GEG 1301 Lecture Notes - Lecture 8: Positive Feedback, Tibetan Plateau, Drake Passage

• School: University of Ottawa
• Department: Geography
• Course: GEG 1301
• Professor: Prof Lekowski

Document Summary

Past climate change: methods to document change, degree of change, causes of change. Sun"s energy output- 99. 999 % comes from our sun. Amount of energy reaching earth due to variations in earth-sun geometry. Internal changes within the earth"s systems-internal things that happen like volcanic eruptions. Variations in sun"s energy output: sunspots vary in an 11-year cycle-not a constant cycle. Trends in total solar irradiance (tsi) depend on the methods used to derive a composite record from several satellites. Each satellite is operational for only a few years so the records have to be stitched together. Earth"s climate (mean temperature) relatively little in the past three decades. The total solar irradiance isn"t showing a larger/increase. There is a chance that the sun is involved with the changes but it is not definite and not likely. 5% variation in the amount of energy received from the sun.