Part 4 of 5
Part 1: Astronomical cycles
Part 2: Science, psychics, and myths
Part 3: Poleshifts and theosophy
Part 4: Climate change
1. The climate system
2. Climate and axial tilt
3. The climate record
Part 5: Appendices
Paul Davies underlines our limited understanding of the global climate as follows:
Most computer simulations of the Earth’s atmosphere predict some sort of runaway disaster, such as global glaciation, the boiling of the oceans, or wholesale incineration due to an overabundance of oxygen setting the world on fire. ... Yet somehow the integrative effect of many interlocking complex processes has maintained atmospheric stability in the face of large-scale changes and even during periods of cataclysmic disruption.1
Some of the chief factors influencing the climate are mentioned below:
1. The energy output of the sun. The radiation emitted by the sun varies in cycles of different lengths. The best-known one is the approximately 11-year sunspot cycle. The sun’s magnetic field reverses polarity during each cycle, and therefore returns to the same state every 22 years (known as the Hale cycle). Longer-term cycles include the approximately 870-year Gleissberg cycle and the 210-year Suess cycle. The Maunder Minimum (1645-1715) was a period when there were few or no sunspots and coincided with the coldest period of the Little Ice Age. Other periods with low sunspot activity, such as the Spörer Minimum (1420-1530) and the Dalton Minimum (1795-1825), also coincided with cooler periods. Changes in solar activity have also been linked to a 1500-year cycle of global warming and cooling. While total solar irradiance varies by only about 0.1% over a solar cycle, the figure is about 5% for solar ultraviolet energy and 3-20% for galactic cosmic rays. When the solar wind grows stronger, fewer cosmic rays reach the earth, and this may lead to less low-level cloud formation and therefore warmer temperatures.2
2. The geometry of the earth’s orbit, which determines the amount of
solar radiation reaching the earth’s outer atmosphere. The three main variables are:
a. The tilt of the earth’s axis, which determines how much solar radiation is received at different latitudes. A greater tilt amplifies seasonal cycles at high latitudes because the relative increase in solar radiation in the polar regions is higher than in the tropics. A change in tilt of 1º causes a 2.5% increase in summer insolation at 65ºN, a 1.2% increase at 45ºN, and an overall average increase of only 0.8% for the entire northern hemisphere, assuming an orbital eccentricity of 0.039.3
b. Climatic precession (the 21,000-year cycle resulting from the precession of the equinoxes combined with apsidal precession), which determines at what time of the year the earth is closest to and furthest from the sun. At present the earth is closest to the sun in northern-hemisphere midwinter, which means that winters in the northern hemisphere are less severe than they might otherwise be.
c. The ellipticity of the orbit (the degree of deviation from a circle, involving variations in the earth’s distance from the sun).4 The ellipticity is currently 0.017, and is thought to range from 0.005 (almost circular) to 0.058 over a period of approximately 100,000 years, mainly due to the gravitational effects of Jupiter and Saturn. The current orbital eccentricity means that incoming solar radiation in the northern-hemisphere winter is up to 6.8% higher than in the southern-hemisphere winter. When the orbit is at its most elliptical, the level of insolation at perihelion will be about 23% more than at aphelion. If the axial tilt was 0°, the present eccentricity would still produce an approximately 0.7°C variation in solar insolation over the course of a year.5
3. The transparency of the atmosphere to either incoming solar radiation or outgoing heat. Clouds are the most important factor reflecting solar radiation back into space. Another factor is the concentration of greenhouse gases in the atmosphere, such as water vapour, carbon dioxide, methane, nitrous oxide, and ozone. Another variable is the amount of aerosols (small particles) in the atmosphere, including dust thrown up by volcanic eruptions, and meteoric dust from space (resulting from passing through the tail of a comet, a meteorite stream, interstellar dust clouds, etc.).6 Sulphur dioxide from volcanic eruptions combines with water vapour to form tiny droplets of sulphuric acid, which reflect sunlight and lead to cooler temperatures in the lower atmosphere. Worldwide temperature dropped by about 2°C following the major volcanic eruption of Krakatoa in Indonesia in 1883. After the Tambora eruption in 1815, the extensive volcanic haze caused the following year to be called the ‘year without a summer’.
Paul LaViolette has proposed that a cosmic ray volley or galactic superwave, caused by explosions in the centre of our galaxy, can push large amounts of cosmic dust into the solar system. These dust incursions substantially alter the earth’s climate through their effect on the sun (perhaps triggering nova-like eruptions) and the transmission of solar radiation through space. He argues that galactic superwaves pass us about once every 26,000 +/- 3000 years (approximating a polar precessional cycle), with the possibility of a 13,000 year recurrence interval.7 Another important factor is that as the earth revolves around the centre of the galaxy, it oscillates up and down through the galactic plane in a cycle lasting over 80 million years. When it crosses the plane, it encounters higher concentrations of cosmic dust and debris. The sun is currently almost 100 light years above (north of) the galactic plane, and moving further away, and will return to it in about 27 million years. The moon is believed to play a role in modulating the influx of meteoric dust.8
4. Atmospheric and oceanic circulation patterns, which are set in motion by the different amounts of energy received from the sun at different latitudes and by the rotation of the earth. Atmosphere and ocean circulation reduces temperature imbalances on a regional scale as well as between high and low latitudes. There is still much to be learned about ocean oscillations, such as the El-Niño/Southern Oscillation (ENSO), Pacific Decadal Oscillation (PDO), and Atlantic Multidecadal Oscillation (AMO), and their connection with periods of warming and cooling.
5. The distribution of land and sea, and the topography of the continents and seafloor (land elevation, sill depth, channel width, etc.), which affect atmospheric and oceanic circulation patterns. Mountain building and continental plateau uplift, and the opening and closing of ocean gateways have a major impact on ocean circulation and heat transport; this is all the more true of the uplift or submergence of entire landmasses. Land temperatures reflect both elevation and proximity to the sea (which has a higher heat-storage capacity than land). The average annual temperature decreases by about 4°C for each 550-metre rise in altitude. Hence there is permanent snow on Mt. Kilimanjaro, despite the fact that it is located astride the equator. In the Atlantic, the Gulf Stream carries warm surface water northwards, and keeps northern Europe much warmer than Canada at the same latitude. Conversely, the cool Peruvian coastal current ameliorates the tropical climate of Chile and Peru. The Gulf Stream is thought to have been some 35% weaker during the last glacial maximum, some 21,000 years ago.9
The popular dogma of plate tectonics/continental drift is frequently invoked to explain past climates, but detailed studies show that shifting the continents succeeds at best in explaining local or regional palaeoclimatic features for a particular period, and invariably fails to explain the global climate for the same period. Moreover, drifters say that the continents have shifted little since the start of the Tertiary, yet this period has seen significant climate change. The geographic distribution of palaeoclimatic indicators such as evaporites, carbonate rocks, coals, and tillites (rocks formed from glacial deposits) is best explained by stable continents and by periodic changes in climate, from globally warm or hot to globally cool. For instance, 95% of all evaporites (a dry-climate indicator) from the Proterozoic to the present lie in regions that now receive less than 100 cm of rainfall per year, i.e. in today’s dry-wind belts. The evaporite and coal zones show a pronounced northward offset similar to today’s northward offset of the meteorological equator.10 Horizontal crustal movements are relatively unimportant climatically compared with vertical crustal movements and the associated emergence and submergence of continents.11
6. The albedo (reflectivity) of the earth’s surface (due to soil types, presence of ice, snow, and vegetation, etc.), which affects the earth’s absorption or radiation of energy.
7. Currents of electricity within the earth (telluric currents) and in the atmosphere, and variations in the geomagnetic field. Geomagnetic field patterns closely match the circulation patterns of the atmosphere and also affect ocean currents.12 F. Jueneman suggested that a sudden collapse of the magnetic field could cause the air to be chilled into a liquid rain or frozen into snowflakes, followed by super-hurricane winds rushing in to fill the atmospheric vacuum.13
8. The impact of asteroids, meteoroids, or comets of varying sizes. It is fashionable at present to assign impacts a major role in triggering climate change and global catastrophes. However, polar ice core studies show no evidence that the climatic transitions of the last ice age were precipitated by comet impacts, though cosmic bodies certainly hit the earth from time to time.14
9. Interactions between life and its environment. According to the Gaia hypothesis, the earth’s biota does not simply respond passively to climate but helps to modulate and even control it, by regulating the concentration of atmospheric carbon dioxide and other organically derived substances so as to keep temperature and precipitation at advantageous levels. James Lovelock describes the earth as a self-regulating organism, capable of ensuring the survival of a life-sustaining global climate. Humans, too, influence the climate, e.g. through land-use changes (such as urbanization and deforestation) and emissions of greenhouse gases and aerosols, but their impact is easily outweighed by natural factors.
According to the widely accepted Milankovitch model of the ice ages, the history of glaciation and deglaciation is primarily determined by the insolation changes resulting from the three orbital cycles – the obliquity cycle (i.e. the postulated axial oscillation between 22.1° and 24.5°) with a period of 41,000 years; climatic precession with periods of 23,000 and 19,000 years; and the eccentricity cycle with a period of approximately 100,000 years. It is commonly asserted that studies of the climate record have found evidence of climatic variations with essentially the same frequencies. However, the picture is rather more complicated than is often implied. The periodicities found in the Pleistocene climate record include: 140,000, 104,000, 100,000, 44,000, 43,000, 41,000, 40,000, 25,000 24,000, 23,400, 23,000, 20,000, 19,000, 18,600, 15,700, 9300, 9200, 6400, and 5700 years.15 Scientists often seem to be more interested in fitting data into the Milankovitch theory than in objectively testing it or examining alternatives.
Even if the approximately 41,000-year periodicity found in the climate record is genuine – and age determinations become increasingly uncertain the further back we go in time – it would be premature to conclude that this proves the existence of the obliquity cycle postulated by science, since other factors may be responsible. The general belief that the 100,000-year periodicity is related to the eccentricity cycle has also been challenged.16 LaViolette speculates that galactic superwaves may be related to the 23,000-year climatic cycle, and could also account for the 100,000-year cycle, which approximates four superwave periods.17 Muller & MacDonald proposed that this cycle is due to the periodic alteration in the angle between the ecliptic and the invariable plane of the solar system (which approximately coincides with the orbital plane of Jupiter), in which there is a concentration of dust and other debris; the inclination of the ecliptic in relation to the invariable plane is believed to oscillate between 0.8° and 2.6° over a period of about 100,000 years.18 However, this explanation has been criticized on the grounds that the earth’s orbital inclination with respect to the earth-crossing dust bands does not vary in a smooth periodic fashion.19
Alistair Dawson concluded that some of the late Quaternary palaeoclimatic data can certainly not be explained in terms of the Milankovitch cycles. He also warned that any correlations should be tempered with caution since the calibration between Milankovitch astronomical chronology and radiometric ages is not known with certainty, and it is not at all clear how Milankovitch effects are translated into changes in global climate.20 The uncertainties in the dating of ice cores are very great; the upper annual layers can be counted individually, but lower down various indirect dating methods have to be applied, which can lead to uncertainties of over 5000 years at depths of 400 metres or more; for comparison, a 3190-metre core drilled near Dome C in Antarctica is believed to represent an age of 800,000 years.21 A highly dubious practice is ‘astronomical tuning’, whereby periodicities found in palaeoclimate records (e.g. oxygen isotope values) are adjusted to match one or more of the orbital cycles, with radiometric or palaeomagnetic dates being used to anchor the timescale where available.22
The main problems facing the Milankovitch model are as follows.23 First, it fails to explain the vast epochs in which the earth was free of polar ice sheets. Second, the relatively small seasonal and latitudinal radiation variations resulting from the orbital parameters are insufficient to account for the magnitude of climatic changes. Third, the 100,000-year cycle dominates the palaeoclimate record for about the past 900,000 years, whereas the 41,000-year cycle was dominant in the period from 2.8 to 0.9 million years ago; the reason for this is unknown. Fourth, linking the 100,000-year cycle to eccentricity variations is problematic for the following reasons: orbital calculations show that eccentricity has cleanly resolved variations of about 95,000 and 125,000 years, but these do not show up in climate records; it is assumed that they combine into a 100,000-year cycle, but eccentricity variations on this timescale have the weakest effect on solar insolation of all the orbital factors; eccentricity variations have a strong 400,000-year cycle, but it is absent in most climate records. Fifth, the pattern of the climatic record is asymmetrical: ice ages appear to start slowly and take a long time to build up to maximum glaciation, only to terminate abruptly and go from maximum glacial to full interglacial conditions in less than 7000 years. Sixth, climatic changes in the northern and southern hemispheres appear to be synchronous, whereas the precession cycle operates in different directions in the two hemispheres. Seventh, the timing of the penultimate interglacial appears to have begun 10,000 years in advance of the solar forcing hypothesized to have caused it. Finally, solar flares have probably altered the amount of solar radiation received at the outer atmosphere, whereas the Milankovitch theory assumes that it has remained constant.
In theosophical literature poleshifts are mentioned as one of the causes of sudden climatic changes and ice ages. H.P. Blavatsky says that the ‘karmic disturbance of the axis’ has produced periodic deluges and glacial periods.24 W.Q. Judge writes:
Ice cataclysms come on not only from the sudden alteration of the poles but also from lowered temperature due to the alteration of the warm fluid currents in the sea and the hot magnetic currents in the earth, the first being known to science, the latter not. The lower stratum of moisture is suddenly frozen, and vast tracts of land covered in a night with many feet of ice. This can easily happen to the British Isles if the warm currents of the ocean are diverted from its shores.25
1. Paul Davies, The Cosmic Blueprint, Unwin, 1989, p. 132.
2. Climate change controversies, https://davidpratt.info.
3. Thomas M. Cronin, Paleoclimates: Understanding climate change past and present, Columbia University Press, 2010, p. 116.
4. Ellipticity (e) = 1 - b/a, where b is the length of the orbit’s minor axis (shortest diameter) and a is the length of its major axis (longest diameter). A circle therefore has an ellipticity of 0, because both axes are the same length. If the minor axis is 10% shorter than the major axis, the ellipticity is 0.1.
6. The entire atmosphere is permeated with meteoric dust and an estimated 20,000 to 40,000 tons of cosmic dust fall on the earth every year. According to theosophical literature, solar forces reaching the earth arouse electromagnetic currents in this thick shell of meteoric dust; the electromagnetic interchanges between the earth and its meteoric veil produce various meteorological phenomena, such as storms, lightning, winds, droughts, and the auroras, and are also responsible for some 70% of the earth’s heat. The associated expansions and contractions of the atmosphere are said to be linked to the succession of glacial and warm periods. See Earth’s meteoric veil, https://davidpratt.info.
7. Paul LaViolette, Earth Under Fire, Starlane Publications, 1997.
8. William R. Corliss (ed.), Science Frontiers, no. 100, Jul.-Aug. 1995, p. 3.
9. Jean-Claude Duplessy, ‘Climate and the Gulf Stream’, Nature, vol. 402, 1999, pp. 593-4.
10. See Palaeomagnetism, plate motion and polar wander (Palaeoclimate), https://davidpratt.info.
11. See Sunken continents versus continental drift, https://davidpratt.info.
12. John Gribbin, Future Weather, Penguin, 1982, pp. 154-68.
13. Frederic Jueneman, Raptures of the Deep, published by Research & Development Magazine, 1994/95, pp. 122, 127.
14. Earth Under Fire, p. 321. See also The great dinosaur extinction controversy, https://davidpratt.info.
15. ‘Geochronology’, Encyclopaedia Britannica CD98; A. Berger et al. (eds.), Milankovitch and Climate, Reidel, 1984.
16. W.S. Broecker, in Berger, op. cit., pp. 687-98.
17. Earth Under Fire, pp. 301-2.
18. R.A. Muller & G.J. MacDonald, ‘Spectrum of 100-kyr glacial cycle: orbital inclination, not eccentricity’, Proceedings of the National Academy of Sciences, USA, vol. 94, 1997, pp. 8329-34; B. Peucker-Ehrenbrink & B. Schmitz (eds.), Accretion of Extraterrestrial Matter Throughout Earth’s History, Kluwer Academic/Plenum Publishers, 2001, ch. 9.
19. Accretion of Extraterrestrial Matter Throughout Earth’s History, ch. 2; J.A. Rial, ‘Pacemaking the ice ages by frequency modulation of earth’s orbital eccentricity’, Science, vol. 285, 1999, pp. 564-8.
20. A.G. Dawson, Ice Age Earth, Routledge, 1992, pp. 247, 255.
22. Cronin, Paleoclimates, pp. 99, 102, 117, 119; E.W. Bolton, K.A. Maasch & J.M. Lilly, ‘A wavelet analysis of Plio-Pleistocene climate indicators: a new view of periodicity evolution’, Geophysical Research Letters, vol. 22, no. 20, 1995, pp. 2753-6. For problems with radiometric dating, see The age of earth, https://davidpratt.info.
23. W.S. Broecker, op cit.; Cronin, Paleoclimates, pp. 130-2; Muller & MacDonald, ‘Spectrum of 100-kyr glacial cycle: orbital inclination, not eccentricity’; en.wikipedia.org/wiki/Ice_age; en.wikipedia.org/wiki/Milankovitch_cycles.
24. H.P. Blavatsky, The Secret Doctrine, Theos. Univ. Press (TUP), 1977 (1888), 2:274, 144-5. Blavatsky quotes the following from an article by Henry Woodward in the Popular Science Review: ‘If it be necessary to call in extramundane causes to explain the great increase of ice at this glacial period, I would prefer the theory propounded by Dr. Robert Hooke in 1688; since, by Sir Richard Phillips and others; and lastly by Mr. Thomas Belt, C.E., F.G.S.; namely, a slight increase in the present obliquity of the ecliptic ...’ (SD 2:726).
25. W.Q. Judge, The Ocean of Theosophy, TUP, 1973 (1893), p. 140.
When the axial tilt increases, the summers in both hemispheres receive more solar insolation and winters less. Conversely, when the axial tilt decreases, summers receive less insolation and winters more. However, these changes are not of the same magnitude everywhere on earth. High latitudes experience an increase in the annual mean insolation with increasing axial tilt, while lower latitudes experience a reduction. Since a lower axial tilt reduces overall summer insolation and also reduces mean insolation at high latitude, it has been argued that it favours an ice age.2
The earth’s axial tilt divides it into three main climatic zones: the tropical or torrid zone, the temperate zones, and the polar or frigid zones. The tropical zone lies between the tropic of Cancer and the tropic of Capricorn, where the midday sun is vertically overhead at the summer and winter solstices respectively. The temperate zones lie between the tropics and the polar circles (23.4° and 66.6° N and S). Within these regions, the sun is never vertically overhead, and the intensity of insolation becomes increasingly seasonal with distance from the equator. At 50° latitude, there are just over 16 hours of daylight at the summer solstice, but only about 8 hours at the winter solstice. At 60° latitude, the figures are 19 hours and 6 hours respectively. In the polar zones, seasonality is taken to extremes. At the arctic and antarctic circles, there is a day of 24 hours’ daylight at the summer solstice and 24 hours’ darkness at the winter solstice. At 79° there are two months of permanent daylight during summer and two months of winter darkness. At the poles, there would be six months of daylight during the summer and six months of winter darkness, were it not for the fact that atmospheric refraction reduces the period of darkness by about half.
Although the earth’s tilt defines the theoretical boundaries of the tropical, temperate, and polar zones, actual climate conditions can differ significantly from this simple picture due to the influence of all the many other climatic factors, with ocean currents playing a particularly important role. Thus, although theoretically the temperate zones are the regions of the earth between the tropics and the polar circles, in terms of actual climatic conditions the temperate zone currently lies between about 40° and 50° in the northern hemisphere and 35° and 55° in the southern hemisphere. Moreover, not even these more restricted zones can be described as temperate in their entirety, since although the zone includes western Europe and similar regions such as New Zealand, it also includes continental heartlands, such as Siberia and the central-northern US and Canada, where conditions are far from temperate; these regions are generally described as having continental climates. The only true temperate regions are those located on the western sides of continents, dominated by successive weather systems sweeping in from the oceans further to the west. The prevailing winds off the ocean keep them cool in summer and warmer than they would otherwise be in winter.3
An increase in the inclination of the axis to, say, 26° would enlarge the (theoretical) tropical and polar zones, and compress the temperate zones. Only at the midlatitudes of 45° N and S would there be little noticeable change. The temperature range in continental interiors would probably change for the worse. Increased temperature extremes in summer and winter would require a more vigorous atmospheric and oceanic circulation to transport heat from the tropics to the poles, resulting in increased storminess, fierce winds, and generally unpredictable weather patterns. If the tilt were to decrease to about 20°, the temperate zones would expand at the expense of the tropical and polar zones. Temperate flora and fauna would be able to extend their ranges north and south of the present limits. The variations between summer and winter insolation would be reduced, and the range of temperature in continental regions would be much more equable. The temperature gradient between the tropical and polar regions would be greatly reduced and less heat would need to be transferred across the temperate zone. Weather patterns would become more stable and predictable.
With an axial tilt of 30°, the tropics are at 30° latitude and polar circles at 60° latitude, so that the tropics, temperate zone, and polar zone each cover 30° of latitude in each hemisphere. With a tilt of 45°, the tropics and polar circles are at 45° latitude, and the temperate zone disappears (though temperate conditions may still exist in certain regions). With a tilt of 60°, the tropics are at 60° latitude and the polar circles at 30° latitude, which means that latitudes between 30° and 60° are within both the tropics and the ‘polar’ zone! At higher tilts, the overlap between the two zones increases, until at 90° (and 270°) it reaches 90°, so that the whole earth lies in both the tropics and the ‘polar’ zones, resulting in seasonal variations of extreme intensity even at midlatitudes. With a tilt of 0°, on the other hand, the temperate zone would cover the entire earth, and day and night would everywhere be 12 hours long. There would be no pronounced seasons, little heat flow, and the weather system would be reduced to only the gentler circulations of atmosphere and oceans resulting from the earth’s rotation.
An article in Astronomy magazine in 1992 attempted to describe the conditions that would prevail if the earth’s axis was tilted at 90°.4 In spring and autumn all parts of the earth would still have daily cycles of daylight and darkness, but there would be extended periods of constant daylight in summer and constant darkness in winter. Twice a year every latitude would experience tropical heating as the sun passed directly overhead. At a latitude of about 34° N or S, the day-night cycle would last for a total of 7.5 months of the year, while for the other 4.5 months there would be constant day or constant night, coupled with harsh summers and winters. The lengths of these periods would vary at different latitudes.
The seasonal heating cycle prevents the formation of permanent polar ice caps. The polar regions would experience the same tropical heating and high temperatures as the equatorial regions of old Earth. However, the polar regions in winter are exceptionally cold, so seasonal polar ice caps may form. Because the polar caps aren’t permanent, the oceans – and the shorelines on the continents – are higher than those on old Earth.
If seasonal polar ice caps form, the dominant force controlling weather may shift from jet streams which circle the Earth along lines of latitude to a pole-to-pole flow. This mimics the condensation flows seen on Mars, caused by the freezing and thawing of the Red Planet’s polar caps. Thermal flows created by intense heating at one location and cooling at others may replace old Earth’s trade winds and other east-west winds.
New Earth residents probably also experience significant seasonal variations in the shoreline, depending on whether the thawing of one polar ice cap occurred at the same rate as freezing at the other pole. This change in sea level would occur on top of a change in the range of tides due to gravitational effects from the Moon and Sun. ...
Biological clocks, also called circadian rhythms, help animals and plants make the best use of their waking hours, driving urges to eat, sleep, seek shelter, or store food for the winter. ... Most living things have biological clocks that run with cycles of between 23 and 25 hours. Earth’s cycle of day and night constantly realigns these cycles to keep them in sync with the changing seasons. In contrast, during experiments in which no day-night change occurs in lighting, people resort to their natural biological clock of around 25 hours to regulate their actions, such as sleep cycles.
But life on new Earth, where protracted periods of daylight and darkness exist, would have to adapt differently. Life-forms may depend exclusively upon their biological clocks to avoid the problem of the changing day-night cycle and the periods of prolonged daylight and darkness. Or perhaps the biological clocks would take over only during the periods of continuous daylight and darkness. When day and night cycles finally returned, the day-night cycle would control activities. (Would life-forms suffer from a massive dose of jet lag during the period when the day-night cycle takes over from the internal biological clock?) Perhaps life wouldn’t have biological clocks at all. Or perhaps life-forms would have a complex set of rhythms that control activities during the periods of prolonged darkness and prolonged light and that adjust to changes in the day-night cycle. Clearly, whatever dominates the biological rhythms, social and emotional aspects of humans would evolve differently on new Earth.
Using climate computer models, Williams & Pollard5 found that, with the present earth geography, higher axial tilts produce global annual-mean temperatures higher than the present mean temperature of 14.0°C: 17.6°C at a tilt of 54°, 16.4°C at 70°, and 15.5°C at 85°. They say that at axial tilts of 54° or higher, the poles receive more insolation on average than the tropics, resulting in meridional (north-south) heat flow towards the equator, rather than away from it as on the present earth, but annual warming at high latitudes is countered by reduced insolation and colder temperatures in the tropics, and low-latitude temperatures are reduced even further by the greater reflectivity of the oceans when the sun is nearer the horizon. They note that global annual-mean temperature would be independent of axial tilt if a planet were topographically uniform, whereas if there is a mix of land and ocean, ‘the exact climatic response to different obliquities will depend on the sizes and locations of continents’.
Fig. 1. Seasonal variation of global-mean temperature for the present earth with different axial tilts
With present geography and an axial tilt of 0°, the ice line in both hemispheres extends to within 50° of the equator, or approximately 20° further than the maximum ice extension on the present earth. On an earth with the continents concentrated around the equator, the snow-ice line extends to within about 40° of the equator. At very high axial tilts, an earth with the continents concentrated around the poles was found to be the most hostile to life because over half of the continental surface area had temperatures that fell below about 10°C or climbed above 50°C around the solstices, and the planet oscillated seasonally between these high- and low-temperature extremes. In January, the temperature gradient between the equator and the pole exceeded 120°C, so that temperatures reached the boiling point of water near the pole while blizzards of snow fell in the tropics only a few thousand kilometres away!
It should be borne in mind that climate models contain many flaws and fail to do justice to the negative feedbacks that have kept the earth’s mean temperature within relatively narrow bounds (~15±8°C) for over half a billion years. A glaring deficiency is the simplistic treatment of clouds, which are the most important factor determining how much of the sun’s radiation reaches the earth’s surface. Without any clouds, the temperature on earth would be about 20ºC higher. Yet climate models treat cloud cover as a constant, and see water vapour purely as a positive feedback that amplifies warming caused by CO2, leading to a high ‘climate sensitivity’ of 3ºC (meaning that temperature would rise 3º if the atmospheric concentration of CO2 doubled). Other researchers have shown that low-level clouds provide a negative feedback; rising temperatures result in more low-level clouds, which have a cooling effect, resulting in a climate sensitivity of less than 0.5ºC.6 This suggests that rather than being susceptible to ‘tipping points’ (whether natural or man-made) resulting in ‘climate catastrophe’, the earth is a self-regulating organism, with alternating cycles of warming and cooling.
1. See Paul Dunbavin, The Atlantis Researches: The earth’s rotation in mythology and prehistory, Third Millennium, 1995, pp. 82-6.
3. John Gribbin, Future Weather, Penguin, 1982, p. 69.
4. Neil F. Comins, ‘A new slant on earth’, Astronomy, July 1992, pp. 45-9.
5. D.M. Williams & D. Pollard, ‘Extraordinary climates of earth-like planets: three-dimensional climate simulations at extreme obliquity’, International Journal of Astrobiology, vol. 2, no. 1, 2003, pp. 1-19.
6. See Climate change controversies, Climategate and the corruption of climate science, https://davidpratt.info.
Fig. 2. Global temperature since the late Proterozoic (C.R. Scotese). Cenozoic temperature is based on oxygen-isotope data, and pre-Cenozoic temperature on climate indicators such as coals, evaporites and tillites.
|Began (years BP)||
Began (years BP)
|Formation of earth||
The evidence for very warm temperatures at high latitudes and glaciation at low latitudes clearly shows that the width of climatic zones has changed radically over time. Since the width of climatic zones and the range of seasonal change are largely determined by the inclination of the spin axis, this could be attributed to significant changes in axial tilt. However, things are not as simple as that, because changing the axial inclination will not automatically lead to periods of significant global warming or cooling – but that is what the climate record shows. On a warmer earth, high latitudes could have had a predominantly temperate climate even with the present axial tilt.
In this regard, it is interesting to consider the changes in the meridional thermal gradient (ΔT), i.e. the temperature difference between equator and poles, which is partly related to equator-to-pole heat transport efficiency. Today, during a relatively warm period in an otherwise cold Cenozoic era, ΔT is about 33ºC. During the globally warm Mesozoic climate, ΔT was about 19-23ºC, and during the nearly as warm Palaeocene-Eocene Thermal Maximum (55 million years ago) it was 15ºC, whereas during the last glacial maximum (21-22,000 years ago) it was about 50ºC.2
The reigning scientific belief is that since the climatic record shows that in the past, as today, the earth was generally divided into three primary zones – a mainly warm climate at low latitudes, with cooler climates at high latitudes – there is no need to invoke major changes in axial tilt. However, a number of scientists disagree with this.
Since the warming and cooling trends shown in fig. 2 were global in character and generally lasted many millions or tens of millions of years, they can obviously not be explained simply in terms of a steady shift of the axis – even allowing for the fact that according to theosophy the geological periods are much shorter than those postulated by science on the basis of radiometric dating (see fig. 3). Nor can a steady shift of the axis explain the overall cooling (with many fluctuations) during the Cenozoic. Higher-resolution temperature proxy data are confirming the long-term global cycles of climate change, while also highlighting shorter-term oscillations and regional variations. For instance, the Pleistocene ice age consisted of a succession of glacial and interglacial periods; the number of glacial periods was initially put at four, whereas modern oxygen-isotope studies from the bottom sediments of the world’s oceans indicate that there was a succession of 52 glacials and interglacials.3
As shown in fig. 2, major glaciations occurred in the late Precambrian, Ordovician, Permo-Carboniferous, and Pleistocene. Glaciation is thought to have enveloped all or most of the planet in solid ice (‘snowball earth’) at least twice and possibly three or four times between about 750 and 580 million years ago, though some tropical ocean regions may have remained ice free.4 G.E. Williams argued that the axial tilt was above 54° for most of the Precambrian, and decreased rapidly from about 60° to 26° between 650 and 430 million years ago.5 Modelling studies suggest that a high axial tilt (up to 70°) throughout the Precambrian could help to explain warm temperatures during the Archaean and/or at least some of the Proterozoic glaciations, depending on the prevailing geography.6
There have been many times during the history of the globe when the polar regions had a warm climate.7 For example, fossil plants and animals (including the first-known amphibians) indicate that warm conditions existed in the arctic regions in the Devonian. Large Permian reptiles, which must have required a warm climate, are found along the Dvina River of Russia, just below the arctic circle. A forest of late Permian age, interpreted to have lived between 80 and 85°S, has been discovered on Mt. Achernar in the Transantarctic Mountains. Small ephemeral ice-sheets appeared on Antarctica throughout the late Eocene. In the earliest Oligocene (~33.5 million years ago) a climatic threshold was apparently crossed, allowing the rapid formation of large ice-sheets. The conventional view used to be that ice-sheet growth in the northern hemisphere began no earlier than about 15 million years ago. But there is now evidence of ice on Greenland and episodic sea-ice formation in the Arctic up to 30 million years earlier. After a warmer period from the late Eocene until the late-middle Miocene, permanent ice sheets were established on Antarctica and in the Arctic some 14 million years ago.8
The overall climate of the Mesozoic, and more specifically of the Cretaceous, was warmer than that prevailing over the globe today. Modern tropical to subtropical conditions extended to at least 45°N and possibly to 70°S, with warm- to cool-temperate climates beyond this zone. This warm global climate was also notably equable. In the Triassic some amphibians ranged all the way from 40°S to 80°N. In the Cretaceous large dinosaurs and trees existed in such high-latitude localities as Svalbard and the North Slope of Alaska. In the late Palaeocene to mid-Eocene, there were forests on Ellesmere Island (80°N) with crocodilian bones, palm trees in west-central Greenland and southern Alaska, and mangrove swamps in the London-Paris basin. During the late middle Eocene, tropical rainforest occurred at least 20° and possibly 30° poleward of the present northern limit. The Miocene floras of Grinnell Land, Greenland, and Spitzbergen all required temperate climatic conditions with plentiful moisture.9 Large Pliocene trees in fossil forests have been discovered at 82.5°N in northern Greenland and 83.5°S in the Beardmore Glacier area of Antarctica.
Large trees live in parts of the Arctic today in a much colder climate than usually prevailed in the past, and some sizable trees in Siberia live as far north as 73°N. However, controversy surrounds the question of whether the big trees, widespread vegetation, and abundant, large animals that occupied these regions in the past could have survived under polar-light conditions such as those that exist with an axial tilt similar to the present one. Some scientists argue that the earth’s axial tilt must have been as low as 5-15° to explain the occurrence of subtropical floras in high latitudes during the Cretaceous and Palaeogene (early Cenozoic).10 H.A. Allard argued that the weak climate zonation that characterized certain geological eras is difficult to harmonize with a strongly tilted axis such as now prevails; he believed that in the Cretaceous, when there was little seasonal change, the tilt was around 0°.11
Opponents of this view argue that although a smaller axial tilt would increase the winter solar insolation at high latitudes, the mean annual insolation would decrease, leading to cooler polar temperatures, whereas the evidence points to warmer polar temperatures in Mesozoic and early Cenozoic time; an alternative explanation is that life may have adapted to a polar-light regime.12 However, the climatic models on which such views are based have been challenged. Jack Wolfe suggested that at some critical value of axial inclination, the atmospheric circulation changes from one that is predominantly cellular (i.e. east-west, as it is today) to one that is predominantly meridional, which would have more than compensated for decreased annual insolation at high latitudes.
It is also conceivable that trees could have grown in polar regions if the earth had a much higher obliquity than at present. Fred Dick suggested that with an inclination of say 45°, an orbit of considerable eccentricity, and midwinter at perihelion, the Greenland summers would have been long and warm enough for the trees that used to grow there.13 This possibility illustrates how difficult it is to draw firm conclusions about the inclination of the axis on the basis of palaeoclimatic and palaeontological data.
It is stated in theosophical literature that the poles have been cold and warm in turn,14 and this is supported by the climatic record. But these climatic cycles did not just affect the polar regions. According to an ancient Commentary, the third (Lemurian) root-race was at about the midpoint of its development when: ‘The axle of the Wheel tilted. The Sun and Moon shone no longer over the heads of that portion of the Sweat Born; people knew snow, ice, and frost, and men, plants, and animals were dwarfed in their growth.’15 This may refer to the cooling period that began in the late Jurassic (see fig. 2).16
An overall gradual warming took place from the Palaeocene to the mid-Eocene, followed by gradual cooling until the major climatic deterioration at the end of the Eocene, though there were several fluctuations during this period. Since then, one major trend of northern hemisphere climates has been a decrease in the mean annual range of temperature and thus increased equability, though again there have been several fluctuations. Jack Wolfe postulates that if the major climatic trends during the Tertiary were largely the result of changes in the inclination of the axis, then from the Palaeocene to the mid-Eocene the inclination gradually decreased from around 10° to 5°. It then began to increase slightly until the end of the Eocene, when the inclination increased rapidly to 25-30°. Since then, he believes that the inclination has gradually decreased to the present average value of 23.5°. He admits that this model does not explain several fluctuations in mean annual temperature, which might result from fluctuations in the amount of solar radiation reaching the earth.17 Xu Qinqi has argued that the main cause of the alternation of glacial and nonglacial periods is the variation of the obliquity between about 10 and 25°.18 Clearly such scenarios are still very conservative by comparison with the changes in axial inclination implied in theosophical writings.
Since early Pliocene time the width of the temperate zone is said to have changed by more than 15° (1650 km) in both the northern and southern hemispheres. If we apply the rule of a 4° axial shift per precessional cycle, the theoretical temperate zone (as defined solely by the axial tilt) should have changed by 90° in each hemisphere since the beginning of the Pliocene (about 1.87 million years ago on the theosophical timescale), though this could be obscured by the complexity of the climate system. At the start of this period, the inclination of the axis would have been about 48°, and it proceeded to pass through 90°, 180°, and 270°, before reaching its current value of about 336.6° (23.4°). At the beginning of the Pleistocene (about 1,090,000 years ago on the theosophical timescale), the tilt would have been about 190°, and the earth’s north pole would have made an angle of 30° with the south ecliptic pole. A series of glacial and interglacials ensued, and the present interglacial began about 11,700 years ago, when the earth’s tilt would have been about 25°. We do not know for certain whether this is the theosophical scenario, since we have not been given any details of exactly how the axial tilt has evolved during this period. The end of the last ice age between 13,000 and 8000 years ago was accompanied by a 120-metre rise in sea level and widespread flooding. The late Pleistocene also saw large-scale volcanic activity, and the extinction of large animal species in many parts of the world. Blavatsky says that the last major cataclysm occurred about 12,000 years ago,19 but she does not explicitly link this with a poleshift. The submergence of Poseidonis, the last remaining Atlantean island in the Atlantic, is said to have occurred in 9565 BCE.20
1. Geological timescale, https://davidpratt.info.
2. Thomas M. Cronin, Paleoclimates: Understanding climate change past and present, Columbia University Press, 2010, p. 77; Palaeomagnetism, plate motion and polar wander (Palaeoclimate), https://davidpratt.info.
3. K.M. Cohen & P.L. Gibbard, ‘Global chronostratigraphical correlation table for the last 2.7 million years, v. 2010’, www.stratigraphy.org.
4. Cronin, Paleoclimates, p. 60.
5. G.E. Williams, ‘History of the earth’s obliquity’, Earth-Science Reviews, vol. 34, 1993, pp. 1-45.
6. G.S. Jenkins, ‘Global climate model high-obliquity solutions to the ancient climate puzzles of the faint-young-sun paradox and low-latitude Proterozoic glaciation’, Journal of Geophysical Research, vol. 105, no. D6, 2000, pp. 7357-70; G.S. Jenkins, ‘High obliquity as an alternative hypothesis to early and late Proterozoic extreme climate conditions’, in: G.S. Jenkins, M.A.S. McMenamin, C.P. McKey & L. Sohl (eds.), The Extreme Proterozoic: Geology, geochemistry, and climate, American Geophysical Union, Geophysical Monograph 146, 2004, pp. 183-92; Y. Donnadieu, G. Ramstein, F. Fluteau, J. Besse & J. Meert, ‘Is high obliquity a plausible cause for Neoproterozoic glaciations?’, Geophysical Research Letters, vol. 29, no. 23, 2002, doi:10.1029/2002GL015902.
7. A.A. Meyerhoff, A.J., Boucot, D. Meyerhoff Hull & J.M. Dickins, Phanerozoic Faunal & Floral Realms of the Earth, Geological Society of America, Memoir 189, 1996, pp. 46-9; Charles H. Hapgood, The Path of the Pole, Chilton Book Company, 1970, pp. 61-7; Jack A. Wolfe, ‘A palaeobotanical interpretation of Tertiary climates in the northern hemisphere’, American Scientist, vol. 66, 1978, pp. 694-703; Jack A. Wolfe, ‘Tertiary climates and floristic relationships at high latitudes in the northern hemisphere’, Palaeogeography, Palaeoclimatology, Palaeoecology, vol. 30, 1980, pp. 313-23; J.G. Douglas & G.E. Williams, ‘Southern polar forests: the early Cretaceous floras of Victoria and their palaeoclimatic significance’, Palaeogeography, Palaeoclimatology, Palaeoecology, vol. 39, 1982, pp. 171-85.
8. Cronin, Paleoclimates, pp. 87-8, 104-7.
9. Blavatsky says that Greenland was an ‘almost subtropical land’ in the Miocene (The Secret Doctrine, TUP, 1977 (1888), 2:12). The three plant species she cites as evidence (2:726) all grow in temperate climates today. See also scotese.com.
10. Wolfe, ‘A palaeobotanical interpretation of Tertiary climates in the northern hemisphere’; ‘Tertiary climates and floristic relationships at high latitudes in the northern hemisphere’; Douglas & Williams, ‘Southern polar forests: the early Cretaceous floras of Victoria and their palaeoclimatic significance’; Xu Qinqi, ‘Climatic variation and the obliquity’, Vertebrata PalAsiatica, vol. 18, 1980, pp. 334-43.
11. H.A. Allard, ‘Length of day in the climates of past geological eras and its possible effects upon changes in plant life’, in: A.E. Murneek & R.O. Whyte (eds.), Vernalization and photoperiodism: A symposium, Chronica Botanica, 1948, pp. 101-19.
12. E.J. Barron, ‘Climatic implications of the variable obliquity explanation of Cretaceous-Paleogene high-latitude floras’, Geology, vol. 12, 1984, pp. 595-8.
13. F.J. Dick, The Theosophical Path, February 1912, p. 86.
14. The Secret Doctrine, 2:150, 329, 356, 770fn, 771fn, 773-4, 777.
15. Ibid., 2:329. It is not clear whether the cooling resulted from an increase or decrease in axial tilt.
16. No unequivocal evidence has yet been found of Jurassic glacial deposits, but there is some evidence that climates were cool enough for sea ice to form at high latitudes (M.J. Hambrey & W.B. Harland (eds.), Earth’s Pre-Pleistocene Glacial Record, Cambridge University Press, 2011 (1981), pp. 952-3, books.google.nl).
17. Wolfe, ‘A palaeobotanical interpretation of Tertiary climates in the northern hemisphere’; ‘Tertiary climates and floristic relationships at high latitudes in the northern hemisphere’.
18. Xu Qinqi, ‘On the causes of ice ages’, Scientia Geologica Sinica, vol. 7, 1979, pp. 252-63; ‘Climatic variation and the obliquity’.
19. The Secret Doctrine, 2:8-9.
20. The Mahatma Letters to A.P. Sinnett, Theos. Univ. Press, 2nd ed., 1926, pp. 151/155.
Poleshifts: Part 5