  The sunspot number observations over the past three centuries measure solar
activity. These numbers repeat the solar cycle of about eleven years. The solar
dynamo converts convective motion and internal differential rotation into
electric-magnetic energy that sustains the solar magnetic field. This field
concentrates on sunspots on the surface of the Sun. The mainstream dynamo
models predict that the sunspot cycle is stochastic. The official Solar Cycle
Prediction Panel forecasts only the ongoing sunspot cycle because any forecast
beyond one cycle is considered impossible. We apply the Discrete Chi-square
Method (DCM) to the monthly and yearly sunspot data. DCM can detect many
periodic signals superimposed on an arbitrary trend. The sunspot data fulfil
four criteria. (1) DCM consistently detects the same periods in the yearly and
monthly data. (2) We divide each sunspot data sample into the longer predictive
data sample and the shorter predicted data sample. DCM models for the
predictive data can predict the predicted data. (3) DCM models can predict the
past prolonged Dalton and Maunder activity minima. Our predictions are longer
and more accurate than the official Solar Cycle Prediction Panel forecast. We
predict that during the next half a century the Sun will no longer help us to
cope with climate change. (4) DCM detects planetary signal candidates. The
solar cycle is deterministic, not stochastic, if the Earth and Jupiter cause
the strongest detected, very clear 10, 11 and 11.86 year signals shown in our
Figure 5. If the Earth's signal dominates over Jupiter's signal, the planetary
gravitational tidal forcing does not cause the sunspot cycle. The Earth's and
Jupiter's dipole magnetic fields may interact with the solar magnetic field.
The geomagnetic field may even be the main cause of the sunspot cycle, if our
results in Table 14 are correct.
