During recent years,the occurrence of abrupt climatic changes during the earth's history has aroused much interest.Recent investigations have shown the occurrence of catastrophes in the behavior of radically simplified deterministic climate models,and the existence of Abrupt Climatic change in the past times.There might be various kinds of abrupt changes existed in the climatic system,but two types of abrupt climatic change were usefull.Type 1 was a simple state change,i.e.,a repid and statistically significant change in some observed measure of the climate system s regime that occured in the absence of any fundamental change in the system's structure,or any long-term change in its external boundary conditions,such as the first killing frost,and the onset of the monsoon.Type 2 is a rapid change of climate that reflects a long-term change in the system's bounmdary conditions.Such events must occur occasionally,for example,as slow tectonically driven changes in geography permit new nodes of atmospheric or oceanic circulation.