GGR314H1 Lecture Notes - Lecture 1: Sulfur Hexafluoride, Exponential Decay, Anaerobic Digestion
Document Summary
January 6, 2020: solar radiation largely absorbed at earth"s surface, surface emits infrared (thermal radiation) Some is absorbed by clouds and greenhouse gases in the atmosphere: everything with temperature above absolute emits electromagnetic radiation, reduction in outgoing radiation is greenhouse effect. System will emit more radiation to balance increase in incoming radiation. Natural ones: humans change albedo of plant through actions such as deforestation, greenhouse gases are, water vapor, carbon dioxide, methane, nitrous oxide. Sulfur hexafluoride: atmospheric carbon dioxide concentrations are increasing. From average of 280 ppm over last millennium to 410 ppm today. Carbon dioxide concentrations also have seasonal cycle because of plants: photosynthesis in summer, decay in winter. Influenced by greater proportion in northern than southern hemisphere: carbon dioxide emissions are absorbed by the atmosphere, oceans, and terrestrial biosphere. In drier el nino years, more emissions from biosphere because plants absorb less. Airborne fraction is ratio of observed increase in atmospheric carbon dioxide to estimated.