Quick Summary of Previous Lectures on Material Flows:

• Flow of any material (Carbon, Nitrogen, Oxygen, etc) is regulated by exchange processes between land, water and air. The exchange rates are all in equilibrium.

• Exponential use of resources causes non-equilibrium growth which seriously alters the cycle. This causes a (temporary) excess of some material in either the land, water or air. Examples:
  • Excess Carbon in the atmosphere (CO_2)
  • Excess Nitrogen in the Ocean (fertilizer mining of atmosphere)

• The Hydrological Cycle is an excellent example of equilbrium cycle with many feedback channels:
  • urbanization closes most of these feedback channels and creates a large surface runoff excess
  • Damming increases surface area and hence evaporation

Fossil Fuel Production and Consumption

Energy Consumption in the US

• This figure shows the different energy sources which have been tapped by the US from the period 1850-1990. It is full of information; study it closely

• An equally interesting tail is also provided by reading more on The Historical Price of Gas

Growth of energy use is dependent on the following factors:

• Average energy used per person has increased by a factor of 3 since 1850

• Population has increased by a factor of 11
• In recent years, East to West Migration of US Population --> this bears on the issue of energy deregulation.
• Monthly Population Data US --> growth rate is 1.1% per year

Referring to the figure referenced above, the breakdown of current energy usage by source is the following:

• Oil 42.1
• Gas 23.8
• Coal 23.3
• Nuclear 7.0 %
• Hydro 3.5
• Other 0.3

Some Pie Charts: US vs Mexico

Energy From Fossil Fuels:

• 200 - 500 million years ago stuff dies in ocean, covered with sand, crushed by sediment deposit, temperature and pressure rise, organic residue converted to oil and gas

• Where to find oil ----> Under old sedimentary rock! Pennsylvania Ohio Indiana San Fernando Valley Texas

• 1950: US production was 50% of the world's --> we therefore dominated the market and could set the price of oil

• Then: Venezuala, Mexico, Saudia Arabia, Iraq, Kuwait and Bahrain all discover rich oil fields underneath their soil

• Politics and Oil: Increasing reliance on Foreign oil in the late 60's and early 70's eventually lead to an "Embargo" of foreign oil to the US. Gasoline was perceived to be a scarce commodity, the price went up and the consumer waited in line. A knee jerk reaction to this temporary condition was to open the oil fields in Alaska to drilling in order to reduce our dependence on unreliable sources of foreign oil.

• The price of doing business this way is manifest by the rapid exploitation of a natural resource as well as environmental distaster in the form of The Exxon Valdez which covered a impressively large area ( go here for complete reports of the disaster )

• The oil fields in Alaska are not very extensive however and only had about a 25 year lifetime, at current consumption rates

• At current consumption rate, total US Oil reserves can power us for 12 more years; Alaska alone has only 5 more years left in it:
  • Known US Reserves as of 1990: = 36 billion barrels of oil
  • Total population is 250 million --> 144 barrels per person
  • Consumption Rate --> 3 billion barrels of oil per year --> 12 barrels per year per person
  • 144/12 --> 12 more years left

  • By 1995 the Reserve Estimate had dwindled to 22.5 billion barrels of oil and the cosumption rate remains the same
  • 22.5/3 = 7.5 years left so we are still on the trajectory
  • Decline of our Reserve
  • Where is the Oil in the US?:
    • Texas --> 26%
    • Alaska --> 26%
    • California --> 16%
    • Gulf Coast Off Shore --> 9%
    • New Mexico --> 3%
    • the remaining 20% is widely distributed

  • On a World Wide Basis there are 400 bbl per person. Timescale when this resource is used up is dependent on the world wide consumption rate which is very difficult to estimate. A worst case scenraio is the "Third World" aspires to the US consumption rate and this consumption rate then doubles: there would only be 400/24 = 17 years --> although this is a worst case, most best case scenarios offer a resource exhaustion timescale which is at most 3-4 times this value (e.g. 50-70 years) left

• Note: The production of oil in barrels per day is about the same for the US and Saudia Arabia. The US gets its production out of 600,000 wells while Saudi Arabia gets this out of 860 wells. This difference is because the US sits on an old oil field while Saudi Arabis is located over a very young and rich one. The environmental/ political consequences of such large production per well were easily manifest in Kuwait (see also - Smoke contours , Higher resolution image )

  

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