[spokeshave]

Nice graph....but try this one for size....

And hears the kicker" Whenever SOLAR RADIATION has DECREASED and VOLCANIC ACTIVITY INCREASES, global temperatures SUDDENLY PLUMMET, OFTEN WITHIN WEEKS OR MONTHS

So forget volcanoes.....and focus on the decline of the Sun's magnetic field....resulting in less sunspots...

[HiTech RedNeck]

It is an interesting theory, though one we can only attempt to evaluate over the history of volcanic activity. Is there some way to look at this way back during ice ages?