AOSC401
Global Environment
Fridays
10-12:45 Room: CSS 2416
Credits: 3 Instructor: Prof. Ning Zeng Course
web: http://www.atmos.umd.edu/~zeng/AOSC401/
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"
http://www.ametsoc.org/atmospolicy/environmentalsssarchives.html
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:
ITCZ
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).