This article weakens the sun spot theory of climate change. The observed very low sun spot activity is oft quoted as the reason for the little ice age. For us the real sigificance is that if the Arctic becomes ice free, Greenland ice could start to melt rapidly, shutting down the gulf stream and causing a freeze. This would start up the Gulf stream and melting would resume. This flick-flacking of the climate between the present state and the new state would be far more dissruptive to agriculture than a flip to a new stable state.