[blam]

"An example of this could be Atlantic Coast hurricanes:according to a WSJ article that I read some years back,the hurricanes that hit the Atlantic shores run on a fairly predictable 20 year cycle.

I read a science article about hurricanes that show a longer cycle. For example, 1,100 years ago the incident of category five hurricanes were much greater than today, etc.

[sawsalimb]

if I recall correctly,the article that I read claimed that the hurricanes in the Atlantic were driven by rainfall in one of the African deserts(the Sahel,maybe?-can't remember for certain),and that particular rainfall pattern had historically gone through a 20 year cycle of ups and downs. A 1000 year cycle wouldn't surprise me either,and in fact,I'd be more surprised to find out that one didn't exist,than to find out that one did.