ENVS 2270 Lecture Notes - Lecture 11: Dendroclimatology, Positive Feedback, Paleoclimatology
12 Oct 2016
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Name several climate proxies: tree rings, ice cores, pollen, coral, marine sediments, lake sediments, diatoms, stalactites/stalagmites. What is dendroclimatology: using trees and specifically tree rings as a climate proxy, to give us information about climate. What kind of information can be obtained from ice cores: air composition > co2 levels, dust particles, layers - gives information about dating, precipitation levels, stable isotope information. What is palynology: study of pollen - often used in the context of climate change. *what makes climate proxies useful is that we can put a date on the information about climate* We get dates from 2 sources > radioactive isotopes, and biological organisms where age can be estimated from growth rate and patterns of organism. Intensity of radiation from the sun varies with cyclical changes in: the tilt of earth"s axis (obliquity) Determines the seasons: the shape of the earth"s orbit (eccentricity, the way the axis wobbles (precession)
