Matt Ridley: The mysterious cycles of ice ages

Posted: January 14, 2018 by oldbrew in Carbon cycle, Cycles, Ice ages, opinion
Tags: ,

US winter storm 2018 [image credit: NASA]

A sort of review of leading ice age theories. A paper by Ralph Ellis that was featured at the Talkshop gets a mention. A point not mentioned: the carbon cycle dictates that cooling leads to the oceans absorbing more CO2, while warming leads to more outgassing of it to the atmosphere.

Record cold in America has brought temperatures as low as minus 44C in North Dakota, frozen sharks in Massachusetts and iguanas falling from trees in Florida, writes Matt Ridley.

Al Gore blames global warming, citing one scientist to the effect that this is “exactly what we should expect from the climate crisis”. Others beg to differ: Kevin Trenberth, of America’s National Centre for Atmospheric Research, insists that “winter storms are a manifestation of winter, not climate change”.

Forty-five years ago a run of cold winters caused a “global cooling” scare.

“A global deterioration of the climate, by order of magnitude larger than any hitherto experienced by civilised mankind, is a very real possibility and indeed may be due very soon,” read a letter to President Nixon in 1972 from two scientists reporting the views of 42 “top” colleagues. “The cooling has natural causes and falls within the rank of the processes which caused the last ice age.” The administration replied that it was “seized of the matter”.

In the years that followed, newspapers, magazines and television documentaries rushed to sensationalise the coming ice age. The CIA reported a “growing consensus among leading climatologists that the world is undergoing a cooling trend”. The broadcaster Magnus Magnusson pronounced on a BBC Horizon episode that “unless we learn otherwise, it will be prudent to suppose that the next ice age could begin to bite at any time”.

Newsweek ran a cover story that read, in part: “The central fact is that, after three quarters of a century of extraordinarily mild conditions, the Earth seems to be cooling down. Meteorologists disagree about the cause and extent of the cooling trend, as well as over its specific impact on local weather conditions. But they are almost unanimous in the view that the trend will reduce agricultural productivity for the rest of the century.”

This alarm about global cooling has largely been forgotten in the age of global warming, but it has not entirely gone away. Valentina Zharkova of Northumbria University has suggested that a quiescent sun presages another Little Ice Age like that of 1300-1850. I’m not persuaded. Yet the argument that the world is slowly slipping back into a proper ice age after 10,000 years of balmy warmth is in essence true. Most interglacial periods, or times without large ice sheets, last about that long, and ice cores from Greenland show that each of the past three millennia was cooler than the one before.

However, those ice cores, and others from Antarctica, can now put our minds to rest. They reveal that interglacials start abruptly with sudden and rapid warming but end gradually with many thousands of years of slow and erratic cooling. They have also begun to clarify the cause. It is a story that reminds us how vulnerable our civilisation is. If we aspire to keep the show on the road for another 10,000 years, we will have to understand ice ages.

The oldest explanation for the coming and going of ice was based on carbon dioxide. In 1895 the Swede Svante Arrhenius, one of the scientists who first championed the greenhouse theory, suggested that the ice retreated because carbon dioxide levels rose, and advanced because they fell. If this were true, he thought, then industrial emissions could head off the next ice age.

Continued here.

  1. Ned Nikolov says:

    The cause of Ice Ages (and glacial-interglacial cycles of the Pleistocene in general) is still a mystery! In fact, if one removes CO2 as a driver of global temperature from climate models, these models become totally “helpless” in simulating the Ice Ages. Since we now have a solid evidence that atmospheric composition has no effect on planetary surface temperatures, let alone a trace gas like CO2 being a driver (Nikolov & Zeller 2017:, the paleo-climatology has no viable mechanism for explaining the Ice Ages at present …

  2. oldbrew says:

    Matt Ridley discussing the Ralph Ellis paper:

    The Antarctic ice cores, going back 800,000 years, then revealed that there were some great summers when the Milankovich wobbles should have produced an interglacial warming, but did not. To explain these “missing interglacials”, a recent paper in Geoscience Frontiers by Ralph Ellis and Michael Palmer argues we need carbon dioxide back on the stage, not as a greenhouse gas but as plant food.

    The argument goes like this. Colder oceans evaporate less moisture and rainfall decreases. At the depth of the last ice age, Africa suffered long mega-droughts; only small pockets of rainforest remained. Crucially, the longer an ice age lasts, the more carbon dioxide is dissolved in the cold oceans. When the level of carbon dioxide in the atmosphere drops below 200 parts per million (0.02 per cent), plants struggle to grow at all, especially at high altitudes. Deserts expand. Dust storms grow more frequent and larger. In the Antarctic ice cores, dust increased markedly whenever carbon dioxide levels got below 200 ppm. The dust would have begun to accumulate on the ice caps, especially those of Eurasia and North America, which were close to deserts. Next time a Milankovich great summer came along, and the ice caps began to melt, the ice would have grown dirtier and dirtier, years of deposited dust coming together as the ice shrank. The darker ice would have absorbed more heat from the sun and a runaway process of collapsing ice caps would have begun.
    – – –
    Less CO2 = more dust storms eventually, in this theory.

    See: Albedo regulation of Ice Ages, with no CO2 feedbacks

  3. oldbrew says:

    RE: ‘A point not mentioned: the carbon cycle dictates that cooling leads to the oceans absorbing more CO2, while warming leads to more outgassing of it to the atmosphere.’

    I just noticed Matt Ridley does mention CO2 and the oceans, but not the actual words ‘carbon cycle’.

    MR: Crucially, the longer an ice age lasts, the more carbon dioxide is dissolved in the cold oceans.

  4. Harry Newman says:

    Paleoclimate and the study of inter glacial cycles is particularly relevant to the current hysteria on anthropogenic climate change. The excellent articles by Javier on Judith Curry’s website are illuminating and establish a clear case for obliquity being one of the main drivers of the inter glacial cycles … and climate change.

  5. Jaime Jessop says:

    I think the trick here is not to ask what causes long-lived glacials, but to ask what are the circumstances whereby those glacials come to a brief end. I think, as things stand, mile thick glaciers stretching across northern land masses are the status quo, the equilibrium of the current climate state on planet earth. Interglacials are the exception to the rule and they do not tend to last long, relatively speaking. Without doubt, all interglacial inceptions are kicked off by Great Summers, when the 26k precessional cycle is at the point where insolation reaches a maximum at high northern latitudes. But not all Great Summers lead to interglacial inceptions and some Great Summers are weaker or stronger depending upon the 41,000 year obliquity cycle and the eccentricity cycle. The dust albedo/CO2 feedback theory is an attractive one and appears to fit the facts as to why not all insolation maxima trigger interglacial inceptions. Perhaps the more interesting question to ask – and the more relevant re. our present situation – is why some interglacials are longer or shorter in duration and how long it will be before the current Holocene interglacial draws to a close.

  6. p.g.sharrow says:

    By Jove! I do believe he’s got it!

    Once the snow fields last the Summer the die is cast and the Ice Mountains grow because of the extent warm Oceans and cooled air result in heavy snows. As the Oceans lower and cool the snows are reduced, but remain until the dust/dirt accumulates into enough thickness to support summer vegetation and summer warmth accumulation.Cold Dirt Muskeg turns into well watered grass lands and forest as the ice below melts from Geothermal heat from below. Remember Ice freezes from top down and melts from bottom up. Because of this, change of phase energy needed and it’s conductivity of energy, when the melt starts it goes out quickly…pg

  7. Ned Nikolov says:

    The albedo-dust theory cannot explain a key observation in the geological record of Ice Ages, i.e. the so-called polar amplification. This refers to the nearly doubled amount of cooling at the Poles during glacial maxima compared to the equatorial cooling. Polar amplification points to a whole different mechanism for explaining the Ice Ages… Can anyone guess what this mechanism might be?

  8. oldbrew says:

    This isn’t a guess at Ned N’s question, but might have some relevance?

    The Gulf Stream kept going during the last Ice Age
    Date: September 16, 2014
    Source: University of Tromso (Universitetet i Tromsø – UiT)

    The warm Atlantic water continued to flow into the icy Nordic seas during the coldest periods of the last Ice Age. An ice age may sound as a stable period of cold weather, but the name deceives. In the high latitudes of the Northern Hemisphere, the period was characterized by significant climate changes. Cold periods (stadials) switched abruptly to warmer periods (interstadials) and back.

    Quote from the link: So the air was getting colder, but the deep ocean water was getting warmer, during the coldest periods of the Ice Age. How is this possible?

    Clue: icebergs

  9. ren says:

    This is not the end of problems in North America with the polar vortex.

    The next year, North America will again have a severe winter, because the pattern of the polar vortex does not change, and solar activity will remain low until 2020.
    Does the 10-day forecast of the polar vortex foresee a change of circulation over North America?

  10. oldbrew says:

    The Wikipedia page for polar amplification says:
    In the extreme, the planet Venus is thought to have experienced a very large increase in greenhouse effect over its lifetime,[3] so much so that its poles have warmed sufficiently to render its surface temperature effectively isothermal (no difference between poles and equator).
    – – –
    But sadly for Wikipedia, this is far from true…

    ESA Finds a Frigid Surprise Hiding at Venus’ Poles
    Venus may be boiling hot, but its poles are very, very cold.

    By John Wenz | Published: Tuesday, April 19, 2016

    Thanks to a thick layer of cloud cover trapping in heat, Venus is the hottest planet in our solar system, with temperatures boiling over at 850 degrees Fahrenheit (454 C). But in a study published last week in Nature Physics, the European Space Agency found something surprising at the planet’s poles: temperatures more frigid than anywhere on Earth.

    Funny how that ‘thick layer of cloud cover trapping in heat’ fails so miserably to work at the poles 😉

  11. ren says:

    The current temperature (C) in the US.

  12. ren says:

    Oldbrew the layer of clouds now works on the Great Lakes.

    [reply] thanks ren [select temperature]

  13. ren says:

    Shown are two centers polar vortex in the lower stratosphere.

  14. oldbrew says:

    The Antarctic Centennial Oscillation: A Natural Paleoclimate Cycle in the Southern Hemisphere That Influences Global Temperature

    W. Jackson Davis 1,2,*, Peter J. Taylor 1 and W. Barton Davis 1
    1 Environmental Studies Institute, Santa Cruz, CA 95062, USA
    2 Division of Physical and Biological Sciences, University of California, Santa Cruz, CA 95064, USA
    * Correspondence:
    Received: 5 October 2017 / Accepted: 3 January 2018 / Published: 8 January 2018


  15. ren says:

    The pressure in North Dakota exceeds 1050 hPa.

  16. p.g.sharrow says:

    An observation: I once farmed small grains in the high mountain desert of northern California. It was remarkable how much climate changed with only 500 feet of elevation change Nearly 30 days of growing season length. A full climate zone of difference. About the same as moving 500 miles further north.
    Surface density altitude has a great deal to do with average thermal density, temperature, of the local. This is due to the insulating effect of the air above that reduces the night radiation loss into the night sky above. Radiation gains from the more intense day sunlight of the higher elevation were quickly lost as the sun angle went down. …pg

  17. ren says:

    The wave of arctic air moves towards the south-eastern US.

  18. BA2204 says:

    Ned, I would hazard a guess that frigid bottom water, dominated by Antarctica, is important cyclicly. The closure of circulation as South America moved and Central America arose could have finished the job. My home of NZ had tropical plants before that while further south. Now it is temperate. On a different tack – Maxwell also used the Poisson relationship in his Theory of Heat. Brett

  19. Paul Vaughan says:

    from OB’s link:
    “incorrect uniformity modeling of the atmosphere [of Venus]”

    incorrect uniformity modeling of everything

  20. Paul Vaughan says:

    on OB’s ACO link: message too long — concentrate 1 or 2 page max
    verbose administrative culture of red tape and delay is an EVASIVE substitute for quick potent truth

  21. ren says:

    The wave of the Arctic air moves to the southeast US. Visible atmospheric front.

  22. oldbrew says:

    Grab-a-headline time…

    IB Times: How to stop glaciers from melting? Build a giant wall around them, says Princeton scientist

    Michael Wolovick says large walls at the mouth of ice sheets in Greenland and Antarctica will effectively isolate them from the sea.
    January 15, 2018

    Data given by Wolovick shows that large walls at the mouth of ice sheets in Greenland and Antarctica will effectively isolate them from the sea. This could keep them in their frozen solid state longer and dramatically reduce the amount of ice that gets lost in the sea.

  23. ren says:

    Current temperature in North America.

  24. melitamegalithic says:

    On this subject I would add to Harry Newman above and recommend revisiting this piece from WUWT, particularly the comparisons of figure 3.

    Note the abrupt changes in the Holocene Max; those correspond to prehistoric events that are known.

    There is a questionable assumption by Milankovitch, based on the work of JN Stockwell. I am certain that Stockwell’s work is very incomplete.

    Tallbloke may be interested here, because of something I left as still an enigma, regarding block rotation of earth crust. Vide the new thinking below:

    The introduction of the second paper is enough.

  25. oldmanK says:

    The above comment went by another name. sorry.

  26. oldbrew says:

    Why an ice age occurs every 100,000 years: Climate and feedback effects explained
    Date: August 7, 2013
    Source: ETH Zurich

    Science has struggled to explain fully why an ice age occurs every 100,000 years. As researchers now demonstrate based on a computer simulation, not only do variations in insolation play a key role, but also the mutual influence of glaciated continents and climate.
    – – –
    From the abstract:
    The larger the ice sheet grows and extends towards lower latitudes, the smaller is the insolation required to make the mass balance negative. Therefore, once a large ice sheet is established, a moderate increase in insolation is sufficient to trigger a negative mass balance, leading to an almost complete retreat of the ice sheet within several thousand years.

    What is mass balance?

  27. ren says:

    I wonder when recently so much snow has fallen in Louisiana?

  28. Blob says:

    Funny how that ‘thick layer of cloud cover trapping in heat’ fails so miserably to work at the poles

    This temperature was estimated high up in the atmosphere, well above the tropopause:

    Here we report the first ever in situ observations of atmospheric waves in Venus’s thermosphere (130–140 km) at high latitudes (71.5°–79.0°). These measurements were made by the Venus Express Atmospheric Drag Experiment (VExADE)5 during aerobraking from 24 June to 11 July 2014. As the spacecraft flew through Venus’s atmosphere, deceleration by atmospheric drag was sufficient to obtain from accelerometer readings a total of 18 vertical density profiles. We infer an average temperature of T = 114 ± 23 K and find horizontal wave-like density perturbations and mean temperatures being modulated at a quasi-5-day period.

  29. oldmanK says:

    Some correlations in link. From wiki, wuwt and a paper “Glacier response to North Atlantic climate variability during the Holocene” N. L. Balascio1,2, W. J. D’Andrea1, and R. S. Bradley3 .

    In wuwt’s comparison I have added another two dates that are corroborated in other proxies. The 5200 BP in particular correlates with destructive events as evidenced in dated man-made structures. In both of the dates obliquity was nowhere near it is believed that it was (the evidence is increasing and last anomalies gone – what was anomaly is in fact additional evidence). Those jerks mean big trouble.


  30. oldbrew says: