GC 170 1st Edition Lecture 5 Outline of Last Lecture I Greenhouse gases A Definition of greenhouse gases B The sun C Goldilocks principle a The earth is the perfect location CO2 II Electromagnetic radiation a Wavelength b Frequency c Electromagnetic Spectrum III Forms of Energy a Definition of energy b Potential c Kinetic d Thermal e Electromagnetic IV Flux a Definition of Flux Outline of Current Lecture I Ecological Footprint Assignment a Homework explanation II Carbon footprint a Why is it important b How are we all participating III The greenhouse effect a When and how is CO2 absorbed IV Radiation laws a 4 laws These notes represent a detailed interpretation of the professor s lecture GradeBuddy is best used as a supplement to your own notes not as a substitute i Explanations ii Current Lecture I Ecological Footprint assignment II a Read What it Measures and FAQ and answer questions b We produce carbon in 4 categories consumption categories i Carbon home energy use and transport ii Food footprint land needed to produce our food absorb CO2 producing food iii Housing Footprint how much space use how much energy is used to heat cool homes iv Goods and Services How much land is needed to produce the products we consume c Do the Ecological Footprint Quiz 2x d Print out the results page for both quiz attempts bring to class with at home assignment Carbon Footprint III IV a Concept of carbon sequestration i Ocean and plants take up CO2 from the atmosphere 1 Stored in plant and animal matter in the soils and ocean water therefore CO2 is removed from the atmosphere 2 16 67 hectares to absorb 1 metric ton of carbon in the atmosphere The Greenhouse Effect a Earth absorbs solar shortwaves b Earth emits longwave radiation c Longwaves absorbed by greenhouse gases d Greenhouse gases re emits energy e Lower atmosphere is heated i Explanation of how the earth gets warm because of the sun that is so far away Radiation a The Radiation Laws i With Allowing time look up graphs to show each law may be more clear ii Inverse Square Law 1 If we double the distance from the source the intensity of radiation decreases by for the same unit area 2 As the distance from the source increases the intensity decreases exponentially iii Planck Function Law V 1 The Planck function relates the intensity of radiation to the wavelength emitted by a blackbody emits at 100 wavelengths iv Wien s Law 1 A blackbody has a maximum radiation flux that is inversely related to the temperature of the blackbody a The lower the temperature of a body the longer peak wavelength lower energy flux b The higher the temperature of a body the shorter the peak wavelength higher energy flux c The higher the temperature the lower the peak wavelength v The Stefan Boltzman Law b Why does UV radiation irritate our skin but not infrared radiation i Shorter Wavelengths high frequency transmit more energy c How does Flux affect our climate i More radiation is absorbed at the equator which makes it warmer Definitions a Temperature measure of the internal heat energy of a substance i Celcius ii Fahrenheit iii Kelvin used mostly for global change b Blackbody an hypothetical object that emits and absorbs electromagnetic radiation with 100 efficiency at all wavelengths i Sun Earth treated like blackbodies