ERSC 1F90 Lecture Notes - Lecture 4: Facula, Volcanism, Little Ice Age
9 Apr 2015
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Document Summary
Greenhouse gases: absorb longwave radiation and emit some of it back to the. Greenhouse gases: water vapor, co2, methane, nitrous oxide, chlorofluorocarbons. Atmospheric lifetime: average time a molecule of a greenhouse gas will remain in the atmosphere. Global warming potential (gwp): measure of how much given greenhouse gas is estimated to contribute to global warming; relative scale which compares the gas in question to that of the same mass of carbon dioxide (gwp of 1) Overall, there"s a balance between incoming energy and energy emitted to space. Changes in any factor cause an imbalance in radiative balance and a change in climate. Radiative forcing: any change in the average net radiation (incoming minus outgoing) reaching the top of the earth"s atmosphere. Positive radiative forcing (outgoing radiation is less than incoming) causes a net increase in global temperature. Negative radiative forcing (outgoing radiation is more than incoming) causes a net decrease in global temperature.
