believe it or not, this is actually a research area. not the astrology, exactly, but the general idea. there is a developing understanding that gravitational forces involving outside astronomical bodies are a factor in plate tectonics on earth, and planetary alignments are consequently important in understanding events like earthquakes and volcanoes - as well as their consequences, like climate change.

the best argument i can present in this space is to simply think of how tides work: gravitational forces between the earth and the moon. that should be enough to realize this isn't a crazy idea.

now, if he happens to be right, it's through luck rather than method. but, he is probably on to something.

http://www.youtube.com/watch?v=0uVI8cQ3Hpo