GEOG 200 Lecture 1: GEOG 200 Notes.docx
13 Oct 2014
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Scientists think this is not a major factor in 20th century climate change: milankovitch cycles: variation in the earths orbit around the sun affects amount of radiation received by the atmosphere and therefore temperature, changing tilt in the planet gets us a different amount of radiation, changes length of seasons: up to 20% difference in radiation, with feedbacks, explains climatic variability of last million years. Earth would be 30d egress colder without the greenhouse effect: this isn"t the problem, it"s the magnification of the greenhouse effect which is becoming the problem, known greenhouse gasses, water vapour, carbon dioxide, methane, nitrous oxide. Complexity in attribution: many influences on the climate, operating on different temporal scales, parts of the system feedback on other parts of the system make it difficult to create a direct cause and effect, time lags between cause and effect, the concentration and emissions in the atmosphere now will have an effect on future years assess.
