Suddenly we are no longer so sure it was human activity anymore (suddenly for anyone who hasn't read John Gribbin's book at least): http://www.cnn.com/2005/TECH/science/04/08/earth.past.future/index.html Peter -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist