humbolt currrent - and yes, it hits the food chain all the way up to humans.
"This can only occur, in this area remote from human influence, from undersea volcanic activity" This is simply not true. See above reference but also very detailed study here. The H2S is of organic origin and associated with the changing sea conditions.
Now obviously noticing things like El Nino and volcanically active margin coincide is the source of scientific hypothesis but if you are going to make them work then you have derive predictions from your hypothesis and test them against observation. Now your theory appears to make a number of predictions:
1/ El Nino should be correlated with change in undersea volcanic productivity. None that I can see.
2/ H2S should be of volcanic composition and highly correlated with sources of volcanic eruption. Nope, it's organic and away from eruptive centers.
3/ The volcanoes need to be heating the water around them and so ARGO would show correlation between volcanoes and upwelling warm water. Nope. Actually its is worse, because the heat distribution at depth (very cold water) make no thermodynamic sense.
4/ The OHC content should match the heat from undersea volcanoes - not by a very long shot. This is a fatal blow frankly. It's orders of magnitude out.
You cant make an hypothesis stick if the maths doesnt work. There is no limit to the amount of nonsense hypotheses you can ignore the maths.
Compare this with the competing model for warming (increase in GHG) with agrees very well with the observations. Likewise the standard model of el nino. ENSO is an emergent property in coupled ocean-atmosphere models. Basin size, THC configuration and wind regime would appear to be why it is in Pacific. The models also account for vertical profile observed in TOA and ARGO.
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bozzza at 14:15 PM on 15 April 2015Global warming hiatus explained and it's not good news
Please don't tell us you're a scientist!
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Peter Carson at 13:55 PM on 15 April 2015Global warming hiatus explained and it's not good news
@29. bozzza
Why don't you just admit there is no difference?
(Wasn't it Einstein who said all things are relative?)
Oh! And I am a scientist. What are you doing here?
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bozzza at 13:38 PM on 15 April 2015Global warming hiatus explained and it's not good news
Peter Carson @ 27, if you don't want to accept the truth then what are you doing on a science forum?
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Peter Carson at 13:29 PM on 15 April 2015Global warming hiatus explained and it's not good news
@26 scanddenp.
As I sa
El Nino is definitely volcanic.
Evidence:
1. The sudden mass deaths of fish in the area at that time. Whatever is happening is caused locally.
The current EN theory says this is due to (maximum ca 5C) warmer water flowing into area from the west – then why there isn’t a trail of dead fish!? The EN area is usually cooler due to the Humboldt Current from Antarctica; it’s a stretch to say that temporary extra warmth would kill them.
There’s something in the water.
2. Seabirds are also killed. The warmer ocean obviously won’t adversely affect them, and with an abundance of fish waiting to be eaten, starvation won’t do it either.
There’s something in the water.
3. TheCallaoPainter. Fishing boats in the area during EN get “painted”. This is diagnostic for hydrogen sulphide, which “colour” the heavy-metal based paints.
The “something in the water” is therefore hydrogen sulphide (similar toxicity and action to cyanide). This can only occur, in this area remote from human influence, from undersea volcanic activity. Additionally, if one calculates how much sulphide is required to kill oceangoing fish, and assuming it constitutes ca 0.2% of lava mass, one gets about 10 to 20 cu. km (VEI of 6) in agreement with that calculated from the rate of divergence – as I suggested you do previously.
4. El Nino just happens to occur over perhaps the most volcanically active area on Earth.
El Nino is no orphan, tho’, and similar processes MUST occur at all divergent (particularly) boundaries. As I pointed out in my site’s “Cyclone Pam”, major cyclones initiate on tectonic boundaries. The divergent tectonic boundaries give a physical explanation to the various “Dipoles” which people have invented, that otherwise have none - other than statistical association.
[Yes, I know it’s not written very prettily, but I wanted it to get it out there while it’s fresh in people’s minds. I’ll clean it up…… eventually.]
id, I gave one example.
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Peter Carson at 13:21 PM on 15 April 2015Global warming hiatus explained and it's not good news
@25 bozzza
The difference being .....?
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scaddenp at 13:20 PM on 15 April 2015Global warming hiatus explained and it's not good news
Peter, if you want propose a theory, then you have ensure it is compatiable with all known observation data not just grabbing bits that suit you. El Nino is not volcanic, pure and simple. There is a massive literature with data on its actual causes. The H2S that is painting fish boats is from the biological source - the huge die-off that goes with the warmer temperatures. You can look this up for goodness sake. H2S from organic die-off has different isotopic signature from volcanic source H2S and there arent undersea volcanoes where H2S is bubbles are observed.
As for warmer water rising- are you aware of the ARGO network? Why is this then not observed? And why the massive discrepency between heat emitted from volcanoes and actual heat content? How do you account for the actual spatial distribution of OHC?
The extra heating from CO2 is actually observed. It is the correct magnitude to explain OHC and many many other things.
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bozzza at 13:00 PM on 15 April 2015Global warming hiatus explained and it's not good news
Warm water doesn't rise: cold water sinks!
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Peter Carson at 12:13 PM on 15 April 2015Global warming hiatus explained and it's not good news
@22 chriskoz. Looks like you’re on your own. Try answering yourself.
@ several: El Nino IS volcanic. Very quickly (but there is much more supporting data)
TheCallaoPainter. Fishing boats in the area during EN get “painted”. This is diagnostic for hydrogen sulphide, which “colour” the heavy-metal based paints.
@18 Tom Curtis. “..nor why the thermal gradient cools with depth rather than warms with depth as would be required if the major source of surface ocean heat was from the ocean floor.”
Could it be that warmer water rises?
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chriskoz at 11:26 AM on 15 April 2015Hungarian translation of The Debunking Handbook
It looks as "Hungarian skeptical movement" is the organisation like SkS team and most commenters who care about the accuracy of science and scientific communication.
On the other hand, in US for example, a similarly named "American skeptical movement" would likely be an organisation of deniers/science obfuscators.
Does it mean the meaning of the word "skeptic" has not been denigrated in Hungary and the hungarian "skeptics" (in american sense) are called properly "deniers"?
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DSL at 08:58 AM on 15 April 20152015 SkS Weekly Digest #15
Correction - forgot to update the rest of the dataset (can someone delete my last two posts?):
Still the 5th warmest month. Still the 3rd warmest March.
The 12-month period rankings for the last six months: 7, 18, 6, 4, 2, 1 (March).The 36-month period rankings for the last six months: 14, 22, 15, 3, 2, 1 (March).
Moderator Response:[PS] Deleted previous post as requested. The one previous is needed to make sense of it.
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Tom Curtis at 08:38 AM on 15 April 2015Andy Lacis responds to Steve Koonin
ranyl @15, although we have a stated likely range of 9 to 31 meters sea level rise at 392 ppmv, the lower bound does not start increasing again until about 550 ppmv, and the upper bound, though it increases, then decreases to about 29 meters from about 550-800 ppmv. On the postulate that increasing temperatures will not result in decreasing sea levels, that rise in the upper bound must be treated as simply a loss of certainty due to limited data over that interval and we have a prediction of essentially no further increase in sea level other than by thermal expansion from 390-800 ppmv.
To reach that state of relative stability, the WAIS and GIS must be essentially completely melted. That in turn indicates a sea level rise of about 14 meters from WAIS and GIS plus a little more from glacial ice and thermal expansion. So, assuming we will only have 9 meters of sea level rise is indeed folly based on that data. Sustained CO2 concentrations at current levels will give us 14 plus meters of sea level rise, but the same is true at 550 ppmv, and not till you get above 1000 ppmv is their any credible risk of the complete melt of the polar ice caps (the original point queried).
So far I have broadly agreed with you, though perhaps disagreed on detail. Where I truly disagree with you is on rates. While it is reasonable that a greater TOA energy imbalance (not forcing) will result in a faster ice melt, there are a host of other factors involved. One of those is surface area subject to ice melt which is far less with the surviving ice sheets than was the case at the end of the last glacial. Another is regional energy imbalance in the melt season, which was far greater at high northern latitudes (due to milankovitch "forcing") during the end of the last glacial than during the current anthropogenic temperature increase.
Further, even if I agreed with you about the possibility of 5 meters per century sea level rise in the current warming (which I do not), it would not be possible in this century. The current rate of sea level rise is about 0.32 meters per century. Even if that were to linearly increase to 5 meters per century by 2100, that would still only give us a sea level rise over the century of slightly less than 2.5 meters. (Less than because 14% of the century has already occured at low rates.) An exponential increase to that rate gives us a lower rise, not a greater rise - although it would predict a greater sea level rise in from 2100-2200. That, however, is itself a problem. Hansen's predictions suggest that most of the WAIS and GIS will melt out in less than fifty years early next century, a prediction which is not credible.
There is a reason why virtually nobody (I know of no actual cases) who is an expert is ice sheet dynamics or sea level rise accepts Hansen's predictions. There is a reason also why those who think the IPCC is too conservative expect sea level rises of the order of 2 meters or less for this century, not 5 meters.
If you want a more realistic assessment for this century, you should turn to Jevrejeva et al (2014):
"We construct the probability density function of global sea level at 2100, estimating that sea level rises larger than 180 cm are less than 5% probable. An upper limit for global sea level rise of 190 cm is assembled by summing the highest estimates of individual sea level rise components simulated by process based models with the RCP8.5 scenario. The agreement between the methods may suggest more confidence than is warranted since large uncertainties remain due to the lack of scenario-dependent projections from ice sheet dynamical models, particularly for mass loss from marine-based fast flowing outlet glaciers in Antarctica. This leads to an intrinsically hard to quantify fat tail in the probability distribution for global mean sea level rise. Thus our low probability upper limit of sea level projections cannot be considered definitive. Nevertheless, our upper limit of 180 cm for sea level rise by 2100 is based on both expert opinion and process studies and hence indicates that other lines of evidence are needed to justify a larger sea level rise this century."
(My emphasis)
Aslak Grinsted (one of the authors) writes on his blog:
"Any value for the upper-limit would meet opposition. Some would see it as overly alarmist, and others would argue that things could go a lot worse. We believe that with the methods we use, we fairly represent the broader community uncertainty.
For the ice sheet contribution we used a shap-shot of the expert uncertainty from 2012 (Bamber & Aspinall, 2013). Since then several studies have found that parts of Antarctica is already collapsing. This new knowledge may alter expert opinion (as we note in the paper), but we can only speculate by how much. This has led Joe Romm at Think Progress to argue that our study therefore "vastly* underestimates" worst case sea level rise. However, domain experts are ahead of the game, and ice sheet experts have long considered the possibility of a collapse. It is important to realize that the expert elicitation we used did not only ask for a best estimate, but asked each scientist to give a confidence interval. And it is clear from their responses that they did consider this possibility.
"This indicates a growing view that a significant marine ice-sheet instability in the WAIS could initiate in the coming century." -From Bamber & Aspinall 2013.
The new studies do not really inform on how fast that might happen, and I believe that the high-end would not change much if the same experts were asked the same question now. I speculate that these new studies will have a greater effect on what experts consider to be the most likely value, than the tail."
Further on the expert elicitation by Bamber and Aspinal, their 95% bound on elicited ice sheet contribution to sea level rise in 2100 was 17.61 mm per annum. Note that that is the sea level rise in that year. It means the expected average contribution over the century is approximately half that (or about 0.9 meters total contribution). The median is 5.4 mm per annum and mean of 6.9 mm per annum. The maximum elicited expert contribution was 38 mm per year (for an approximate expected contribution over the century of 1.9 meters). Hansen's views are so far outside the bounds of actual expert opinion on this topic as to be absurd.
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michael sweet at 07:15 AM on 15 April 20152015 SkS Weekly Digest #15
DSL,
What was the period ending in December? How far back do you need to go to get out of the current record streak?
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DSL at 06:51 AM on 15 April 20152015 SkS Weekly Digest #15
March GIS L-OTI is out: 0.84C. That's the 5th warmest month and the 3rd warmest March. The 12-month period ending in March is the warmest in the record, beating the periods ending in February (now 2) and January (now 3). Feb-Mar Multivariate ENSO Index was .65.
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PluviAL at 04:11 AM on 15 April 2015The history of emissions and the Great Acceleration
sailshrao, excellent observation, andyskuce's graphes are really illuminating to the idea that IF we could get fresh water to convert the deserts to agriculture we could absorb massive amounts of CO2 from the atmosphere, while releasing more delicate lands, rich in biodiversity, return to nature. Change in one direction release massive amoutns of CO2, in the other it absorbes similar amounts. The deserts are a very big potential CO2 spunge.
I'm thinking of something like massive and sustainable "San Joaquin" valleys through the desert belts of the world. The only challenge is fresh water, but if you think about it, that is also the problem, there is too much water in the atmosphere as the planet heats up. Water is also a great way to convert excess heat into humidity again leading to fresh water. From my studies this is the solution. This is what I meant to say by "continuing the great acceleration" of wealth creation, while creating a "Great Absorption" of atmospheric CO2.
There are two way to get that water: 1) From the atmosphere, this produces energy while producing fresh water. 2) Diversion from the arctic rivers. While this is a potentially catastrophic on environmental disruption, it is less so than loss of Gulf Steam circulation (GSC), which such action would help to curve. There is one more action to retain it GSC but that's another story.
I know this sounds crazy, but people here know better than anyone that what we are experimenting with through geologic scale fossil fules oxidation, is much crazier.
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ranyl at 22:11 PM on 14 April 2015Andy Lacis responds to Steve Koonin
"Earth system were to reach equilibrium with modern or future
CO2 forcing. Given the present-day (AD 2011) atmospheric CO2
concentration of 392 ppm, we estimate that the long-term sea level
will reach +24 +7/−15 m (at 68% confidence) relative to the present."That was at 392ppm.
http://www.pnas.org/content/110/4/1209.full.pdf
As the early Pliocene was ~350-400ppm, with most of the later papers with more accurate calculations are pointing more to 350ppm, and sea levels were 20-25m higher.
This is were stats lets us down really, for everyone will grasp at the seeming chance of 16% that sea level rise will be below 9m, for this is resultant from taking a wide range of sea levels and CO2 levels uncertainities and arriving this larger uncertainity, yet no expert in the paleoclimatology would agree that the Pliocene wasn't warmer and that sea levels weren't 20m higher, when CO2 was ~350-400ppm.
Also interesting that 5cm a year rates of sea levels rise have occured in deglaciations when the general global warming was occuring an order or two magnitude slower than current rates.
Seems reasonable to suggest that the fasterthe ehat accumulates in the system the faster the ice sheets will melt, and it is well known that melting an ice sheet is an ever accelerating event due to icesheet lowering and dynamic melting processes (e.g.the heat from surface melt ponds being transfered to the heart of the ice sheet).
That is why Hansen wonders at 5m in a century and why most feel the IPCC 0.8m by 2100 is generally regarded as very conservative.
Moderator Response:[PS] Fixed link. It would be appreciated if you did this yourself with the Link button in the comment editor.
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Tristan at 20:32 PM on 14 April 20152015 SkS Weekly Digest #15
Thank you very much Tom, I appreciate you spelling it out to me.
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billthefrog at 20:24 PM on 14 April 2015Andy Lacis responds to Steve Koonin
As Tom has pointed out, when one is considering eustatic sea level rise (i.e. the rise due to more water being added to the oceans) the behaviour of the East Antarctic Ice Sheet will not simply mimic that of the Greenland Ice Sheet, the West Antarctic Ice Sheet or the Antarctic Peninsula.
The EAIS is at a much higher elevation than its smaller counterparts, and would need considerably more (and longer) planetary warming before it would even come close to melting out. Those wishing to learn a bit more might care to look at the Antarctic Glaciers website, or at the British Antarctic Survey site.
There is little meaningful argument that the Mass Balance for each of the GIS, the WAIS and the Peninsula is in negative territory. However, the EAIS may actually be accumulating ice at present, as enhanced precipitation in its central regions (thanks to the good old Clausius-Claperyon relationship) could be more than compensating for increased peripheral loss.
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Tristan at 19:58 PM on 14 April 2015CO2 limits will harm the economy
Maybe this has been talked about in the comments: Where might I find a detailed examination of the likely performance of an ETS vs Carbon Tax/Fee and Dividend?
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Tom Curtis at 18:43 PM on 14 April 20152015 SkS Weekly Digest #15
Tristan @1, similar claims have been made on SkS before, and discussed in detail. The validity of the claim depends, however, on the way it is formulated. In this case, based on IPCC AR5 figures, to counterbalance total annual anthropogenic emissions, humans need only increase total terrestial photosynthesis (ie, Gross Primary Productivity) by 8.9 GtC, or 7.24%. That is, of course, the figures for all terrestial photosynthesis, not just crop land. Taking the figures of Haberl et al (2007), that equates to increasing agricultural productivity by 57.1% of current human appropriation of net primary productivity or 107.6% of the current harvestable yield.
I don't know whether that is technically feasible, but it does not present a theoretical bar. However, that increase must be the increase in persistent biomass. Any actual crop, whether consumed by humans or as fodder for animals, returns to the atmosphere as CO2, and hence is not sequestered. The sequestration, therefore, is limited to the annual increase in standing biomass and soil biomass. Here, however, you face a problem. Based on the IPCC AR5, human activity has reduced terrestial biomass by just 30 GtC since the industrial revolution. That is, if we could manage that rate of sequestration, we would have to exceed natural levels of sequestration within 3.4 years. That figure is less the increase in biomass due to increased temperature, water, CO2 and the agricultural revolution. On an alternative measure, we would be exceeding natural levels 18.4 years (remember to convert from GtCO2 to GtC if checking the figures). Allowing for preindustrial levels, we might have 36 to 40 years of such sequestration before we reached a situation where the land simply would not hold more biomass. So, while such high rates of sequestration cannot be excluded, neither can they be maintained sufficiently to provide a long term solution.
Finally, many of the changes suggested require convesion to small scale, labour intensive farming (permaculture). The problem with that is it requires the majority of the population to be farmers. It represents a retreat back to a dark age, where we do not have sufficient resources to maintain a system of universities and scholarship, or of mass entertainment (which may be of interest to more people).
I am not suggesting that implication of the methods advocated by Savory or the Rodale institute are not worthwhile in themselves, or that they will not help. They are just not a silver bullet for global warming, and they make themselve incredible (ie, not capable of being believed) by suggesting otherwise.
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Tristan at 15:29 PM on 14 April 20152015 SkS Weekly Digest #15
I'm not quite sure where to put this, it may not be within the remit of this site. I'm just wondering if this might be an example of 'misinformation' from team environment.
"According to the Rodale Institute, small-scale farmers and pastoralists could sequester more than 100% of current annual CO2 emissions with a switch to widely available, safe and inexpensive agroecological management practices that emphasize diversity, traditional knowledge, agroforestry, landscape complexity, and water and soil management techniques, including cover cropping, composting and water harvesting."
http://www.commondreams.org/views/2015/04/13/food-farming-and-climate-change-its-bigger-everything-else
WIthout a background in ag science, I can't evaluate the truthiness of that.
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John Brookes at 15:07 PM on 14 April 2015Andy Lacis responds to Steve Koonin
Thanks for a very clear explanation.
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Tom Curtis at 14:24 PM on 14 April 2015Andy Lacis responds to Steve Koonin
mrkt @10, looking carefully at the graph in the upper right panel, it becomes clear that they show a "likely range" (68%) at 9 to 59 meters at 450 ppmv. That makes their claim of a "likely (68% confidence) long-term sea-level rise by more than 9 m above the present" true, but obscure. Ie, they are saying that the likely confidence interval, using IPCC methods of expressing confidence, has a lower limit of 9 m. From that it follows that their results show an 84% probability of at least 9 meters of sea level rise for a long term CO2 concentration of 450 ppmv.
That is not how I initially read it, so thank you for drawing attention to my error.
Looking at their likely range, over that interval, it appears evident that the upper value is so large due entirely to the limitted observations. On the assumption that increased temperatures will not cause water to refreeze, I think the lowest upper limit of the likely range at higher temperatures can also be used as a more realistic upper limit for a long term 450 ppmv concentration. That produces an adjusted likely range between 9 and 30 meters, with 30 meters representing the almost complete melt of the WAIS and GIS, with any surviving ice from those ice sheets being more than compensated for by melt of the EAIS.
bozza @11, the flat line is because while the WAIS and GIS are on the verge of melting, the EAIS is much more stable , and will mostly remain intact once the WAID and GIS have melted away with little melting other than at the fringes. Only after considerable further rise in temperature will the EAIS melt away.
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bozzza at 12:23 PM on 14 April 2015Andy Lacis responds to Steve Koonin
@ 9, I think this is surely the relevant question at the moment!
@ 7, why things flatline and/or double dip I don't know but the links should prove interesting- cheers.
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mrkt at 09:46 AM on 14 April 2015Andy Lacis responds to Steve Koonin
Tom Curtis @7: In looking closely at the graphs, it appears that a 9 meter rise corresponds to 1 std. dev. below the mean. This would imply that the chance of less than 9 meters is 16%, and the chance of more than 9 meters is 84% rather than 68%. No? Clearly not a better situation. (I do note that you are quoting the paper.)
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scaddenp at 09:38 AM on 14 April 2015Andy Lacis responds to Steve Koonin
I think it would be accurate however to say the 450ppm is incompatible with the ice-age cycle. (Didnt have ice ages when atmosphere was last at 450ppm, though there were still polar ice caps.)
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Tom Curtis at 09:02 AM on 14 April 2015Andy Lacis responds to Steve Koonin
gregcharles @5, the CO2 in the atmosphere does not reflect IR radiation back towards the Earth. Rather, it absorbs it, and then reradiates it. The difference is important, because if reflected the energy returned would be the difference between that which the surface emits (398 W/m^2) and that which escapes the atmosphere (239 W/m^2), ie 159 W/m^2. In fact, downwelling IR radiation (or back radiation) averages around 342 W/m^2 because the IR radiation from the atmosphere (figures from IPCC AR5):
The much higher back radiation is due to the air mass immediately above the Earth's surface (from which most of the back radiation originates) having a temperature very close to that at the surface. In constrast, most of the IR radiation to space comes from high in the troposphere, where the temperatures are much lower.
Further, the actual back radiation is not important to the greenhouse effect (although may be important for local weather events). That is because if the back radiation were to increase, with no change in the greenhouse effect, evaporation and sensible heat transfers would also increase to maintain a balance, and if it were to decrease, evaporation and sensible heat would also decrease. The greenhouse effect is determined by the top of atmosphere energy balance.
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Tom Curtis at 08:44 AM on 14 April 2015Andy Lacis responds to Steve Koonin
CBDunkerson @1, Bozza @2, the most recent credible data that I know of is encapsulated in this figure:
(Source)
Total melting of the ice caps is associated with a sea level rise greater than 70 meters. Ergo, from paleo data, we cannot expect that unless we have sustained CO2 concentrations of 800-1500 ppmv. From that paper (Foster and Rohling 2013), we lean that "our results imply that acceptance of a longterm 2 °C warming [CO2 between 400 and 450 ppm (46)] would mean acceptance of likely (68% confidence) long-term sea-level rise by more than 9 m above the present." That probably represents the melting of the West Antarctic Ice Sheet (WAIS), and the partial melting of the Greenland Ice Sheet (GIS), with only limited melting of the East Antarctic Ice Sheet (EAIS).
Looking at the figure, Andy Lacis may be basing his claim on van der Wal et al, 2011, except that when I actually look at van der Wal et al, the modelling shows a total loss of polar ice does not occur until a sustained temperature anomaly of plus 20 C is reached, ie, around 1600 ppmv with an Earth System Climate Sensitivity of 8 C. It appears, therefore, that Foster and Rohling have incorrectly represented van der Wal et al's results.
Aslak Grinstead gives a more detailed discussion.
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Andy Lacis responds to Steve Koonin
gregcharles - The Earth isn't in equilibrium right now, increasing ocean heat content (OHC) measures show that over the last 50 years we've averaged about a 0.6 W/m2 mbalance over that period, meaning the earth has been receiving about 240 W/m2 and radiating about 239.4 W/m2. The difference points to the (currently) unrealized warming due to thermal lag, primarily in the oceans.
The difference between the near-blackbody IR radiation at the Earths surface (~396 W/m2, IR emissivity about 0.95-0.98) and what's radiated to space (~240 W/m2) is entirely due to the radiative greenhouse effect - in essence energy isn't emitted to space until much higher altitudes (and colder) due to greenhouse gases, making the effective emissivity of the Earth in IR around 0.61. The Earth's just not as effective a radiator as a bare rock would be, and with increasing GHGs it becomes even less effective - hence a higher and higher surface temperature required to radiate the same energy to space.
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gregcharles at 07:27 AM on 14 April 2015Andy Lacis responds to Steve Koonin
I agree that 450ppm by the end of the century is an understatement. Everything I've seen suggests we'll reach that mark within the next 20 years.
I have a couple of questions about the Fourier calculations. First, the global mean temperature of 288K implying 390 W/m2 of radition, some into space and some reflected back to earth by greenhouse gasses. I'd like to know more about how that's calculated.
I also don't fully understand the near-global energy balance used as the reason earth absorbs 240 W/m2 of radiation from the sun and radiates the same amount out of the upper atmosphere. The earth isn't in equilibrium now is it? We'd still warm for quite awhile even if CO2 levels remained constant, right? Doesn't that imply we're absorbing more radiation from the sun than we're radiating back into space? I feel like I'm missing something obvious here.
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