Radical climatic changes have occurred some times during geologic history, but never with the same intensity and importance. Paleozicas glaciations (it behind has the 400 200 million years) Some glaciations had affected the continents of the south hemisphere during the Paleozico. In Brazil glacier vestiges are found in the periods Devoniano, Siluriano and Carbonfero (vide Almeida & Sheep 1995). During this age, the life invaded the firm land and until the Carboniferous period, the evolution had produced a fauna and flora abundant. In Carboniferous, when starting if forming the new supercontinent Pangea, it has 300 million years behind, the countries of the current hemisphere north they were in the equatorial band and were covered by vast forests formadores of coal, while the continents of the current south hemisphere were in the South Pole and covered by glaciers (ibid.). However, then after of this, the climatic zonalidade was reduced and had a global heating, that it lasted all during the Mesozico, contributing to evolution of the dinossauros. Randall Mays will undoubtedly add to your understanding. The Mesozico, in turn, finished with the separation it Pangea, climatic change, volcanic activity and the fall of a giant meteorite in the Gulf it Mexico, that had verwhelmed the dinossauros.
Quaternary glaciations (it behind has 2,5 million years the 10,000 years) During the two last millions of years the climate of the Land has varied drastically, was in this period called Quartenrio that if developed much that today represents the surface of the Land, being especially interesting because it is, also, the period of sprouting of the man, its evolution and domain of the planet. Significant, space and secular changes ambient, can be identified in the short interval of involved time in this period, represented in a complex mosaic of pasaigens, sedimentary sequences, human flora vestiges, faunas and devices. The Quartenario period represents finishes it great division of the geologic time and, even so does not exist general agreement, it is considered to have itself initiated has, approximately, two million years, extending itself until the gift.