Geography 2152F/G Lecture Notes - Lecture 6: Plate Tectonics, Facula, Milankovitch Cycles
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Between ages, temperature was slightly warmer than it is today. The issue today is not the temperature, but the rate of temperature change. 18,000 years ago, all of canada covered in ice. Rapid temperature rise in the last 100 years. Corresponds to the industrial revolution, increase in greenhouse gas. Causes of climate change: variations in solar radiation, sun emits more energy during periods of high sunspot activity a. i. Sunspot cool region of high magnetism on the sun a. ii. Occur in cycles, reach maximum level every 11 years a. iii. Sunspots are surrounded by faculae (bright area, emits high amount of energy: solar output changes 0. 1-0. 2, changes in composition of the atmosphere, addition of greenhouse gases increases temperature, carbon dioxide has a long residence time (100 years) If we reduce emissions today, effects will not be felt for decades c: warming is inevitable for the rest of our lives, determining past climates e. i.