Have you seen "Solar Force" on National Geographic's, Naked Science?

It airs again on November 6th & the 8th. It says that scientist know that the sun has been the major climate driver in the past, but scientist have not been able to figure out why a .15%variation of intensity has such a profound effect on the climate. They show a huge 1365 watt lamp shining on one square meter to simulate the suns effect on the surface of the Earth and then turn on a little flashlight to simulate the variation of the sun's intensity. They say that the change isn't enough. Then they show two solar physicists and one atmospheric physicist that each have a theory about the possible mechanisms that the sun could change our climate in a more powerful way.