This is a topic with a lot of question marks in the scientific community. To my knowledge, it is getting weaker, but we don't know any timescales, where we would be in the shift, what it might do to climate or ecosystems, etc. Certainly no consensus has emerged despite a lot of study, and I've not done too much research into the topic but I know that through paleomagentism we know when they have reversed in the past, and there have been dozens upon dozens of reversals, and I'm sure there is a great deal of correlating between that and paleoenvironments to look for what it might do to climates and biology and other things, but for prediction I would not rely on it. Certainly would be interesting to get more details, and it is always interesting for scientists to learn "new physics." Perhaps if I can find a good paleomagnetist I will e-mail him
A lot of reversals here to explain the changes we're having today. I don't think we have anything past 160 mya because of plate tectonics (we don't have seafloor past about 200 million years old)-- Chris
