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Unformatted text preview: Britani Keszler 2-6-08 Assignment #1, Topic 2 In order to develop a further understanding of how climate change works, scientists have developed methods of determining past climates through various experiments. One experiment used is gathering sediment from the bottom of oceans and lakes and determining the surface water temperature based upon the remains of calcium carbonate shells or organisms. Others are studying geological aspects of the earth such as fossils, ancient coal beds and sand dunes to see a difference in water levels and another is determining past temperature trends by observing the oxygen-isotope ratio in ancient cores. By using these experiments scientists have discovered important past events in the earth’s climate such as the first ice age which began roughly around 700 million years ago and the most recent one occurring 25 million years ago. Another crucial event is the Younger-Dryas about 12,700 years ago in which the northeastern North American and northern Europe temperatures dropped and they relapsed into...
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This note was uploaded on 04/03/2008 for the course WEATHER AN 101 taught by Professor Weidman during the Spring '08 term at University of Arizona- Tucson.
- Spring '08