"Solar cycles
Solar cycles are cyclic changes in behaviour of the Sun. Many possible patterns have been suggested; only the 11 and 22 year cycles are clear in the observations.


2,300 year Hallstatt solar variation cycles.
11 years: Most obvious is a gradual increase and decrease of the number of sunspots over a period of about 11 years, called the Schwabe cycle and named after Heinrich Schwabe. The Babcock Model explains this as being due to a shedding of entangled magnetic fields. The Sun's surface is also the most active when there are more sunspots, although the luminosity does not change much due to an increase in bright spots ( faculae).

22 years: Hale cycle, named after George Ellery Hale. The magnetic field of the Sun reverses during each Schwabe cycle, so the magnetic poles return to the same state after two reversals.

87 years (70-100 years): Gleissberg cycle, named after Wolfgang Gleißberg, is thought to be an amplitude modulation of the 11-year Schwabe Cycle (Sonnett and Finney, 1990).Braun, et al, (2005)

210 years: Suess cycle (a.k.a. de Vries cycle). Braun, et al, (2005).

2,300 years: Hallstatt cycle
Other patterns have been detected:

In carbon-14: 105, 131, 232, 385, 504, 805, 2,241 years (Damon and Sonnett, 1991).

During the Upper Permian 240 million years ago, mineral layers created in the Castile Formation show cycles of 2,500 years.
The sensitivity of climate to cyclical variations in solar forcing will be higher for longer cycles due to the thermal inertia of the ocean, which acts to damp high frequencies. Scafetta and West (2005) found that the climate was 1.5 times as sensitive to 22 year cyclical forcing relative to 11 year cyclical forcing, and that the thermal inertial induced a lag of approximately 2.2 years in cyclic climate response in the temperature data."


Predictions based on patterns
A simple model based on emulating harmonics by multiplying the basic 11-year cycle by powers of 2 produced results similar to Holocene behaviour. Extrapolation suggests a gradual cooling during the next few centuries with intermittent minor warmups and a return to near Little Ice Age conditions within the next 500 years. This cool period then may be followed approximately 1,500 years from now by a return to altithermal conditions similar to the previous Holocene Maximum.
There is weak evidence for a quasi-periodic variation in the sunspot cycle amplitudes with a period of about 90 years. These characteristics indicate that the next solar cycle should have a maximum smoothed sunspot number of about 145±30 in 2010 while the following cycle should have a maximum of about 70±30 in 2023.
Because carbon-14 cycles are quasi periodic, Damon and Sonett (1989) predict future climate:
Cycle length Cycle name Last positive
carbon-14 anomaly Next "warming"
232 --?-- AD 1922 (cool) AD 2038
208 Suess AD 1898 (cool) AD 2002
88 Gleisberg AD 1986 (cool) AD 2030