Protecting Humanity from Ice Ages

ice ageI have recently become quite concerned about ice ages and the dangers they pose to humans on our planet — and indeed to most of terrestrial ecology.

I must confess I never much worried about the supposed dangers of global warming — even if we could rely on the predictions of IPCC climate models.  In fact, they seem to be failing miserably, as judged by the ongoing pause in GW — while atmospheric levels of anthropogenic CO2  and other greenhouse gases continue to increase.  It seems that our climate is mainly controlled by natural forcings, like solar activity and atmosphere-ocean oscillations that are not included in current models.

What drew my attention to ice ages is the manuscript (Climate and Collapse) by agricultural economist Dennis Avery, my coauthor on Unstoppable Global Warming: Every 1500 years [Rowman&Littlefield 2007].  Dennis documents the historic collapse of civilizations, using recorded history and archeological data.  Cold periods and droughts appear to be the main dangers to agriculturally based societies in all regions of the world.

There is no question here: To protect our civilization from harm, it is vitally important to understand the causes of severe climate cooling and try to figure out how to prevent such cooling episodes, if possible.

There are two kinds of ice ages; they are fundamentally different and therefore require different methods of mitigation: (i) Major (Milankovich-style) glaciations occur on a 100,000-year time-scale and are controlled astronomically.  (ii) “Little” ice ages were discovered in ice cores; they have been occurring on an approx. 1000-1500-yr cycle and are likely controlled by the Sun.  The current cycle’s cooling phase may be imminent — hence there may be urgent need for action.

Major glaciations — on a 100,000-year time scale

I recently published an essay on these pages on how to avoid the next major ice age; there have been nearly 20 such glaciations in the past two to three million years.  The coolings are quite severe: the most recent one, ending only about 12,000 years ago, covered much of North America and Europe with miles-thick continental ice sheets and led to the disappearance of (barely) surviving bands of Neanderthalers; they were displaced by the more adaptable Homo Sapiens.

According to the Serbian astronomer Milankovich, glaciation timing was controlled by astronomical parameters, such as oscillations, with a 100,000-year period, of the eccentricity of the Earth’s elliptic orbit around the Sun, oscillations with a period of 41,000 years of the Earth’s “obliquity” (inclination of the spin axis to the orbit plane, currently at around 23 degrees), and a precession of this spin axis, with a period of about 21,000 years.

While many consider the timing issue as settled, there are plenty of scientific puzzles still awaiting solutions: For example, how to explain the suddenness of de-glaciation, transiting within only centuries from a glaciation maximum into a warm Interglacial, like the present Holocene period.

Most expect the next glaciation to arrive rather soon; but calculations by Prof Andre Berger of the Catholic University of Louvain, Belgium, suggest a delay of up to 40,000 years — so there may be no great urgency.  Nevertheless, it would be useful and of great scientific interest to verify the existence of a hypothesized “trigger” that might be disabled by human action — at low cost and negligible risk.

Little Ice Ages (LIA) and the Dansgaard-Oeschger-Bond (D-O-B) cycles

After digesting hundreds of comments about my essay on stopping the next major ice age, I recognized the need to explain the existence also of “little” ice ages, which are likely of solar origin.  They occur quite apart from the major glaciations, have a cycle length of about 1000-1500 years, and demand different methods of mitigation.  They were discovered in Greenland ice cores by the Danish researcher Willi Dansgaard and by (Swiss scientist) Hans Oeschger, and further observed in ocean sediments by the late US geologist Gerard Bond [see Unstoppable Global Warming: Every 1500 years]

We don’t know what triggers an LIA, but suspect a strong correlation with a quiet Sun and prolonged absence of sunspots.  Experts in this field — Willie Soon (Harvard Observatory), Harjit Ahluwalia (University of New Mexico), Russian astronomer Habibullo Abdussamatov, the Hadley Centre in UK, and many others — believe that the next LIA is imminent.  The most recent LIA lasted from 1400 to 1830 AD — off and on.  It followed the Medieval Warm Period (MWP), when wine grapes grew in northern England and Norsemen were able to farm in southern Greenland.

The impact of the recent LIA was rather severe.  The Norse settlements were abandoned; indeed, Scandinavia was hardest hit.  Climatology pioneer Hubert Lamb documents crop failures, starvation, and disease in Europe, together with ice fairs on the frozen Thames.  During much of the American Revolution, New York Harbor was frozen over.  And we recall paintings of George Washington crossing the Delaware River, impeded by ice floes.

How to overcome an LIA

To avoid the huge human misery and economic damage, one would like to counteract the cooling phase of the D-O-B cycle — but how?  The next LIA may be only years away; but there is no obvious trigger for solar influence; our understanding of solar physics is limited by the rather short history of observation of the Sun.  While data on sunspots go back centuries, modern observations using spacecraft extend only for years.

An obvious scheme to counter a cooling is to make use of greenhouse (GH) warming.  However, carbon dioxide is not the answer: CO2 is limited in supply and is already mostly saturated — hence additional CO2 is not very effective.  Synthetics, like SF6, are too long lasting and may have risky side-effects.  The best answer may be water, but in the form of ice crystals; the scheme is easily tested and is transitory — reversible and incurring little risk. 

For a specific technical proposal see Saving Humanity from Catastrophic Global Cooling: A Task for Geo-Engineering:

Here is how I picture the operation — starting with a small feasibility test and validation of the theory:

A typical aerial-refueling aircraft can carry ~100 tons of water, which is to be injected as mist at the tropopause, at the bottom of the stratosphere, near an atmospheric temperature minimum.  To start, one might choose a surface density of water mist of 0.1 kg/m2, the area covered would be ~1km2.

Like contrails from aircraft, I expect some visible cirrus, which should disappear rapidly.  It would leave behind longer-lasting invisible cirrus, made up of ice crystals that are strong absorbers/emitters of infrared (IR) radiation, which covers also the atmospheric “IR-window” region of 8 to 12 microns — thus creating a major GH effect, and possibly even some detectable warming at the Earth’s surface.  Any satellite-borne IR-instrument should be able to track this emitter patch, measure its radiative climate forcing, and follow its spread and decay — whether days or months.

However, all this is based on theory and on calculations, which I published in 1988 in the peer-reviewed journal Meteorology and Atmospheric Physics.  Obviously, such predictions must be validated by direct observations.  Once the scheme is scientifically verified, operational planning for countering a possible cooling can take over.

As usual, there are many scientific questions that require answers — chiefly, understanding the physical mechanism that drives the D-O-B cycles; how to explain the size, shape, and duration of the abrupt quasi-periodic warmings and coolings.  Currently, there is a hot dispute about the synchronicity of the cycles between the two Polar Regions, revolving about the limited accuracy of ice-layer dating in Antarctic ice-cores.

While the science is certainly interesting and important, there is really no need to delay the crucial and urgent tests of geo-engineering, designed to validate a GH scheme of mitigation.  Such tests involve only minor costs and present negligible risk to the atmospheric environment.

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Comments (7)

  • Avatar

    Dan Pangburn


    Engineering science proves CO2 has no significant effect on climate. The proof and identification of the two factors that do cause reported climate change are at (now with 5-year running-average smoothing of measured average global temperature (AGT), the near-perfect explanation of AGT, R^2 = 0.97+ since before 1900). The ongoing average global temperature trend is down.

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      Absolutely correct Dan. But don’t expect the GHE, AAGW extremists to ever agree.

      They’re too bound up in their leftist philosophy to consider reason much less logic.

      Hitler was correct when he said that

      the masses of people do not reason
      like animals they are driven by fanaticism and hysteria

      The GHE, AAGW, climate change pigs are using Adolf Hitler’s thought to advance their position

      I hope they are proud.

      Everyone on the face of the earth should be denouncing them.
      The denunciation of them is not happening because of the


      who are for the destruction of civilization as we know it.

  • Avatar

    Charles Higley


    There is really no greenhouse effect based on gases. NO gas at any concentration in the atmosphere can heat Earth’s surface nor can a gas effectively convert IR radiation into heat in the air. During daytime, the absorption and emission of these gases are saturated and the effect is a wash, no change. It is during the night that these gases, more accurately called “radiative gases,” actively and unopposed, convert heat energy in the atmosphere to IR radiation which is then lost to space. “Greenhouse gases” cool the planet. This explains why the air chills so quickly right after sundown and local breezes kick up so quickly on a partly cloudy-sunny day; the air in shadow cools rapidly due to these gases.

    Nope, there is no detectable greenhouse effect. This is junk science cobbled up to push a political agenda. Their “science” claims that the greenhouse gases in the upper tropical troposphere (at -17 deg C) “traps” IR radiation and sends it to Earth’s surface (at 15 deg C). There is no way that a cold gas can warm a hot body by radiative or conductive contact. The idea violates thermodynamics at the most basic level.

    So, the warmists then conflate this mortal failure of their junk science (hoping the publics does not notice) with the concept that these gases can convert IR radiation directly into heat in the atmosphere. As stated above, in daylight, this effect is a wash and at night these gases serve to cool the atmosphere.

    Altering Earth’s atmosphere to avoid any kind of cold period is a non-starter. Sorry. Think about it. In direct sunlight, the planet with no atmosphere would be at about 123 deg C and with an atmosphere it is 15 deg C. Having an atmosphere COOLS the planet by adding conductive and convective energy transport where only radiative dispersion was possible with no atmosphere. I talk about daytime here because all computer climate models have daytime only; no night time allows them avoid the cooling that occurs at night.

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    I view any atmospheric geo-engineering as a bad idea, as it could go awry. We survived the last LIA, and through mitigation we can all survive the next. The only time I would deem this kind of geo-engineering as reasonable, would be in the face of a full blown ice age.

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    Gina Liggett


    This is a wonderful example of considering the full context of earth climate. The Climategaters are too bothered with protecting fragile egos to consider thise silly major and minor ice ages.

    You would think that people purportedly considered “climate scientists” would find this fascinating. But, ideology is their real motivator.

  • Avatar

    Charles Higley


    The author needs to realize that an ice age is a 12 million year period of multiple glaciations. We are due for the next glacial period and are only 2 million years into a 12 million year ice age. People keep conflating these terms, probably because the Little Ice Age is a misuse of “ice age.” It should be more like a “mini-glaciation.”

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      It’s also out of the range of the average life span. My grand parents farmed during the “dirty 30’s”, they would say todays climate is nothing to worry about.

      The LIA was not that long ago in geologic time scales , but way beyond most peoples experience. Might be why it’s so easy for alarmists to sell this fraud. Most people cannot remember last week.

      I can remember the 70’s global cooling alarmism. And know that a lot of the same people are promoting the CAGW scam.

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