Does that mean that no uncertainty exists? Of course not. More research—including old fashioned geological data collection—is necessary to get a clearer picture. For now, Putnam says that in terms of extrapolating forward about future impacts, the data makes the most sense in terms of regional patterns on a decade-long scale. You can say, for example, that over a period of around ten years, the American west is going to be drier—but of course in any given year within that period, it can still be unusually wet, especially in smaller locations.