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
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Abstract
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.
Conclusion
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. …
