New paper: “unlikely that man-made global warming would cause a permanent El Niño state”

From the UK another paper with some pragmatic analysis, coupled with some rhetoric on sea ice:
http://noc.ac.uk/sites/all/themes/noc/images/logoPrint.gif

Arctic climate variation under ancient greenhouse conditions

Tiny organisms preserved in marine sediments hold clues about Arctic climate variation during an ancient episode of greenhouse warming.

Based on reconstructions of Arctic climate variability in the greenhouse world of the Late Cretaceous, Southampton scientists have concluded that man-made global warming probably would not greatly change the climatic influence associated with natural modes of inter-annual climate variability such as the  El Niño – Southern Oscillation (ENSO) or the Arctic Oscillation/ North Atlantic Oscillation (AO/ NAO).

“Even in the warm Cretaceous period, the patterns of these climatic oscillations changed over longer decadal timescales,” explained Professor Alan Kemp of the University of Southampton’s School of Ocean and Earth Science based at the National Oceanography Centre, Southampton. “It is therefore difficult to predict whether anthropogenically driven warming will lead to systematic changes such as persistently milder European winters (a positive AO/ NAO) as some have suggested.”

It is anticipated that the Arctic Ocean will become ice free during the summer within the next 15–50 years as a result of global warming. Because sea ice is reflective, its loss will reduce the amount of the Sun’s energy bounced back out to space, thereby amplifying regional warming. However, changes in atmospheric circulation could also occur, making it difficult to unravel the likely net effect on climate.

“A key question is how an Arctic without permanent ice cover will affect atmospheric circulation and climate variability, particularly over high and mid latitudes,” said Kemp.

One way of addressing this issue is to look back at previous greenhouse episodes in Earth’s history. For example, Kemp’s group has previously reported in the journal Nature that during the Late Cretaceous, when the dinosaurs roamed the world, the Arctic Ocean was free of ice in summer with only intermittent sea ice in the winter.

“Understanding Late Cretaceous climate should inform debate about future climate trends and variability under greenhouse conditions,” said Kemp, whose team’s new findings are published in Geophysical Research Letters.

In both studies, Kemp and his collaborators analysed sediment cores from a marine ridge in the Arctic Ocean. These sediments date to the Late Cretaceous (69–76 million years ago) and contain fossil remains of diatoms, an important group of phytoplankton – tiny planktonic marine plants.

The sediments contain alternating band-like laminae of two types, representing diatom growth conditions in the Arctic spring and summer, respectively. Each year is represented by a couplet of laminae, one of each type, which allowed the researchers to reconstruct ocean conditions at annual resolution.

The Cretaceous diatom Stephanopyxis.

The Cretaceous diatom Stephanopyxis.

“The presence of diatom laminae testify to ice-free Arctic summers during the Late Cretaceous, although there is also evidence of ice rafting by intermittent winter ice,” said Kemp.

The researchers analysed two sections of sediment core covering between them a continuous period of around 1,000 years. By analysing the characteristics of the diatom laminae and measuring their thickness they were able to reconstruct climate-driven variation in ocean conditions both between years and over decades.

Their analyses revealed that the Arctic climate of the Late Cretaceous varied over various timescales with periodicities closely matching those observed in the modern Arctic. It therefore appears that the Arctic was subject to some of the same climatic influences in the Late Cretaceous as it is today, including ENSO, which periodically transmits equatorial influences to high-latitudes via ocean-atmosphere interactions.

“A modern Arctic lacking permanent sea ice should be subject to similar influences as it was under greenhouse conditions in the Late Cretaceous,” said Kemp.

This is important because there has been an ongoing debate about whether natural modes of climate variability such as ENSO and AO/ NAO would be perturbed or enhanced by global warming caused by greenhouse gas emissions. Particular controversy has surrounded whether such warming could cause a permanent El Niño state or milder European winters.

“Based on our findings, it seems unlikely that man-made global warming would cause a permanent El Niño state,” concluded Kemp.

The researchers are Andrew Davies, Alan Kemp, and Heiko Pälike of the University of Southampton’s School of Ocean and Earth Science based at the National Oceanography Centre, Southampton.

The research was funded by the Natural Environment Research Council.

Publication:

Davies, A., Kemp, A. E. S. & Pälike, H. Tropical ocean-atmosphere controls on inter-annual climate variability in the Cretaceous Arctic. Geophysical Research Letters 38, L03706, (011). doi:10.1029/2010GL046151

Davies, A., Kemp, A. E. S. & Pyke, J. Late Cretaceous seasonal ocean variability from the Arctic. Nature 460, 254-258 (2009). doi:10.1038/nature08141

About these ads
This entry was posted in ENSO, Paleoclimatology, Sea ice and tagged , , , . Bookmark the permalink.

40 Responses to New paper: “unlikely that man-made global warming would cause a permanent El Niño state”

  1. vukcevic says:

    When El Nino (and ENSO, PDO, SOI) is concerned, most of the climate scientist behave like a blind man in a deep, deep dark room, trying to catch a black cat.
    Basically they have no idea.

  2. Latitude says:

    substitute Cretaceous, anthropogenically driven warming, etc….

    …with CO2 levels 2 to 8 times higher than present

  3. Manfred says:

    This would also support Bob Tisdale’s research.

    Blogger Tamino, however, should stop avoiding the scientific method and postulate speculations. such as:
    “Bob Tisdale (and others) simply can’t wrap their brains around the fact that global warming is the cause, not the effect, of much of the changes in N.Atl SST anomaly. Therefore global warming is the cause, not the effect, of much of the variation in the AMO.”

    http://wattsupwiththat.com/2011/02/03/tisdale-tasks-tamino/

    http://wattsupwiththat.com/2011/02/03/tisdale-tasks-tamino/

  4. Fraizer says:

    You mean it’s not worse than we thought?

  5. pat says:

    I suspect that Antarctica has a bit more to do with El Nino than the Arctic, and not only will it not be ice free in this geological epoch, but outside of the peninsula, there appears to be no warming at all.

  6. Anything is possible says:

    Haven’t these people ever heard of continental drift?

    The Earth was a very different place 65-70 million years ago. The Himalayas didn’t exist, the Atlantic Ocean was much smaller and Siberia and North America were much further apart. What effect would that have had on atmospheric and oceanic circulation?

    While these past re-constructions are interesting in themselves, to suggest that what may have happened 70 million years ago has any direct relevance to what may happen in the 21st. century is a huge stretch, and that’s putting it (very) politely.

  7. DJ says:

    Oh darn. Too late to include this research into the IPCC’s Fifth Assessment Report, so well just have to go with Tamino’s assessment of the AMO influence.

    What was that somebody said in a recent post about a little bitty tail wagging a great big dog??

  8. kwik says:

    I didn’t find any of the newspeak-keywords.

    Robust, unprecedented, unequivocal, ….hmmm….oh yes, concensus.

    Very refreshing.

  9. John Barrett says:

    There is also an interesting article about sea level rise in the Falklands where it was measuered at 0.75mm a year until the early 1980s. From 1992 it jumped to 2.5mm a year.

    http://noc.ac.uk/news/measuring-sea-level-rise-falklands

    The capital of the Falklands was discovered due to a dim-witted naval pilot called Stan, who couldn’t tell his right from left. He swung the ship to the right and crashed into a bay, whereupon the captain shouted at him “I said PORT, Stanley !”
    (That joke copyright Private Eye magazine 1982 )

  10. David Larsen says:

    The earth’s surface temperatures have oscillated since the dawn of time. Primarily a function of suns output in radiation on the earths external surface. During the aurignacian oscillations the oceans were at times 125 feet above what they are today. Caveman coal plants did not do that. The sun did.

  11. SSam says:

    In a section discussing the effects of continental drift on oceanic circulation, and the onset of the glaciation periods. Global Tectonics 3rd ed has this interesting nugget of info…

    The weathering of carbonates exposed on land, by
    a weak carbonic acid solution, formed by the dissociation
    of carbon dioxide from the atmosphere, or soil, in
    rainwater, produces calcium and bicarbonate ions that
    are then transported to the ocean by rivers. In the
    oceans the weathering reaction is reversed: calcium carbonate
    is secreted by organisms, to produce their tests,
    which, if preserved after the death of the organism,
    form carbonates on the sea floor.

    CaCO3 + CO2 + H2O ? Ca2+ + 2HCO3- (eq. 1)

    The carbon dioxide so released ultimately returns to
    the atmosphere. Thus the carbon fi xed in the carbonates
    on land is redeposited on the sea floor, with no net
    change in the CO2 content of the atmosphere. The
    weathering of silicate rocks by carbonic acid, however,
    has important differences. A simplified weathering reaction
    may be expressed as:

    Silicate mineral + 2CO2 + water [yeilds]
    2HCO3- + clay mineral + cation(s) (eq. 2)

    In the ocean the HCO3- ions combine with Ca2+, as
    in the reverse of equation 1, to form calcium carbonate.
    In this case, two molecules of CO2 are removed from
    the atmosphere, for every one molecule returned to the
    atmosphere when CaCO3 is formed in the ocean.
    Increased weathering of silicate rocks could, therefore,
    draw down the CO2 content of the atmosphere, and be
    a possible cause of global cooling (Raymo & Ruddiman,
    1992).

    As a result of the most recent phase of continental
    drift, the Cenozoic was characterized by a major
    episode of mountain building, notably throughout the
    Alpine–Himalayan belt, and culminating in the uplift
    of the Tibetan Plateau in the Late Cenozoic. The elevation
    of mountains would have greatly increased
    physical and chemical weathering processes, particularly
    as they concentrate rainfall on their windward
    flanks.

  12. Ian H says:

    Really this research is about looking at microfossils in marine sediments. That is what these guys do. But of course you can’t publish a paper that says simply “we looks at microfossils in marine sediments and we noticed some variation”. You need to hang some sort of justification and interpretation on this basic observation to get it into a journal.

    Providing evidence fo rthe effects of climate change used to be the great justifier of research of this type. Thousands of papers on all sorts of topics have been published with tenuous and contrived links to climate change used in order to justify the research.

    What I find interesting is that this paper uses the debunking of climate change to achieve the same effect. Two or three years ago I don’t think a paper like this would have been submitted. The world has changed.

  13. Alan Simpson not from Friends of the Earth says:

    This bit…

    “Based on reconstructions of Arctic climate variability in the greenhouse world of the Late Cretaceous, Southampton scientists have concluded that man-made global warming probably would not greatly change the climatic influence associated with natural modes of inter-annual climate variability such as the El Niño – Southern Oscillation (ENSO) or the Arctic Oscillation/ North Atlantic Oscillation (AO/ NAO).”

    That is the meat, the rest is rent seeking, but at least they were honest enough to write the quote above.

    Houses of cards falling, etc.

  14. eadler says:

    Ian H says:
    February 11, 2011 at 3:22 pm

    Really this research is about looking at microfossils in marine sediments. That is what these guys do. But of course you can’t publish a paper that says simply “we looks at microfossils in marine sediments and we noticed some variation”. You need to hang some sort of justification and interpretation on this basic observation to get it into a journal.

    Providing evidence fo rthe effects of climate change used to be the great justifier of research of this type. Thousands of papers on all sorts of topics have been published with tenuous and contrived links to climate change used in order to justify the research.

    What I find interesting is that this paper uses the debunking of climate change to achieve the same effect. Two or three years ago I don’t think a paper like this would have been submitted. The world has changed.

    I don’t see any evidence that they are” debunking climate change”. In fact, the author says:
    It is anticipated that the Arctic Ocean will become ice free during the summer within the next 15–50 years as a result of global warming. Because sea ice is reflective, its loss will reduce the amount of the Sun’s energy bounced back out to space, thereby amplifying regional warming. However, changes in atmospheric circulation could also occur, making it difficult to unravel the likely net effect on climate.

    “A key question is how an Arctic without permanent ice cover will affect atmospheric circulation and climate variability, particularly over high and mid latitudes,” said Kemp.

  15. Vincent Gray says:

    Where is this “Greenhouse World”? Perhaps we will soon see it next to Disney World ?

  16. Rational Debate says:

    They just have to keep on begging that question. Notice how ‘obviously’ any warming that occurred historically is “greenhouse” warming. Couldn’t possibly be any other cause, now could it? Doesn’t matter that often (most of the time?) CO2 levels lagged the temperature increases as best we can tell, cripes, that’s STILL greenhouse warming, ain’t it obvious? /sarc Just state it as if its a clear well established fact, and eventually all will believe (they need Obi Wan Kenobi wave of the hand mind control on a world wide scale I suppose). Brand any and all warming, Earth millions of years ago, Venus, you name it – clearly it’s greenhouse gas caused. Sheesh.

  17. R. Shearer says:

    Seems like it contains some propaganda. One doesn’t need to go so far back in time.

    http://wattsupwiththat.com/2010/09/08/inconvenient-ice-study-less-ice-in-the-arctic-ocean-6000-7000-years-ago/

  18. Arno Arrak says:

    Again we have “scientists” ignorant of what they talk about. A permanent El Nino state is an oxymoron because El Nino is a periodic phenomenon and has been ever since the Panamanian Seaway closed. It is part of ENSO, the El Nino – Southern Oscillation in the Pacific Ocean. ENSO is a physical oscillation of ocean water from shore to shore in the equatorial Pacific. It is comprised of warm El Nino and cool La Nina phases and one cycle takes four-five years to complete. There is no way to make it stand still which is what you would have to do to create a permanent El Nino state. Read “What Warming?” and find out the facts.

  19. Jimbo says:

    As recently covered on WUWT – it’s much worse than we thought.

    “Recovery mechanisms of Arctic summer sea ice”
    “Our results suggest that anomalous loss of Arctic sea ice during a single summer is reversible, as the ice–albedo feedback is alleviated by large-scale recovery mechanisms. Hence, hysteretic threshold behavior (or a “tipping point”) is unlikely to occur during the decline of Arctic summer sea-ice cover in the 21st century.”
    http://dx.doi.org/10.1029/2010GL045698

    See also:
    Ice free Arctic ocean during the Holocene ~10,000
    http://dx.doi.org/10.1016/j.quascirev.2010.08.016
    http://adsabs.harvard.edu/abs/2007AGUFMPP11A0203F
    http://geology.geoscienceworld.org/cgi/content/abstract/21/3/227

  20. Jimbo says:

    Eadler
    I don’t see any evidence that they are” debunking climate change”. In fact, the author says:
    “It is anticipated that the Arctic Ocean will become ice free during the summer within the next 15–50 years as a result of global warming.”

    The author most likely won’t be around in 50 years time. :>)

    Call me a sceptic if you like: :>)
    http://www.c3headlines.com/predictionsforecasts/

    Warmer Northern Hemisphere winters
    Colder Northern Hemisphere winters

    Earth’s rotation to slow down
    Earth’s rotation to speed up

    North Atlantic Ocean has become less salty
    North Atlantic Ocean has become more salty

    Avalanches may increase
    Avalanches may decrease

    Plants move uphill
    Plants move downhill

  21. peter_ga says:

    Fascinating stuff. The ice ages started 3 million years ago. One wonders if these oceanic oscillations started with them, or were always present. This suggests they were always there.

  22. P.G. Sharrow says:

    Too bad they had to add that AGW clap-trap. Now I don’t know if part of their paper is a lie or all of it is. pg

  23. Mike McMillan says:

    Each year is represented by a couplet of laminae, one of each type, which allowed the researchers to reconstruct ocean conditions at annual resolution.

    Annual resolution for conditions 65+ million years ago is pretty impressive. I wonder how closely they can date that particular 1000 year segment.

  24. JER0ME says:

    Firstly:

    Kemp’s group has previously reported in the journal Nature that during the Late Cretaceous, when the dinosaurs roamed the world, the Arctic Ocean was free of ice in summer with only intermittent sea ice in the winter.

    So how was this determined? Would that be by using a model perhaps? Or a time machine?

    Next, this idea of a permanent El Nino is one that is designed to frighten, or at least alarm. There is a cycle of El Nino, / La Nina. Predicting even the possibility of one without the other is ludicrous. It implies a state of constant warm water rising in the Pacific (as I understand it). That cannot continue forever, and there must be an opposite flow to return the warm water (or bring up cold water).

    Perhaps I have that wrong, or way to simple, but the idea seems to be that there would be some kind of permanent warming due to some fantasy of a cycle that doesn’t cycle any more. That is horse apples.

  25. Interestingly enough, there is no ~11 yr solar cycle signal in the data:
    http://www.leif.org/EOS/2010GL046151.pdf

  26. the_Butcher says:

    It is anticipated that the Arctic Ocean will become ice free during the summer within the next 15–50 years as a result of global warming.

    But according to Al Gore the ice is supposed to melt completely in 1-2 years from now.

  27. John Marshall says:

    In all probability the Medieval Warm Period also had an ice free Arctic especially during the summer. Greenland was settled then by the Vikings. WE are told that atmospheric CO2 levels were lower then than now!
    The end of the Cretaceous was warmer than today and CO2 levels were higher. But, during the Cretaceous there was CO2 sequestration into limestone and chalk in all seas of the planet so atmospheric CO2 levels were falling for the whole of that period and at a rapid rate. None of this points to CO2 as the driver for increasing temperatures.

  28. M White says:

    “It is anticipated that the Arctic Ocean will become ice free during the summer within the next 15–50 years as a result of global warming.”

    Without the anticipated changes a lot of time, effort and public money wasted for no good reason.

  29. Bill Illis says:

    The ENSO exists because the Pacific is big and its deep and it covers the equator.

    On a rotating planet with an atmosphere, there is always going to be a strong wind going in one direction at the equator which is going to push/pull/drag the surface water across the ocean to the other side. That movement of water will cause other ocean currents to set-up replacing the space left by the amount which is pushed/pulled/dragged across the ocean. An oscillation between warmer and cooler patterns will most likely develop. Even the Atlantic has an ENSO-like behaviour but it might be not big enough at the equator to create longer-lasting oscillations.

    The Pacific has been big and deep and covered the equator for about the past 400 million years. So that’s how long I think it has been there.

    It has been twice as big as it is now for most of that time so try and guess how big an El Nino got during Pangea when the Pacific covered 3/4 of the planet. At the end of equatorial region, where all the warm water got pushed to by the east-west wind, was the relatively-enclosed shallow Paleo-Tethys sea. The temperature in that ocean probably reached 45C at times which is too hot for most complex life-forms.

    http://www.scotese.com/images/255.jpg

  30. izen says:

    John Marshall says:
    February 12, 2011 at 1:33 am
    “In all probability the Medieval Warm Period also had an ice free Arctic especially during the summer. Greenland was settled then by the Vikings. ”

    If the Arctic was ice-free during the MWP th Vikings certainly didn’t report it. They were unsure if Greenland was an island or joined to Europe because they were unable to sail around it, or indeed any further north than Thule because of the ice present at the time. The ‘probability’ that the Arctic was ice free seems to be substantially lowered by the contemporary observations of the extent of ice.

    The Vikings first established a colony in Greenland in 985 AD.
    It had died out by 1400AD.
    The MWP for Greenland peaks around 950AD and the climate is COOLER than the present for most of the 2 centuries of Viking occupation according to most of the data I can find for this period.

    Perhaps you have a link for the temperature in Greenland during the Viking occupation that shows otherwise. Although the few reports written at the time about sailing conditions and ice extent would seem to confirm that it was colder than the present.

    When in your view was the peak of the MWP in Greenland, and how much cooling occurred during the Viking occupation ?

  31. izen says:

    While the fact that the ENSO cycles and other multi-decade climate cycles are detectable in ~60million yr old records when the geography of the continents was very different would seem to attest to the robustness of ENSO as an inherent feature of the global climate.
    But the absence of any sign of the 11/22 year solar cycles is more intriguing.
    Either the cycle was too small at that time to affect the climate, or it was at a different frequency than the present and may be represented in the 14 yr cycle detected.

    Has anybody got any thoughts on what this implies for studies of solar variability ?

  32. izen says:

    JER0ME says:
    February 11, 2011 at 10:56 pm

    Firstly:

    Kemp’s group has previously reported in the journal Nature that during the Late Cretaceous, when the dinosaurs roamed the world, the Arctic Ocean was free of ice in summer with only intermittent sea ice in the winter.

    So how was this determined? Would that be by using a model perhaps? Or a time machine?
    ================

    Neither models or a time machine are required.
    The types of diatoms that bloom in the spring Arctic with ice covered surface and open surface are different. And as explained in this research can be distigushed and case detectable banding in the sedimentary layers.

    The diatoms are the base of the food chain and have some importance for the commercial fishing industry because they determine fish types and abundance. For this reason the biology of diatoms in arctic waters is well researched for commercial reasons unassociated with climate. Diatom types in sediment are also extensively researched because of the implications they hold for the oil/gas industry.

    The application of that current knowledge to paleo-climate sediment analysis is just a bonus.

  33. Jeff K says:

    “One way of addressing this issue is to look back…” I nearly fell out of my chair reading that, imagine, taking the past into account when looking at conditions today-applies to people as well.

  34. Battery gal says:

    Speaking of ice melting, here’s another look at where the meltwater went (link at http://www.physorg.com/news/2011-02-view-climate.html)

    (PhysOrg.com) — Using new, high-resolution global ocean circulation models, University of Massachusetts Amherst geoscientist Alan Condron, with Peter Winsor at the University of Alaska, report this week that massive glacial meltwaters assumed to have flooded the entire North Atlantic 8,200 years ago, drastically cooling Europe, instead flowed thousands of miles further south. “These results dramatically affect our understanding of what causes climate change,” Condron says.

    If they’re correct and fresh water from glacial Lake Agassiz did end up in the Gulf Stream much farther south, between 20 and 40 degrees of latitude in the subtropical gyre, it’s revolutionary. “Basically, our model says that this flood ended up 3,000 miles further south than we all thought. It’s observed at the same time as the climate change and cooling in Europe, but the picture is far more complicated and different than we’d assumed. We all thought it went much further north.”

  35. tty says:

    The most significant thing about this research is probably that it further strengthens the evidence that even under the extreme greenhouse conditions of the Cretaceous there was winter sea-ice in the Arctic and major inland Ice-caps in Antarctica.
    Perhaps the Earth has never ever been completely ice-free.

  36. phlogiston says:

    Bill Illis says:
    February 12, 2011 at 4:22 am
    The ENSO exists because the Pacific is big and its deep and it covers the equator.

    On a rotating planet with an atmosphere, there is always going to be a strong wind going in one direction at the equator which is going to push/pull/drag the surface water across the ocean to the other side. That movement of water will cause other ocean currents to set-up replacing the space left by the amount which is pushed/pulled/dragged across the ocean. An oscillation between warmer and cooler patterns will most likely develop.

    izen says:
    February 12, 2011 at 5:11 am
    While the fact that the ENSO cycles and other multi-decade climate cycles are detectable in ~60million yr old records when the geography of the continents was very different would seem to attest to the robustness of ENSO as an inherent feature of the global climate.
    But the absence of any sign of the 11/22 year solar cycles is more intriguing.
    Either the cycle was too small at that time to affect the climate, or it was at a different frequency than the present and may be represented in the 14 yr cycle detected.

    ENSO could be a nonlinear oscillator, displaying intrinsic oscillation arising from its dynamic set-up. In a recent post:

    http://wattsupwiththat.com/2011/01/25/is-the-enso-a-nonlinear-oscillator-of-the-belousov-zhabotinsky-reaction-type/

    I suggested that the Pacific might behave like an excitable medium on account of the potential for time-limited positive feedbacks between upwelling and trade winds.

    Trying to create a scenario for oscillation in essentially linear dynamic terms may be cumbersome. Thus the BZ-type nonlinear oscillator paradigm seems compelling, but it does require an excitable medium. The intermittent and irregular nature of the ENSO suggests that – if it is behaving as a nonlinear oscillator – then it only doing so intermittently. Or that, as outlined in the post, it is a weakly periodically forced oscillator with a complex or relationship between forcing and response frequencies.

    As for the relation to the solar periodicity (or lack thereof) as Izen commented, the multi-decadal time course of ENSO could either mean that it is weakly and intermittently forced by any one of the many different solar periodicities (of which the 11/22 year is only the shortest), or indeed that the ENSO is an unforced oscillator, and that 60 odd years is its own intrinsic frequency.

  37. rbateman says:

    Anything is possible says:
    February 11, 2011 at 2:06 pm
    Haven’t these people ever heard of continental drift?

    The Earth was a very different place 65-70 million years ago.

    Don’t know about that, but 26 million years ago, the flora of the Sierras was much the same as it is today. A visiting geologist from UC Berkeley sampled the preserved pine needles, alder leaves and carbonized wood we found in the White Channel of the Ruby Mine, CA. The ash overlaying was Andesitic (looks like chocolate when wet) and came down before the last tilting of the Granodiorite Batholith of the Sierra Nevada. At the time of preservation, the CO2 levels were twice that of today (>750ppm) and the temperature was approx 3C higher, but the trees didn’t seem to notice.

  38. Bob Tisdale says:

    phlogiston says: “I suggested that the Pacific might behave like an excitable medium on account of the potential for time-limited positive feedbacks between upwelling and trade winds.”

    I believe the positive feedback you are referring to was first described by Jacob Bjerknes in the 1960s or 1970s and is known as “Bjerknes [positive] feedback.”

    Regards

  39. phlogiston says:

    Bob Tisdale says:
    February 13, 2011 at 9:03 am

    Thanks Bob, I’ll look up Bjerknes feedback.
    Best,
    Phil.

  40. Gabriel Atega says:

    The oscillations have long been in existence, even before the industrial revolution, and even before that time. The difference between aphelion and perihelion of the Earth’s revolve around the Sun is some 4 million miles. The Earth’s diameter is only some 8 thousand miles, yet the difference is dramatic when we compare the poles to the tropics. There are many variables that bring the planet to hot and cold.

    And there seems to be a direct correlation with ENSO and sunspots regularly occurring with Jupiter’s approach and distancing from the Sun during Jupiter’s aphelion and perihelion. Against these variables scientists are arguing that 350 ppm of CO2 rising to 400 ppm will be the driver or knob to warm the planet’s atmosphere.

    Thermodynamics cannot support the CO2 theory.

    The scientists are in a better position to understand why the weather is going crazy if they look instead at deforestation and its connection to the increase of water vapor in the atmosphere. Looking at the effects of deforestation on the absorption side of the carbon and hydrologic cycles, and placing it in context with the continuation of the retreat of the ice sheets from the last Ice Age up to the present time and until the planet returns to the next Thermal Maximum leading to the loss of the polar ice caps. We can be certain that as the planet continues its return to Thermal Maximum more and more water will go up to the atmosphere bringing about heavy floods and thick snow falls.

    One should wonder why water vapor is not taken into account and the loss of the forests are not as talked about as the increase in CO2 emissions from vehicles and the industries.

    It is now time to take account of all the variables not only on the emission side, but more so on the absorption side of the hydrologic and carbon cycles.

Comments are closed.