WEEK 7

1. Lecture slides and notes:

Overview

• Agriculture - review of impact
• Energy, agriculture and society
• The "green revolution"
• Impacts of food production
• Transition to sustainable food economy
• Food vs. fuel
• Intro to world views

A. Impact

I=PAT equation

agriculture has a big impact

water - largest user

energy - 17% of all commercial energy in the US

emissions - 20% of CO2 emissions, 55% of methane

 

nexus of water, soil and energy

major portion of water budget

substantial (but not majority) portion of global energy budget

amount of land in production

image from http://foodfreedom.wordpress.com/2009/11/22/extinctions-over-population-and-the-profit-paradigm/

of which 40% is seriously degraded (wiki reading on Agriculture)

1/3 of population works in food production (ibid)

less than 5% of global aggregate GDPs (ibid)

B. Energy and society

progression around agriculture helped structure society

link

Types of agriculture

trade-offs between: machine capital, human labor, energy, chemical costs, and land

• low-technology farming
  • smaller
  • less productive
  • subsistence or local market only
• intensive agriculture
  • high human labor
  • maybe fertilizer costs
  • low to none traction
  • small land use
• industrial agriculture
  • low human labor
  • high traction and fertilizer costs
  • and machinery
  • can use lower grade soil but needs lots of it

another description (Pollan)

• industrial
• industrial organic
• artisan - smaller scale

C. The "Green Revolution"

Brought together:

• plant genetics
  • higher yield grains and rice
  • less stalk more grain
  • hardier for harvesting
• availability of irrigation
  • higher water demand
• use of petrochemicals
  • fertilizers (N and P)
  • herbicides and pesticides
  • traction

benefits:

• meeting food demand for many developing countries avoiding famines
• food security
• excess food for income

disadvantages:

• moving toward fewer varieties - depleting natural range of crops
• dependence on irrigation, more severe impact when there is a drought
• dependence on energy subsidies

 

indirect effects of these process

• water consumption
• lake eutrophication from runoff - case study

D. Impacts from food choices

not in the food itself but in the embodied or life-cycle energy

people may consume more goods, but bulk food consumption stays the same

however, different foods may require more or less water or energy

• examples from last week on the embedded water in foods (water embedded in food)
• energy in foods (about 10 * as much as nutritional)
  • 68 kcal of fossil fuel energy to make 1 kcal worth of pork
  • 35 kcal of fossil fuel energy to make 1 kcal worth of beef
  • references - link
  • high and low life cycle energy input for food can result in 5 fold difference
  • animal products range over about 4 fold range, so the particular recommendation for saving energy needs to take that into account
  • clams 27 MJ per portion, down to fresh cooked local cow at 3.2 MJ per portion
  • 27 MJ = 6480 kCal of embodied or life-cycle energy
  • link
• Ecotrust calculations show that air transported fresh salmon costs 57 times more CO2 than frozen

 

E. Transition to a sustainable and secure food system

sustainable food production

details next lecture

food security

• amount of food
• types of food available vs. nutrition
• economics
  • fuel
  • fertilizer
  • land ownership issues
• risks in the distribution system
• sensitivity to disruption from climate

 

F. Food vs. Fuel controversy

bio-fuels are competing with food production

• water
• land

environmental choice, economic incentives and policies play a big role

• tax credits
• carbon incentives
• rules that require proportion of fuel to be biodiesel of ethanol

impact on land use and biodiversity

Canola plants in Oregon

Values and World Views - intro for next section

How do people make decisions.

World Views

• relative to sustainability
• culture theory and views of risk and control
• more world view descriptions

World views, risk and uncertainty

• van-asselt-rotmans-2002 notes part A

2. In-class assessment:

3. Reading in the text - "Multiple Perspectives and Approaches to Complex Environmental Problems"

Chapter 11: Values and World Views

 

4. Readings from Wikipedia and Encyclopedia of Earth:

http://en.wikipedia.org/wiki/Intensive_farming

http://www.eoearth.org/article/Green_Revolution

http://en.wikipedia.org/wiki/Sustainable_agriculture

 

 

5. On-line activities:

Videos:

• food miles
• food and energy
• Walmart's statement on food miles

 

Simulations:

• Food miles calculator
• The CO2 impact per kg of food is related to the transport costs and fuel used.
• compare some foods that you like from exotic places such as coffee
• understand that air is more expensive per km but also likely to fly more km than you would use for a truck
• don't get too upset that they don't calculate the costs for cargo bikes (image and bike from a Portland bikebuilder http://www.metrofiets.com/ )

 

Case study or Example:

• Swedish food life cycle costs
• understand the methodology, what energy use they count and what they don't
• compare a few foods that are similar in nutrition but very different in life cycle energy costs

 

 

6. Learning objectives:

week 7 learning objectives

 

7. Link to the on-line assignment:

go to D2L