No Sunspots for Decades?

Two solar scientists—Matthew Penn and William Livingston, with the National Solar Observatory (NSO) in Tucson, Arizona—are predicting that by 2016 there may be no remaining sunspots, and the sun may stay spotless for several decades. They’re basing their prediction on the measurement of the magnetic field strength of 1,500 sunspots since 1990. What they have found is that the average strength of the magnetic fields is declining. When the magnetic field strength falls below a particular value, sunspots are unable to form.