Occasionally the weather around us 

 obtruded itself into studies of the weath- 

 er of the past. This excerpt from a let- 

 ter to my wife is typical : 



"By Sunday noon we had channeled 

 out five big blocks [of rock containing 

 fossil fish] and right after noon I started 

 to plaster them. Just then, a big cloud 

 passed overhead, and a howling wind 

 tossed our camp bed over 50 feet high 

 in the air. It fell apart, of course, and 

 the heavy canvas dropped, but the bed 

 rolls kept on traveling, with Kenny and 

 me running after, my arms covered 

 with rapidly-setting plaster. Both 

 pillowcases blew off their pillows 

 and we located them a quarter-mile 

 apart. One air mattress landed on a 

 sharp rock and was punctured slightly. 

 The other cartwheeled half a mile be- 

 fore it stopped. After we prospected in- 

 numerable gullies for our bedding, we 

 returned and finished plastering. The 

 ground beneath the collapsed air mat- 

 tress that night was harder than I had 

 supposed." 



Desert weather is violent, as the old 

 monsoonal weather probably was not. 



Once the ancient weather pattern for 

 that one district was determined, the 

 second and more important step in the 

 research could begin. A coordinated 

 climatic map of North America must 

 be pieced together for this period 40 

 million years ago, then others for the 

 climates of 35 and 30 million years ago. 



Forty million years ago, earth cli- 

 mates were what geologists would con- 

 sider normal : warm, equable, with the 

 Poles only a few degrees cooler than the 

 Equator. Then the cooling began, 

 which led by stages to the final and 

 highly abnormal Ice Age of the past 

 one million years. Even during the Ice 

 Age, there were four periods when the 

 climate was as warm as or warmer than 

 it is today, so that more than half of the 

 Ice Age was actually not glacial. 



At the present time, the climate at 

 the Poles is warming again. This warm- 

 ing is taking place very fast, even when 

 compared with the span of human life, 

 and it is causing a strong warming trend 

 throughout most of the United States 

 and Europe. This is only part of the 

 story, however. As the temperature 

 rises, the entire wind system alters un- 



predictably. This changes the rainfall 

 pattern. Areas which now have ade- 

 quate rainfall may become dry, and dry 

 plains may receive enough moisture to 

 grow crops and develop forests. 



If we can learn from the past exactly 

 what the "normal" climatic patterns 

 were during times of general warmth, 

 and how these patterns shifted as cool- 

 ing progressed, then we can predict how 

 climatic patterns will shift in reverse 

 order as the Poles warm up. It will 

 be like watching a movie film run back- 

 wards. 



For instance, there is reason to be- 

 lieve that when maximum warmth is 

 reached Illinois will have a climate some- 

 what like that of northwest Texas today. 

 Only a better knowledge of the ancient 

 climates can tell us how soon this will 

 develop. 



In the next bulletin an article on 

 "Climates of the Past and Future" 

 will explain what we have learned about 

 the climates of our hemisphere, and out- 

 line the grave human problems that will 

 result from the changes we may expect 

 in the future. (end) 



Above: Arrows point to 

 line of volcanic ash. 



Right: Kenny's fossil 



FEBRUARY Page 7 



