Mr. Brooks has studied deeply geology, anthropology, and meteorology, and he has considerable mathematical ability. By applying the latter to the results of his studies he has developed a theory for the cause of climatic changes based on changes of land and sea area, and on changes of elevation of land surfaces, and naturally he has made this theory the basis of his work. That there will be some who are not able to agree with him as to the sufficiency of the causes he invokes, or who may even question whether he also has not taken for granted what others dispute, goes without saying; but all will agree that he has presented a difficult subject in a clear and concise way, and that meteorologists (and may I add geologists?) owe to him a deep debt of gratitude. G. C. SIMPSON. CONTENTS PAGE PREFACE 5 INTRODUCTION 11 I. FACTORS OF CLIMATE AND THE CAUSES OF CLIMATIC FLUCTUATIONS 15 II. THE CLIMATIC RECORD AS A WHOLE 32 III. CONDITIONS BEFORE THE QUATERNARY ICE AGE 42 IV. THE GREAT ICE AGE 47 V. THE GLACIAL HISTORY OF NORTHERN AND CENTRAL EUROPE 55 VI. THE MEDITERRANEAN REGIONS DURING THE GLACIAL PERIOD 68 VII. ASIA DURING THE GLACIAL PERIOD 76 VIII. THE GLACIAL HISTORY OF NORTH AMERICA 86 IX. CENTRAL AND SOUTH AMERICA 97 X. AFRICA 103 XI. AUSTRALIA AND NEW ZEALAND 109 XII. THE GLACIATION OF ANTARCTICA 114 XIII. THE CLOSE OF THE ICE AGE—THE CONTINENTAL PHASE 118 XIV. THE POST-GLACIAL OPTIMUM OF CLIMATE 127 XV. THE FOREST PERIOD OF WESTERN EUROPE 136 XVI. THE “CLASSICAL” RAINFALL MAXIMUM, 1800 B.C. TO A.D. 500 140 XVII. THE CLIMATIC FLUCTUATIONS SINCE A.D. 500 149 XVIII. CLIMATIC FLUCTUATIONS AND THE EVOLUTION OF MAN 159 XIX. CLIMATE AND HISTORY 162 APPENDIX—THE FACTORS OF TEMPERATURE 166 INDEX 169 INTRODUCTION