Hi, In response to Linda's question regarding the influence change in the magnetic poles has on our climate, I would like to ad that it is believed by some scientists that the magnetic poles "swop" places every now and then (in geological terms) and apparently we are about 10 000 years overdue. They also found that the earths magnetic field is weakening and letting through more solar radiation which could also be contributing to Global Warming. Dave. Yes, there are those schools of thought who suggest that Global Warming is merely a "recurring phenomenon" (before the onset of yet another Ice Age), but I am not thoroughly convinced. You mentioned that CO2 was probably in greater abundance in the atmosphere during the Carboniferous Era than it is today. Where did it go? Into fossil fuels? That leads me to another question, how did all the organic material needed to produce fossil fuels get down there and where did it come from??? Regards, Pieter van der Walt South Africa