AOSC401 Global Environment
Fridays 10-12:45    Room: CSS 2416    Credits: 3   Instructor: Prof. Ning Zeng   Course web:

Week 1
Organizational meeting
Introduction to greenhouse effect

Week 2
AMS seminar at the Dirksen Senate Building, Capitol Hill
 "Multiple Lines of Evidence:  The Scientific Case for Global Warming and its Causation"

Week 3
What makes Mars too cold, Venus too warm, and Earth just right?
    One-layer radiative balance atmospheric model
     Three determinators of surface temperature:
         1. Distance to the Sun, and other orbital factors
         2. Planetary albedo
         3. The greenhouse effect,  H2O, CO2, CH4, etc...
The natural carbon cycle
The disturbed carbon cycle   (need to know some basic number there: anthro emission vs. natural pools, fluxes...)
First reading assignment:  IPCC AR4 chapters;  Handouts: IPCC Tech summary, Contents

Key concepts, numbers:  
  atmo co2 concentration:   380 present, 280ppmv past
  1PgC=1GtC, about 2ppmv   (concentration vs. total amount)
  Residence time = pool/flux
  Fossil carbon emission:  8GtC/y, about half left in the atmo, rest taken up by ocean and land
  How do we burn so much:   Each person drives 10,000mile/y, that is a 1 tone of carbon released!
  How much is 1GtC:   1 cubic kilometer of coal
Reading:  Ch3 of Kump, the Earth System

Week 4
The history of global warming
Satellite Infrared movie: showing clouds, diurnal cycle, midlatitude vs tropical storms etc.
Global precipitation pattern:
   Midlatitude storm tracks
   Subtropical dry zones

Week 5
Climate change:  what's happening now (warming by .7 degree in 20th century, glacial retreating, etc.)

Week 6
Reading assignment presentations.  IPCC chapters by Dave, Laura, Juli, Robby

Week 7
Presentation continues: Graham, Tricia
Climate feedbacks:
      IR (Stefan-Boltzman law)    about 1 deg warming at 2xCO2
    Water vapor (positive, fast)  1-2 deg
    Snow-albedo (positive, but slow)
    Carbon cycle feedback (probably positive as the current sinks saturate)

Week 8

Spring Break

Week 9
Fossil fuel energy use as a major source of CO2 emission
   90% of our energy use from fossil fuel:  oil, gas, coal
   Coal: derived from ancient vegetation. Four  types:  peat, brown coal (soft), bituminous (hard), anthracite
    Oil, gas:   derived from oceanic biota such as plankton,
    Fossil fuels are derived from ancient life (plants/plankton) transformed in sediments by physical and chemical processes due to heat and pressure
They are all hydrocarbons (saturated C2nH2n+2 and unsaturated C2nH2n) such as CH4 (methane), C3H8 (propane), plus some S, N, etc. (especially coal). Between 50-95% of the mass is carbon
Gas is rapidly running out, coal is expected to surpass oil soon due to its cheapness and abundance, but coal is least efficient (more carbon emission per unit energy produced) and dirtiest.
   Current world fossil fuel consumption is about 14 TW (terra watts), emitting close to 8 GtC/y, with US 25%, China 23%, Russia, ...; China is expected to surpass US in the near future, although its per capita consumption is less than 1/5 of US.
   Question: I said in class that each of us typically consumes 1tC/y by driving 10,000miles/y; recompute this using a typical carbon content of gasoline (you should be able to estimate it now).