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Some climatologists and climate modelers argue for a '1500-year climate cycle' in the North Atlantic region. A Pervasive Millennial-Scale Cycle in North Atlantic Holocene and Glacial Climates, Bond, G., , , Science, In their view, many if not most of the Dansgaard-Oeschger events of the last ice age, conform to a 1500-year pattern, as do some climate events of later eras, like the Little Ice Age, the 8.2 kiloyear event, and the start of the Younger Dryas.
The hypothesis holds that the 1500-year cycle displays nonlinear behavior and stochastic resonance; not every instance of the pattern is a significant climate event, though some rise to major prominence in environmental history.^[1] Causes and determining factors of the cycle are under study; researchers have focused attention on patterns of tides, variations in solar output, and "reorganizations of atmospheric circulation."^[2]
Looking backward from the present, the following events appear to conform to a general 1500-year pattern. (Evidence is more problematic, and certainty weaker, farther back in time.)

★ 700 years before the present (BP), or 1300 AD — the start of the Little Ice Age (by some calculations); the Great Famine of 1315–1317

★ 2200 BP, or 200 BCE — ?

★ 3700 BP, or 1700 BCE — ?

★ 5200 BP, or 3200 BCE — the Piora Oscillation

★ 6700 BP, or 4700 BCE — ?

★ 8200 BP, or 6200 BCE — the 8.2 kiloyear event

★ 9700 BP, or 7700 BCE — ?

★ 11,200 BP, or 9200 BCE — ?

★ 12,700 BP, or 10,700 BCE — the start of the Younger Dryas

★ 14,200 BP, or 12,200 BCE — the Older Dryas.
Global warming skeptics have used the 1500-year climate cycle to argue against anthropogenic global warming;^[3] but the hypothesis itself exists independent of political considerations. One leading researcher in this area has been Dr. Gerard C. Bond of the Lamont-Doherty Earth Observatory at Columbia University.^[4]

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References

References

1. Cox, John D. ''Climate Crash: Abrupt Climate Change and What It Means for Our Future.'' Washington DC, Joseph Henry Press, 2005; pp. 150-5.
2. Cox, pp. 154-5.
3. Avery, Dennis T., and Siegfried Fred Singer. ''Unstoppable Global Warming: Every 1500 Years.'' New York, Rowman & Littlefield, 2006.
4. National Research Council (U.S.) ''Radiative Forcing of Climate Change: Expanding the Concept and Addressing Uncertainties.'' Washington DC, National Academies Press, 2005; p. 192.