EAR 105 Lecture 18: Climate of the Past and Future
30 Nov 2016
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Document Summary
Changes in earth"s climate are tied to variations in co2. Carbon dioxide concentrations have been significantly higher in the past. Climate change is as much about the rates it is about the absolute amount of change. The pleistocene epoch is typically defined as the time period that began about 1. 8 million years ago and lasted until about 11,700 years ago. The most recent ice age occurred then, as glaciers covered huge parts of the planet earth. Chemical techniques allow us to determine the temperatures in the past. Fossil plant material provides direct evidence of climate changes. Ice cored from greenland and antarctica retain bubbles of past atmospheres. Gas from bubbles in ice cores can be extracted and analyzed. The holocene epoch began 12,000 to 11,500 years ago at the close of the paleolithic ice age and continues through today. As earth entered a warming trend, the glaciers of the late paleolithic retreated.
