The Trend of West Environment Changes in Tang and Song Dynasties

West environment,from Tang dynasty to Song dynasty,in this article mainly is divided two big historical periods is Tang to the Northern Song Dynasty first year,elaborates natural environment vicissitude,the Northern Song Dynasty intermediate stage to the Southern Song Dynasty,as well as environment and so on politics,economy,culture which brings by it vicissitude,and thought mainly is because from Tang to song,this historical period climate coldly is the result of by the warm extension.This tremendous change,at that time as well as the present has had the profound influence to the west,from this also obtains some enlightenment.