ENVIRSC 1A03 Chapter Notes - Chapter 20: Global Temperature Record, Clastic Rock, Northern Hemisphere
25 Sep 2016
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Document Summary
Unit 20 climate variability and feedbacks: unit 1 scales and feedbacks. Climate change is the norm and the processes involved are interconnected and the timescales involved may vary. The timescales can be; annual, decadal, centennial (that is occurring over centuries), millennial (occurring over thousands of years or even over millions of years). For example, earth has been going through a general cooling trend for the past 3 million years. Proxy data provides an indirect record of past climate, information is preserved over a long period of time. For example, past temperatures are recorded by tree rings, corals and fossils. Scientists determine oxygen ratios for ice cores obtained from the greenland and arctic sheets and from alpine glaciers at lower latitudes. Ice cores are used to obtain temperature data from isotope ratios and provide past information on the chemistry of the atmosphere and on the incidents of past volcanic eruptions.
