Empirical Evidence for a Celestial Origin of the Climate Oscillations and Its Implications

Nicola Scafetta. 2010. Empirical Evidence for a Celestial Origin of the Climate Oscillations and Its Implications. Journal of Atmospheric and Solar-Terrestrial Physics(2010),doi:10.1016/j.jastp.2010.04.01

Full text [here]

Selected excerpts:


We investigate whether or not the decadal and multi-decadal climateoscillations have an astronomical origin. Several global surface temperature records since 1850 and records deduced from the orbits of the planets present very similar power spectra. Eleven frequencies with period between 5 and 100 years closely correspond in the two records. Among them, large climate oscillations with peak-to-trough amplitude of about 0.1 and 0.25ºC, and periods of about 20 and 60 years, respectively, are synchronized to the orbital periods of Jupiter and Saturn. Schwabe and Hale solar cycles are also visible in the temperature records. A 9.1-year cycle is synchronized to the Moon’s orbital cycles. A phenomenological model based on these astronomical cycles can be used to well reconstruct the temperature oscillations since 1850 and to make partial forecasts for the 21st century. It is found that at least 60% of the global warming observed since 1970 has been induced by the combined effect of the above natural climate oscillations. The partial forecast indicates that climate may stabilize or cool until 2030–2040. Possible physical mechanisms are qualitatively discussed with an emphasis on the phenomenon of collective synchronization of coupled oscillators.


On secular, millenarian and larger time scales astronomical oscillations and solar changes drive climate variations. Shaviv’s theory (2003) can explain the large 145 Myr climate oscillations during the last 600 million years. Milankovic’s theory(1941) can explain the multi-millennial climate oscillations observed during the last 1000 kyr. Climate oscillations with periods of 2500, 1500, and 1000 years during the last 10,000 years (the Holocene) are correlated to equivalent solar cycles that caused the Minoan, Roman, Medieval and Modern warm periods(Bond etal.,2001; Kerr, 2001). Finally, several other authors found tha multi-secular solar oscillations caused bi-secular little ice ages (for example: the Sporer, Maunder, Dalton minima) during the last 1000 years (for example: Eddy, 1976; Eichler et al.,2009; Scafetta and West, 2007; Scafetta, 2009,2010).

Herein, we have found empirical evidences that the climate oscillations within the secular scale are very likely driven by astronomical cycles, too. Cycles with periods of 10–11, 12, 15, 20–22, 30 and 60 years are present in all major surface temperature records since 1850, and can be easily linked to the orbits of Jupiter and Saturn. The 11 and 22-year cycles are the well-known Schwabe and Hale solar cycles. Other faster cycles with periods between 5 and 10 years are in common between the temperature records and the astronomical cycles. Long-term lunar cycles induce a 9.1-year cycle in the temperature records and probably other cycles, including an 18.6-year cycle in some regions (McKinnell and Crawford, 2007). A quasi-60 year cycle has been found in numerous multi-secular climatic records, and it is even present in the traditional Chinese, Tibetan and Tamil calendars, which are arranged in major 60-year cycles. …

The existence of a 60-year natural cycle in the climate system, which is clearly proven in multiple studies and herein in Figs. 2, 6, 10 and 12, indicates that the AGWT promoted by the IPCC (2007), which claims that 100% of the global warming observed since 1970 is anthropogenic,is erroneous. In fact, since 1970 a global warming of about 0.5ºC has been observed. However, from 1970 to 2000 the 60-year natural cycle was in the warming phase and has contributed no less than 0.3ºC of the observed 0.5ºC warming, as Fig. 10B shows. Thus, at least 60% of the observed warming since 1970 has been naturally induced. This leaves less than 40% of the observed warming to human emissions. Consequently, the current climate models, by failing to simulate the observed quasi-60 year temperature cycle, have significantly over estimated the climate sensitivity to anthropogenic GHG emissions by likely a factor of three. …

19 Feb 2010, 11:21am
General Science Pre-Holocene Climates
by admin
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Variations in the Earth’s Orbit: Pacemaker of the Ice Ages

J. D. Hays, John Imbrie, N. J. Shackleton. 1976. Variations in the Earth’s Orbit: Pacemaker of the Ice Ages. Science, New Series, Vol. 194, No. 4270, (Dec. 10, 1976), pp. 1121-1132.

Note: this classic, seminal paper changed the science of paleoclimatology. It is one of the most important papers ever written in any scientific discipline.

Full text [here]

Selected excerpts:


For more than a century the cause of fluctuations in the Pleistocene ice sheets has remained an intriguing and unsolved scientific mystery. Interest in this problem has generated a number of possible explanations (1, 2). One group of theories invokes factors external to the climate system, including variations in the output of the sun, or the amount of solar energy reaching the earth caused by changing concentrations of interstellar dust (3); the seasonal and latitudinal distribution of incoming radiation caused by changes in the earth’s orbital geometry (4); the volcanic dust content of the atmosphere (5); and the earth’s magnetic field (6). Other theories are based on internal elements of the system believed to have response times sufficiently long to yield fluctuations in the range 104 to 106 years. Such features include the growth and decay of ice sheets (7), the surging of the Antarctic ice sheet (8); the ice cover of the Arctic Ocean (9); the distribution of carbon dioxide between atmosphere and ocean (10); and the deep circulation of the ocean (11). Additionally, it has been argued that as an almost intransitive system, climate could alternate between different states on an appropriate time scale without the intervention of any external stimulus or internal time constant (12).

Among these ideas, only the orbital hypothesis has been formulated so as to predict the frequencies of major Pleistocene glacial fluctuations. Thus it is the only explanation that can be tested geologically by determining what these frequencies are. Our main purpose here is to make such a test. Previous work has provided strong suggestive evidence that orbital changes induced climatic change (13-20). However, two primary obstacles have led to continuing controversy. The first is the uncertainty in identifying which aspects of the radiation budget are critical to climatic change. Depending on the latitude and season considered most significant, grossly different climatic records can be predicted from the same astronomical data. Milankovitch (4) followed Koppen and Wegener’s (21) view that the distribution of summer insolation (solar radiation received at the top of the atmosphere) at 65N should be critical to the growth and decay of ice sheets. Hence the curve of summer insolation at this latitude has been taken by many as a prediction of the world climate curve. Kukla (19) has pointed out weaknesses in Koppen and Wegener’s proposal and has suggested that the critical time may be September and October in both hemispheres. However, several other curves have been supported by plausible arguments. As a result, dates estimated for the last interglacial on the basis of these curves have ranged from 80,000 to 180,000 years ago (22).

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28 Apr 2008, 7:51pm
Pre-Holocene Climates
by admin
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An Urgent Signal for the Coming Ice Age

Harris, Peter John Faraday. 2008. An Urgent Signal for the Coming Ice Age

Full text [here]

Selected excerpts:

When paleoclimatologists met in 1972 to discuss how and when the present warm climate would end , termination of this warm climate we call the Holocene seemed imminent and it was expected that rapid cooling would lead to the coming ice age. These ideas were based on the 1M year analogue for climate transitions first proposed by Milankovitch over 60 years ago, which has been demonstrated to show the correlation of glacial and interglacial climate with solar insolation as it is modulated by our changing distance from the sun. These data sets may be used to serve as a signal for the coming ice age. Orbital geometry was approaching similar conditions to those of the previous transitions to ice.

But soon it was observed that global temperature was increasing and at about this time Global Climate Modeling (GCM) received more attention and the Milankovitch analogue was forgotten. There has been no further discussion about the coming ice age. …

Then using a modeled Holocene they projected climate using a range of CO2 forcing, and they reported that there was no transition to ice for at least 30KY into the future.
The algorithm for this process is not disclosed but the authors rightly list the limitations of the model in which CO2 is considered as an external forcing ie the carbon cycle is not simulated by the model. Clouds and the hydrological cycle are simplified and so is the heat transport to middle and deep ocean. In addition, regional changes such as the North Atlantic and over Europe are not simulated “and might depart from the global trend.”

It is unfortunate that these limitations appear to have been ignored and the AGW [anthropogenic global warming] hypothesis was born and has occupied science and the media ever since. The Milankovich analogue has been forgotten.
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