I showed in FAQ 3 the plotting of the "q" function for a long time (1400-2050). An interesting fact to remark is the size of the curve during the XVII th century, which shows large peaks involving a great amount of energy exchanged. Perhaps the three or four peaks of the beginning of the century have pushed the oscillator out of resonnance and gave the Maunder's minimum. A similar situation was encountered in 1765-1800 (three strong peaks) whith a phase advance, which coule have given the little cold period of years 1800-1825 : a minimum similar to the Maunder's one, but less strong.
There are evident similarities beetween the 1600-1650, 1765-1800 and 1975-2000 periods. One could infer that we could have in the future :