From CO2Science:
Medieval Warm Period (Antarctica) — Summary
Was there a Medieval Warm Period somewhere in the world in addition to the area surrounding the North Atlantic Ocean, where its occurrence is uncontested? This question is of utmost importance to the ongoing global warming debate, for if the Medieval Warm Period is found to have been a global climatic phenomenon, and if the locations where it occurred were as warm in medieval times as they are currently, there is no need to consider the temperature increase of the past century as anything other than the natural progression of the persistent millennial-scale oscillation of climate that regularly brings the earth several-hundred-year periods of modestly higher and lower temperatures that are totally independent of variations in atmospheric CO2 concentration. Consequently, we here review the findings of several studies that have found evidence for the Medieval Warm Period in a region that is as far away from lands bordering on the North Atlantic Ocean as one could possibly get, i.e., Antarctica.
Hemer and Harris (2003) extracted a sediment core from beneath the Amery Ice Shelf, East Antarctica, at a point that is currently about 80 km landward of the location of its present edge. In analyzing the core’s characteristics over the past 5,700 14C years, the two scientists observed a peak in absolute diatom abundance in general, and the abundance of Fragilariopsis curta in particular-which parameters, in their words, “are associated with increased proximity to an area of primary production, such as the sea-ice zone”-at about 750 14C yr B.P., which puts the time of maximum Ice Shelf retreat in close proximity to the historical time frame of the Medieval Warm Period.
Khim et al. (2002) likewise analyzed a sediment core removed from the eastern Bransfield Basin just off the northern tip of the Antarctic Peninsula, including grain size, total organic carbon content, magnetic susceptibility, biogenic silica content, 210Pb geochronology, and radiocarbon (14C) age, all of which data clearly depicted, in their words, the presence of the “Little Ice Age and Medieval Warm period, together with preceding climatic events of similar intensity and duration.”
Working in the same general region of the continent, Hall et al. (2010) write that “over the past 50 years, the Antarctic Peninsula warmed ~2°C,” and that resultant rapid ice breakups “have destroyed several small, thin ice shelves fringing the Antarctic Peninsula (i.e., Cook and Vaughan, 2009, and references therein),” leading them to ask, “is the recent warming of the Antarctic Peninsula unique in the Holocene?”
In an effort to place the current ice recession in a broader context, the three researchers “examined organic-rich sediments exposed by the recent retreat of the Marr Ice Piedmont on western Anvers Island near Norsel Point,” where glaciers “have been undergoing considerable retreat in response to the well-documented warming.” There, they “obtained moss and reworked marine shells from natural sections within 26 meters of the present ice front,” as well as “both peat and reworked shells from sediments exposed in a tunnel beneath the residual ice mass,” samples of which were radiocarbon-dated and the results converted to calendar years.
The results they obtained by these means indicated peat from the overrun sediments dated to between 707 ± 36 and 967 ± 47 cal. yr B.P.,” which led them to conclude, “ice was at or behind its present position at ca. 700-970 cal. yr B.P. and during at least two earlier times, represented by the dates of shells, in the mid-to-late Holocene.” Then, in language pure and simple, the three researchers say their findings imply that “the present state of reduced ice on the western Antarctic Peninsula is not unprecedented.” This leads them to pose another important question: “How widespread is the event at 700-970 cal. yr B.P.?”
In answering their own query, the researchers respond that (1) “Khim et al. (2002) noted a pronounced high-productivity (warm) event between 500 and 1000 cal. yr B.P. in magnetic susceptibility records from Bransfield Basin,” (2) “dates of moss adjacent to the present ice front in the South Shetland Islands (Hall, 2007) indicate that ice there was no more extensive between ca. 650 and 825 cal. yr B.P. than it is now,” (3) “evidence for reduced ice extent at 700-970 cal. yr B.P. is consistent with tree-ring data from New Zealand that show a pronounced peak in summer temperatures (Cook et al., 2002),” (4) “New Zealand glaciers were retracted at the same time (Schaefer et al., 2009),” and (5) their most recent findings “are compatible with a record of glacier fluctuations from southern South America, the continental landmass closest to Antarctica (Strelin et al., 2008).” In light of these several observations, therefore, it would appear that much of the southernmost portion of the Earth likely experienced a period of significantly enhanced warmth within the broad timeframe of the planet’s global MWP. And this interval of warmth occurred when there was far less CO2 and methane in the atmosphere than there is today.
In one additional study from the Antarctic Peninsula, Lu et al. (2012) constructed “the first downcore δ18O record of natural ikaite hydration waters and crystals collected from the Antarctic Peninsula (AP)” that they say were “suitable for reconstructing a low resolution ikaite record of the last 2000 years.” According to the group of nine UK and US researchers, ikaite “is a low temperature polymorph of calcium carbonate that is hydrated with water molecules contained in its crystal lattice,” and they write that “ikaite crystals from marine sediments, if collected and maintained at low temperatures, preserve hydration waters and their intact crystal structures, both of which have the potential to provide isotopic constraints on past climate change.” So what did they find?
The authors report that “the ikaite record qualitatively supports that both the Medieval Warm Period and Little Ice Age extended to the Antarctic Peninsula.” They also state that the “most recent crystals suggest a warming relative to the LIA in the last century, possibly as part of the regional recent rapid warming,” but they add that “this climatic signature is not yet as extreme in nature as the MWP,” suggesting that even the dramatic recent warming of the AP may not yet have returned that region to the degree of warmth that was experienced there during the MWP, when the atmosphere’s CO2 concentration was more than 100 ppm less than it is today.
Examining a different region of the continent, Hall and Denton (2002) mapped the distribution and elevation of surficial deposits along the southern Scott Coast of Antarctica in the vicinity of the Wilson Piedmont Glacier, which runs parallel to the coast of the western Ross Sea from McMurdo Sound north to Granite Harbor. The chronology of the raised beaches they studied was determined from more than 60 14C dates of incorporated organic materials they had previously collected from hand-dug excavations (Hall and Denton, 1999); the record the dates helped define demonstrated that near the end of the Medieval Warm Period, “as late as 890 14C yr BP,” as Hall and Denton describe it, “the Wilson Piedmont Glacier was still less extensive than it is now,” demonstrating that the climate of that period was in all likelihood considerably warmer than it is currently.
Several years later, but also working in the Ross Sea region of Antarctica, Bertler et al. (2011) obtained new deuterium (δD) data acquired via analysis of the top fifty meters of a 180-meter-long ice core that had been extracted from the ice divide of Victoria Lower Glacier in the northernmost McMurdo Dry Valleys, which they converted to temperature data by means of a temperature-isotope relationship developed by Steig et al. (1998) from data obtained from the Taylor Dome ice core record. In doing so, Bertler et al. report that they identified three distinct time periods in their record: the last 150 years of the Medieval Warm Period (AD 1140 to 1287), the Little Ice Age (AD 1288 to 1807), and the Modern Era (AD 1808 to 2000). And with respect to the Medieval Warm Period, they write that “the McMurdo Dry Valleys were 0.35°C warmer during the MWP than during ME, accompanied by warmer conditions in the Ross Sea.” The three researchers also note that “a magnetic susceptibility record from Palmer Deep marine core (PD92 30MS) also supports warmer MWP conditions, this time in Drake Passage (Domack and Mayewski, 1999).”
Noon et al. (2003) used oxygen isotopes preserved in authigenic carbonate retrieved from freshwater sediments of Sombre Lake on Signy Island (60°43’S, 45°38’W) in the Southern Ocean to construct a 7,000-year history of that region’s climate. This work revealed that the general trend of temperature at the study site has been downward. Of most interest to the present discussion, however, is the millennial-scale oscillation of climate that is apparent in much of the record. This climate cycle is such that approximately 2,000 years ago, after a thousand-year gap in the data, Signy Island experienced the relative warmth of the last vestiges of the Roman Warm Period, as delineated by McDermott et al. (2001) on the basis of a high-resolution speleothem δ18O record from southwest Ireland. Then comes the Dark Ages Cold period, which is also contemporaneous with what McDermott et al. observe in the Northern Hemisphere, after which the Medieval Warm Period appears at the same point in time and persists for the same length of time that it does in the vicinity of Ireland, whereupon the Little Ice Age sets in just as it does in the Northern Hemisphere. Finally, there is an indication of late twentieth century warming, but with still a long way to go before conditions comparable to those of the Medieval Warm Period are achieved.
Two years later, Castellano et al. (2005) derived a detailed history of Holocene volcanism from the sulfate record of the first 360 meters of the Dome Concordia ice core that covered the period 0-11.5 kyr BP, after which they compared their results for the past millennium with similar results obtained from eight other Antarctic ice cores. Before doing so, however, they normalized the results at each site by dividing their several volcanic-induced sulfate deposition values by the value produced at that site by the AD 1816 Tambora eruption, in order to reduce deposition differences among sites that might have been induced by differences in local site characteristics. This work revealed that most volcanic events in the early last millennium (AD 1000-1500) exhibited greater among-site variability in normalized sulphate deposition than was observed thereafter.
Citing Budner and Cole-Dai (2003) in noting that “the Antarctic polar vortex is involved in the distribution of stratospheric volcanic aerosols over the continent,” Castellano et al. say that assuming the intensity and persistence of the polar vortex in both the troposphere and stratosphere “affect the penetration of air masses to inland Antarctica, isolating the continental area during cold periods and facilitating the advection of peripheral air masses during warm periods (Krinner and Genthon, 1998), we support the hypothesis that the pattern of volcanic deposition intensity and geographical variability [higher values at coastal sites] could reflect a warmer climate of Antarctica in the early last millennium,” and that “the re-establishment of colder conditions, starting in about AD 1500, reduced the variability of volcanic depositions.”
Describing this phenomenon in terms of what it implies, Castellano et al. say “this warm/cold step could be like a Medieval Climate Optimum-like to Little Ice Age-like transition.” They additionally cite Goosse et al. (2004) as reporting evidence from Antarctic ice-core δD and δ18O data “in support of a Medieval Warming-like period in the Southern Hemisphere, delayed by about 150 years with respect to Northern Hemisphere Medieval Warming.” And the researchers conclude by postulating that “changes in the extent and intra-Antarctic variability of volcanic depositional fluxes may have been consequences of the establishment of a Medieval Warming-like period that lasted until about AD 1500.”
A year later, Hall et al. (2006) collected skin and hair (and even some whole-body mummified remains) from Holocene raised-beach excavations at various locations along Antarctica’s Victoria Land Coast, which they identified by both visual inspection and DNA analysis as coming from southern elephant seals, and which they analyzed for age by radiocarbon dating. By these means they obtained data from 14 different locations within their study region-which they describe as being “well south” of the seals’ current “core sub-Antarctic breeding and molting grounds”-that indicate that the period of time they denominate the Seal Optimum began about 600 BC and ended about AD1400, the latter of which dates they describe as being “broadly contemporaneous with the onset of Little Ice Age climatic conditions in the Northern Hemisphere and with glacier advance near [Victoria Land’s] Terra Nova Bay.”
In describing the significance of their findings, the US, British, and Italian researchers say they are indicative of “warmer-than-present climate conditions” at the times and locations of the identified presence of the southern elephant seal, and that “if, as proposed in the literature, the [Ross] ice shelf survived this period, it would have been exposed to environments substantially warmer than present,” which would have included both the Roman Warm Period and Medieval Warm Period.
Advancing one year closer to the present, Williams et al. (2007) presented methyl chloride (CH3Cl) measurements of air extracted from a 300-m ice core that was obtained at the South Pole, Antarctica, covering the time period 160 BC to AD 1860. In describing what they found, the researchers say “CH3Cl levels were elevated from 900-1300 AD by about 50 ppt relative to the previous 1000 years, coincident with the warm Medieval Climate Anomaly (MCA),” and that they “decreased to a minimum during the Little Ice Age cooling (1650-1800 AD), before rising again to the modern atmospheric level of 550 ppt.” Noting that “today, more than 90% of the CH3Cl sources and the majority of CH3Cl sinks lie between 30°N and 30°S (Khalil and Rasmussen, 1999; Yoshida et al., 2004),” they say “it is likely that climate-controlled variability in CH3Cl reflects changes in tropical and subtropical conditions.” They go on to say that “ice core CH3Cl variability over the last two millennia suggests a positive relationship between atmospheric CH3Cl and global [italics added] mean temperature.”
As best as can be determined from the graphical representation of their data, the peak CH3Cl concentration measured by Williams et al. during the MCA is approximately 533 ppt, which is within 3 percent of its current mean value of 550 ppt and well within the range of 520 to 580 ppt that characterizes methyl chloride’s current variability. It may therefore be validly concluded that the mean peak temperature of the MCA (which is herein referred to as the Medieval Warm Period) over the latitude range 30°N to 30°S-and possibly over the entire globe-may not have been materially different from the mean peak temperature so far attained during the Current Warm Period.
In one final study, Hall (2007) presented “radiocarbon and geomorphologic data that constrain [the] late-Holocene extent of the Collins Ice Cap on Fildes Peninsula (King George Island, South Shetland Islands: 62°10’51″S, 58°54’13″W),” which, in her words, “yield information on times in the past when climate in the South Shetland Islands must have been as warm as or warmer than today,” based on field mapping of moraines and glacial deposits adjacent to the ice cap, as well as radiocarbon dates of associated organic materials. Such data, according to Hall, “indicate ice advance after ~650 cal. yr BP (AD ~1300),” which she notes is “broadly contemporaneous with the ‘Little Ice Age’, as defined in Europe.” She also says that this was “the only advance that extended beyond the present ice margin in the last 3500 years, making the Little Ice Age in that part of the world likely the coldest period of the current interglacial. And the fact that “the present ice cap margin … is still more extensive than it was prior to ~650 cal. yr BP” led her to conclude that the climate prior to that time — which would have comprised the Medieval Warm Period — may have been “as warm as or warmer than present.” And this conclusion, along with the findings of the other studies reviewed herein, suggests there is nothing that is unusual, unnatural or unprecedented about the current level of Earth’s warmth, which further suggests that the historical increase in the atmosphere’s CO2 concentration may not have had anything to do with concomitant 20th-century global warming.
References
Bertler, N.A.N., Mayewski, P.A. and Carter, L. 2011. Cold conditions in Antarctica during the Little Ice Age — Implications for abrupt climate change mechanisms. Earth and Planetary Science Letters 308: 41-51.
Budner, D. and Cole-Dai, J. 2003. The number and magnitude of large explosive volcanic eruptions between 904 and 1865 A.D.: Quantitative evidence from a new South Pole ice core. In: Robock, A. and Oppenheimer, C. (Eds.), Volcanism and the Earth’s Atmosphere, Geophysics Monograph Series 139: 165-176.
Castellano, E., Becagli, S., Hansson, M., Hutterli, M., Petit, J.R., Rampino, M.R., Severi, M., Steffensen, J.P., Traversi, R. and Udisti, R. 2005. Holocene volcanic history as recorded in the sulfate stratigraphy of the European Project for Ice Coring in Antarctica Dome C (EDC96) ice core. Journal of Geophysical Research 110: 10.1029/JD005259.
Cook, A.J. and Vaughan, D. 2009. Overview of areal changes of the ice shelves on the Antarctic Peninsula over the past 50 years. The Cryosphere Discussions 3: 579-630.
Cook, E., Palmer, J., and D’Arrigo, R. 2002. Evidence for a “Medieval Warm Period” in a 1100-year tree-ring reconstruction of past austral summer temperatures in New Zealand. Geophysical Research Letters 29: 10.1029/2001GL014580.
Domack, E.W. and Mayewski, P.A. 1999. Bi-polar ocean linkages: evidence from late-Holocene Antarctic marine and Greenland ice-core records. The Holocene 9: 247-251.
Goosse, H., Masson-Delmotte, V., Renssen, H., Delmotte, M., Fichefet, T., Morgan, V., van Ommen, T., Khim, B.K. and Stenni, B. 2004. A late medieval warm period in the Southern Ocean as a delayed response to external forcing. Geophysical Research Letters 31: 10.1029/2003GL019140.
Hall, B.L. 2007. Late-Holocene advance of the Collins Ice Cap, King George Island, South Shetland Islands. The Holocene 17: 1253-1258.
Hall, B.L. and Denton, G.H. 1999. New relative sea-level curves for the southern Scott Coast, Antarctica: evidence for Holocene deglaciation of the western Ross Sea. Journal of Quaternary Science 14: 641-650.
Hall, B.L. and Denton, G.H. 2002. Holocene history of the Wilson Piedmont Glacier along the southern Scott Coast, Antarctica. The Holocene 12: 619-627.
Hall, B.L., Hoelzel, A.R., Baroni, C., Denton, G.H., Le Boeuf, B.J., Overturf, B. and Topf, A.L. 2006. Holocene elephant seal distribution implies warmer-than-present climate in the Ross Sea. Proceedings of the National Academy of Sciences USA 103: 10,213-10,217.
Hall, B.L., Koffman, T., and Denton, G.H. 2010. Reduced ice extent on the western Antarctic Peninsula at 700-907 cal. yr B.P. Geology 38: 635-638.
Hemer, M.A. and Harris, P.T. 2003. Sediment core from beneath the Amery Ice Shelf, East Antarctica, suggests mid-Holocene ice-shelf retreat. Geology 31: 127-130.
Khalil, M.A.K. and Rasmussen, R.A. 1999. Atmospheric methyl chloride. Atmospheric Environment 33: 1305-1321.
Khim, B-K., Yoon, H.I., Kang, C.Y. and Bahk, J.J. 2002. Unstable climate oscillations during the Late Holocene in the Eastern Bransfield Basin, Antarctic Peninsula. Quaternary Research 58: 234-245.
Krinner, G. and Genthon, C. 1998. GCM simulations of the Last Glacial Maximum surface climate of Greenland and Antarctica. Climate Dynamics 14: 741-758.
Lu, Z., Rickaby, R.E.M., Kennedy, H., Kennedy, P., Pancost, R.D., Shaw, S., Lennie, A., Wellner, J. and Anderson, J.B. 2012. An ikaite record of late Holocene climate at the Antarctic Peninsula. Earth and Planetary Science Letters 325-326: 108-115.
McDermott, F., Mattey, D.P. and Hawkesworth, C. 2001. Centennial-scale Holocene climate variability revealed by a high-resolution speleothem δ18O record from SW Ireland. Science 294: 1328-1331.
Noon, P.E., Leng, M.J. and Jones, V.J. 2003. Oxygen-isotope (δ18O) evidence of Holocene hydrological changes at Signy Island, maritime Antarctica. The Holocene 13: 251-263.
Schaefer, J., Denton, G., Kaplan, M., Putnam, A., Finkel, R., Barrell, D.J.A., Andersen, B.G., Schwartz, R., Mackintosh, A., Chinn, T., and Schluchter, C. 2009. High-frequency Holocene glacier fluctuations in New Zealand differ from the northern signature. Science 324: 622-625.
Steig, E.J., Brook, E.J., White, J.W.C., Sucher, C.M., Bender, M.L., Lehman, S.J., Morse, D.L., Waddington, E.D. and Clow, G.D. 1998. Synchronous climate changes in Antarctica and the North Atlantic. Science 282: 92-95.
Strelin, J., Casassa, G., Rosqvist, G., and Holmlund, P. 2008. Holocene glaciations in the Ema Glacier valley, Monte Sarmiento Massif, Tierra del Fuego. Palaeogeography, Palaeoclimatology, Palaeoecology 260: 299-314.
Williams, M.B., Aydin, M., Tatum, C. and Saltzman, E.S. 2007. A 2000 year atmospheric history of methyl chloride from a South Pole ice core: Evidence for climate-controlled variability. Geophysical Research Letters 34: 10.1029/2006GL029142.
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Sorry richard if I read this all wrong but what does the following present? It is actually one of the references above. Here is the summary.
And
Abstract
……These warmer regional episodes were not strongly synchronous……..
Malcolm K. Hughes, – 1994
http://link.springer.com/article/10.1007/BF01092410
How strong is strong?
Steven Mosher
You make a silly assumption that the forcing between the MWP and LIA was only 0.5W/m2.
This is ridiculous
Between 1987 and 2000 there was a 5% decrease in cloud cover corresponding to a 0.9w/m2 forcing and the corresponding change in global temp was approximately 0.3-0.4 deg C including the extra forcing from greenhouse gases.
This compares to the 0.6deg expected just from greenhouse gasses in the last 30 years and the 2deg expected in the last 100 years if climate sensitivity was high.
The forcing between the MWP and LIA is more likely to be in the 10-15W/m2 range than 0.5 W/m2.
Some Warmists have said that the Medieval Warm Period was NOT globally synchronous. Fine. Now imagine if the following was to occur today. What would they say? There would be much gnashing and grinding of teeth about climate change. It would make the front page news as a sure sign of GLOBAL WARMING!!! They think they a dealing with a bunch of fools. By the way this was not the weather but the climate!!!
What was that about the Arctic melt and colder winters? How is one to make head or tail of this?
Brant Ra says:
April 11, 2013 at 9:22 am
@richard verney Sorry dude, you cannot cut granite with copper chisels…
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The Giza plateau is made of limestone, not granite.
The great Pyramid was constructed approximately 2,500BC.
The iron age has no uniform chronological date (it depends upon regions, warmer climes usually being in advance of cooler climes) but is generally around 1300BC in Egypt, Cyprus, Aegean, although there are a few ancient Egyptian iron artefacts that date earlier.
Steven Mosher says:
April 11, 2013 at 8:25 am
Bottomline: the bigger the swing between the MWP and the LIA, the HIGHER the sensitivity.
The bigger the swing in natural oscillations the higher our risk from anthro forcing.
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No, that only works (maybe) if climate is linear. Chaotic systems do not respond in that fashion. For example, Apollo 13 did not have enough fuel to return home, yet they made it. The forcing remained exactly the same, yet they were able to obtain a greater Delta by selecting a different, lower energy path. This is impossible using a simplistic linear model.
In the linear model there is only one path to the future. In a linear world the future is a clockwork result of the past. Everything is already written by the initial state of the universe. Quantum mechanics tells us otherwise. There are infinite paths to the future with each no more than a probability. No future result is certain, regardless of forcings or feedbacks.
It is apparent that Steve Mosher and the climate science community conside all forcings to be the same, IE, two watts per sq’M of solar increase, is the same as two watts per sq’M back radiation due to CO2. I find this quites astounding, even ignoring the herd of donkey assumtions with regard to the CO2 forcing.
Let us say that today those two forcings both happen at the same time, they will not have the same affect, as they travel different roads. Now tonight the CO2 is likely to, at best, delay the timeing of the evening low. The erth continues to radiatively cool through the night, by the time of sunrise most all that extra energy has left the atmosphere. However the solar input, that has fallen on about 2/3rds ocean, 1% of the insolation penetrating from 200 to 800 feet. none of that 1% energy has left the earth, and tomorrow and for the next dozen years, or more, if the sun stays unusually active, most of that daily energy increase will stil be in the much longer residence time of the oceans at those depths, until eventually that energy reaches an equalibrium within a far greater heat sink. And for a long time that large raised heat sink, will affect the atmosphere.
Each wavelength of incoming TSI has a different residence time within the atmosphere, land and ocean. This residence time is of course affected by it own inherent properties as well as all of the material it encounters. Then my own little physics law…”Only two things can effect the energy content of any system in a radiative balance. Either a change in the input, or a change in the “residence time” of some aspect of those energies within the system.”
Every year in January the earth is recieving 7% more insolation, then in June. yet the earth’s atmosphere is cooler, despite recieving more insolation. However I think it likely the earth is heating up at this time. Yes, it is losing some of that additional energy from albedo in the NH. But it is absorbing, day by day more intense and direct energy into an area that is mostly ocean. The SH is almost all ocean, and the atmosphere is losing much of that eneregy, not to space, but into the oceans.
All forcing are not the same. All feedbacks are not the same to all forcings.
Theo Goodwin says: “Most forcings are unknown….”
That’s a very strange thing to say. If they are unknown, how do you know they outnumber known forcings? JP
Jimbo says:
April 11, 2013 at 4:20 pm
richard telford says:
April 11, 2013 at 7:26 am
…………..
This list shows that there are warm events in the low southern latitudes. It does not show that they are synchronous, and it does not show that they are synchronous with the North Atlantic MWP.
Sorry richard if I read this all wrong but what does the following present? It is actually one of the references above. Here is the summary.
##################
Synchronous behaviour during the deglaciation, 11 thousand years ago, for Greenland and part of Antarctica is not evidence that the MCA was global.
Equally, synchronous behaviour on Milankovitch time scales is not evidence that behaviour should be synchronous on sub-Milankovitch time scales.
Please ignore, or moderators erase, my post at David says: April 11, 2013 at 9:44 pm. I was very tired and expressed very poorly.
Here are the same thoughts and questions, better articulated.
It is apparent that Steve Mosher and the climate science community consider all forcings to be the same, IE, two W/m2 increase of solar insolation, is the same as two W/m2 back radiation due to CO2. I find this quite astounding, even ignoring the herd of donkey assumptions with regard to the CO2 forcing.
Presuming those two forcing both happen at the same time, they will not have the same affect, as they travel different roads. The CO2 is likely to, at best, delay the timing of the evening low. The earth continues to radiatively cool through the night, by the time of sunrise most all that extra energy has left the atmosphere. Certainly most of it has.
However, 1% of the insolation, which penetrates into the ocean to a depth from 200 to 800 feet, none of that 1% energy has left the earth, and tomorrow and for the next dozen years, or more, if the sun stays unusually active, most of that daily energy increase will still be in the much longer residence time of the oceans at those depths, until eventually that energy reaches an equilibrium within a far greater heat sink. And for a long time that large raised heat sink, will affect the atmosphere.
Each wavelength of incoming TSI has a different residence time within the atmosphere, land and ocean. This residence time is of course affected by it own inherent properties as well as all of the material it encounters. Then my own little physics law…”Only two things can effect the energy content of any system in a radiative balance. Either a change in the input, or a change in the “residence time” of some aspect of those energies within the system.”
Every year in January the earth is receiving 7% more insolation, then in June. yet the earth’s atmosphere is cooler, despite receiving more insolation. However, I think it likely the earth is heating up at this time. Yes, it is losing some of that additional energy from albedo in the N.H. But it is absorbing, day by day, more intense and direct energy into an area that is mostly ocean. The S.H. is almost all ocean, and the atmosphere is losing much of that energy, not to space, but into the oceans! Some of that change in energy input at times of increased solar activity, which can last decades, has a very long residence time, some of it days, some of it week, some of it years , decades, and some of it centuries. It is a continues accumalation every day, so that over hundreds of days, a small change , becomnes quite large.
It therefore follows that any effect which increases the residence time of LW energy in the atmosphere, W/V for instance, but reduces the input of SW energy entering the oceans, causes a net reduction in the earth’s energy balance, proportioned to the energy change involved
relative to the residence time of the radiations involved.
All forcing are not the same. All feedbacks also are not the same to all forcings.
@ur momisugly Edohiguma.
I have pointed out before that there were Greek and Roman novels written before Hikari Genji. Why do you repeat “in Japan the first novel of mankind was written”?
E.M. Smith just posted a report about many changes and warmer periods during the last 10,000 years from the study of peat.
http://chiefio.wordpress.com/2013/04/12/oh-for-the-love-of-peat/
richard telford , my bad. Next time I should read. 🙂 Now check these I did read. 🙂
Imagine what papers we would get if governments started funding to the tune of billions research to find that the Medieval Warm Period was synchronous. You see, most climate scientists are looking for what their paymasters want.
Read the following as a whole.
And we have reported on September 7, 2011
Dear Richard Verney,
for the love of a merciful god PLEASE spellcheck your comments before posting!
Thank you.
David says:
April 11, 2013 at 9:44 pm
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Don’t over look that solar can penetrate the oceans to depth and therefore can heat the oceans.
DWLWIR, on the otherhand, can at best penetrate the ocean by about 10 microns and cannot effectively heat the oceans. If DWLWIR has sensible energy and can perform sensible work in the ocean environ, it would appear that it merely contributes towards driving evaporation and thereby helping to cool the very top surface layer of the ocean.
David says:
April 11, 2013 at 9:44 pm
It is apparent that Steve Mosher and the climate science community conside all forcings to be the same, IE, two watts per sq’M of solar increase, is the same as two watts per sq’M back radiation due to CO2.
—————–
Yes, which leads me to a strange question that never occurred to me before:
CO2 by itself is a fairly insignificant factor; this is not a controversial statement I believe. If all forcings are the same and are anonymous, does this mean that the expected positive feedbacks (I.E., increase in water vapor enhancing the greenhouse effect due to CO2) should happen for any and every increase in forcing equivalent to the increase in forcing due to CO2?
***
richard telford says:
April 11, 2013 at 11:05 pm
Synchronous behaviour during the deglaciation, 11 thousand years ago, for Greenland and part of Antarctica is not evidence that the MCA was global.
Equally, synchronous behaviour on Milankovitch time scales is not evidence that behaviour should be synchronous on sub-Milankovitch time scales.
***
Oh, right, they all perfectly cancel each other out to form a straight handle, until, of course the last 100 yrs, which forms the hockey blade…..
Hi:
That the MWP was global or nearly so has been well established for quite a long time – the kind of work reported here amounts to little more than a rebuttal to the MWP denialists.
The more important task, I think, is to ask the warmists the obvious corolary questions: if the polar bear didn’t evolve in about 300 years, then why does global warming now spell its extinction? i.e. do they prefer to deny evolution, the MWP, or their own hype? SImilarly, why didn’t the Thames, Yangtze, and other estuaries flood during the MWP? Canada’s PEI was above water during the period, so was what is now Manhatten. So what do the warmists want to deny? their own threat visions? the MWP? or history and geology?
Jimbo says:
April 12, 2013 at 5:08 am
Dmitri Mauquoy et. al. – 2004
Late Holocene climatic changes in Tierra del Fuego based on multiproxy analyses of peat deposits
“…..Our reconstruction for warm/dry conditions between ca. A.D. 960–1020 closely agrees with Northern Hemisphere tree-ring evidence for the MWP and shows that the MWP was possibly synchronous in both hemispheres, as suggested by Villalba (1994)……”
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The plant macrofossil data shown here is a measure of bog surface wetness. As the study was not replicated, it is difficult to know if the patterns are climatically driven or just due to inherent bog variability. It is easy to make a link between surface wetness and precipitation, the link to temperature is more tenuous.
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Chris S. M. Turney et. al. – 2004
Millennial and orbital variations of El Niño/Southern Oscillation and high-latitude climate in the last glacial period
http://www.nature.com/nature/journal/v428/n6980/abs/nature02386.html
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This paper shows that Dansgaard–Oeschger events, large temperature excursions in Greenland during the last glacial period, correlate with dry events in Australia, because of changes in ENSO activity. This paper is of minimal relevance to the Holocene, and as it does not reconstruct Australian temperatures, reveals nothing about the global extent of temperature changes associated with D-O events.
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LIU Yu et. al. 2011
Amplitudes, rates, periodicities and causes of temperature variations in the past 2485 years and future trends over the central-eastern Tibetan Plateau
“The results showed that extreme climatic events on the Plateau, such as the Medieval Warm Period, Little Ice Age and 20th Century Warming appeared synchronously with those in other places worldwide………..the mean temperature of the late Eastern Jin Event (2.67°C) was the highest in the 2485 years, even exceeding that of the second half of the 20th century (2.57°C)…..”
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This treering based temperature reconstruction presents some evidence that MCA in Tibet is synchronous with the MCA in Greenland. The paper offers no evidence of a globally synchronous MCA.
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New paper shows Earth was significantly hotter during past several thousand years
“…..finding that both were present in the Northern and Southern Hemispheres and were relatively synchronous……”
http://hockeyschtick.blogspot.com/2011/09/new-paper-shows-earth-was-significantly.html
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Ljungqvist (2011) is basically a hybrid of Marcott et al. (2013) and Osborn and Briffa (2006) The evidence in this paper for synchronous temperature changes in the Northern and Southern hemispheres is weak (at least in part because of the paucity of data from the south). The paper mentions the MCA only in passing.
Most of these papers offer zero evidence of a globally synchronous MCA. One presents very weak evidence. You need to critique the papers you read more effectively.
Mark Bofill says:
The water vapor feedback occurs in response to any warming by any forcing. In fact, some of the strongest evidence in support of the water vapor feedback acting approximately as modeled is from looking at the response of water vapor to the various temperature fluctuations such as those produced by ENSO.
It is only AGW skeptics who seem to believe that some forcings (those that are not anthropogenic, like solar) magically get magnified while forcings that they do not like do not get magnified. Strangely enough, these same people also seem to labor under the misconception that climate models treat CO2 forcings different from other forcings (as your post seems to sort of imply).
Thanks Joel. I wasn’t trying to imply anything though, I was merely asking.
Please don’t confuse Steven Mosher with the climate science community,
Steven Mosher, B.A. Philosophy and English, Northwestern University (1981); Director of Operations Research/Foreign Military Sales & Marketing, Northrop Aircraft Northrop Aircraft (1985-1990); Vice President of “Engineering” [Marketing], Eidetics International (1990-1993); Director of Marketing, Kubota Graphics Company (1993-1994); Vice President of Sales & Marketing, Criterion Software (1994-1995); Vice President of Emerging Technology [Marketing], Creative Labs (1995-2006); Marketing, Openmoko (2007-2009); Marketing Consultant, Qi Hardware Inc. (2009); Marketing Consultant (2010-Present); [Marketing] Advisor, RedZu Online Dating Service (2012-Present)
Mark Bofill says:
April 12, 2013 at 6:33 am
David says:
April 12, 2013 at 4:27 pm
It is apparent that Steve Mosher and the climate science community consider all forcings to be the same, IE, two W/m2 increase of solar insolation, is the same as two W/m2 back radiation due to CO2. I find this quite astounding, even ignoring…
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Yes, which leads me to a strange question that never occurred to me before:
CO2 by itself is a fairly insignificant factor; this is not a controversial statement I believe. If all forcings are the same and are anonymous, does this mean that the expected positive feedbacks (I.E., increase in water vapor enhancing the greenhouse effect due to CO2) should happen for any and every increase in forcing equivalent to the increase in forcing due to CO2?
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Mark, I do not know how else to interpret Steve Mosher’s comment…”Bottomline: the bigger the swing between the MWP and the LIA, the HIGHER the sensitivity.
The bigger the swing in natural oscillations the higher our risk from anthro forcing.”
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The key summation aginst this is my assertion….…”Only two things can effect the energy content of any system in a radiative balance. Either a change in the input, or a change in the “residence time” of some aspect of those energies within the system.”
Most people do not stop and consider that statement as a key to understanding energy systems. Each input into the earths’s system (Land, ocean, & atmosphere) encounters different properties, based on the materials that energy contacts. A certain wave length of SW energy is reflected back to space by clouds, the equivalent energy, in a different vibrational frequency, can penetrate up to 800′ into the ocean, and remain within the earth’s system for centuries.
Every change in input into the earths energy system causing a net change in the earth’s energy balance, must be evaluated according to the energy change involved, RELATIVE TO THE RESIDENCE TIME OF SAID ENERGY of the radiations involved. Different vibrational wave lenghts, travel different roads, each one having a different RESIDENCE TIME depending on the materials said energy encounters. This appears to me to be incontrovertabl true, and I do not know how some miss this.
Traffic on a road is a very good analogy to describe the different affect of an equal W/m2 change to any system in a radiative balance…
1. On a empty highway if ten cars per hour begin to continuesly enter the highway, and the cars are on the road for ten hours before exiting, there will be 100 cars on the road and as long as these factors remain the same the system is in balance. If you change the INPUT to eleven cars per hour, then over a ten hour period the system will increase from 100 cars to 110 cars before a balance is restored and no further increase occurs. The same effect as the increase in INPUT achieves can be realized by either slowing the cars down 10% or by lengthening the road 10%. In either case you have increased the energy in the system by ten percent by either increasing the residence time or the input.
2. Now lets us take the case of a very slow or long road with the same input. Ten cars per hour input, 1000 hours on the road, now you have ten thousand cars on the road. Now lets us increase the input to eleven cars per hour just as we did on the road with a ten hour residence time. Over a 1,000 hour period we have the same 10% increase in cars (energy) How ever, due to the greater capacity on that road, the cars (energy) have increased 100 times relative to the 10 hour road with a 10% increase in input. (1,000 car increase verses a 10 car increase.) Any change in the input or the residence time in this 1,000 hour road will have a 100 times greater effect then on the 10 hour road if the input change endures for 1,000 hours. The ocean of course is the 1000 hour road, the atmosphere is the 10 hour road.
Those that assume all inputs into the system have the same senstivity are simply wrong.
richard verney says:
April 12, 2013 at 5:55 am
David says:
April 11, 2013 at 9:44 pm
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Don’t over look that solar can penetrate the oceans to depth and therefore can heat the oceans.
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Thanks Richard, and I think I coverd that as it was directly referred to in my comment. Joel Shore appears to think that all forcings are the same, and W/V will be affected equally by any two forcings, just the same. Joel stated …”The water vapor feedback occurs in response to any warming by any forcing.”
Let us assume two equal W/m2 forcing changes, one in the spectrum of the sun which is reflected by clouds, one in the spectrum which most effectively by passes clouds. The first one has a fairly short residence time in the earth, as it is reflected back to space, and it does not increase W/V in the system. The next one strikes for more of the srface, including the ocean, where it by passes most of the top surface, and resides deeper in the ocean. This very slowly increases W/V. Now take a third change to the surface, that of LWIR. It is entirely absorbed in the very top of the ocean surface, and most of that energy is converted to latent heat of evaporation, IE w/v.
Now we must quantify what that W/V does. Any increase in water vapor is in and of itself a spectral modification of incoming TSI, reducing SW radiation at the surface, which we all agree is the primary mechanism which heats the ocean below the surface. The amounts of that TSI energy taken out by O2, O3, and primarily H2O, which absorbs in the visible and near IR, causes perhaps 20% of the total solar energy to be captured by water VAPOR (clear sky) clouds are an additional loss over and above that!
In an old John Daly article there was a comparison of two earths, one all ocean, one all land. A factor not discussed was how quickly would each earth reach their equilibrium temperature. Now for this assume two earths with no sun. One is again land, the other frozen ocean. Now a sun like ours magically appears. The land earth very quickly reaches its radiative balance. The ocean earth takes far longer, perhaps 1,000 times longer, but eventually its atmospheric mean temperature is warmer then the land earth due to the immensely greater energy within it coming from the oceans keeping the planet warm at night.
The summary to all this is really very simple. Whatever controls the energy content of the ocean on such a planet as our earth is the primary driver of climate. And the answer is SWR from the sun, either increasing or decreasing at the ocean surface, is the primary driver of our planets energy budget. To assume that a small effect which barely increases the LWR in the atmosphere, at the expense of a reduction in SWR entering the oceans, controls the climate and earths energy budget, is to claim that a small puff of wind can reverse the direction of an ocean liner under throttle. It is changes in the Sun’s vibrational wave length, even if TSI remains about the same, affecting changes in cloud cover and location, that primarily affect how much or how little SWR enters the ocean. I remember seeing an early IPCC chart stating that both cloud formation and the oceans are poorly understood.
This admission alone stops CAGW in its tracks, but I doubt the IPCC would repeat that statement today.