By Don J. Easterbrook Professor of Geology, Western Washington Univ, Bellingham, WA A fundamental axiom in geology is “The present is the key to the past,” i.e. in order to understand past geologic phenomena we need to understand present-day processes. We can also turn this adage around to say “The past is the key to the future,” i.e., in order to predict the future we need to know what has happened in the past. With that in mind, looking at temperature changes over the past millennia is very instructive about the nature of climate changes. Among the various ways of … The past is the key to the future: Temperature history of the past 10,000 years weiterlesen