Sustainability. Sustainability of the Food System. Financial & Business Stresses. Social Issues. Environmental Issues. Environmental Issues 6/11/2015

Transcription

1 Sustainability Sustainability of the Food System Jim Thompson Financial/business Social Environmental Financial & Business Stresses Cost of inputs Market competition Labor availability Cost & availability of capital Regulations: labor, taxes, environmental, food safety Import/export restrictions Social Issues Illegal immigrants. Poor wages & local poverty. Retirement & health benefits for workers and growers. Effects on children child care, time parents are away from home. Human Health (Disability life, years) Ecosystem Quality (Potential disappeared species, fraction/m2. yr) Resources (Additional energy to extract, MJ/kg ) Environmental Issues Respiratory effects (organics) Respiratory effects (inorganics) Climate change Ionizing radiation Ozone layer depletion Acidification/eutrophication Ecotoxicity Land use Mineral depletion Fossil fuel depletion Environmental Issues Requires evaluation of environmental effects of all system inputs, including effects of supplying all resources and equipment used in system. Assumptions and data quality can make big differences in results. 1

2 US Greenhouse Gas Emissions US Greenhouse Gas Emissions Sector % Industry 29 Transportation 27 Commercial 18 Residential 17 Agriculture 8 Food system is 20 30% of total EIPRO 2008 Sector % Industry 29 Transportation 27 Commercial 18 Residential 17 Agriculture 8 US EPA % of GHG emissions are from fossil fuel consumption. US EPA 2010 Options for Reducing Energy at Home An Energy Star refrigerator bought today uses 50% less electricity than typical 1993 model. Most efficient and small refrigerators = 0.5 kwh/day. Large refrigerators with side-by-side freezer and ice makers = 4 kwh/day. Options for Reducing Energy at Home Reduce food waste 26% of food purchased is not eaten in U.S. Reduce food intake In 1970 caloric intake was 2170 kcal/day In 2007 intake increased 28% to 2775 kcal/day 2

3 Transportation Energy Use California is far from the main US market MJ/t-km Method 1970 s* Current Ship ** 0.2*** Railroad Highway truck Air *Thompson, 1985 **Network for Transport & Energy *** Webber & Mathews 2006 Transportation Experimental Highway Truck Method travel w/ equal energy use Ship 3800 Railroad 2400 Highway truck 740 Air 43 Car w/5kg of produce mpg vs. 5-8 mpg for conventional 4000 lb more load capacity Rail Traditional rail companies. Railex 3PL service. Reduce Transport Energy Reduce trips to the store. Buy less air freighted produce. Imported product may not have the highest transport energy use. Nutrition is valuable and must not be left out of the calculations. 3

4 Food Choices & GHG Emissions Equivalent miles of Options auto driving 1. Reduce food miles to Replace red meat & dairy w/ chicken,fish, eggs 1 day/week 3. Replace red meat & dairy w/ fruit & vegetables 1 day/week Webber & Matthews 2006 Paper or Plastic? No clear choice between the two packaging systems. Processed vs Fresh Apples Handling method Energy use (MJ/t) Fresh 8,500 Canned juice 5,500 Energy Savings Processed product may have lower energy use than fresh. Canned sauce 9,900 Dried 5,100 Apple crisp prepared at home 14,400 Whittlesey & Lee,

5 Organic vs. Conventional Table grapes Use sulfur instead of other fungicides and organic fertilizer Same yields Rice Organic weed control is difficult Organic yields < 50% of conventional Energy use - conventional rice Kcal/ac (%) Mechanized operations Fertilizer Irrigation Other Total 3550 Energy use for Table Grapes Kcal/ac (%) Mechanized operations Fertilizer Irrigation Other Total 3550 Cervinka et al., 1974 Cervinka et al., 1974 Fertilizer Urea nitrogen has 15.3 times as much nitrogen per pound as poultry manure. Energy to move 15 trucks of dry poultry manure for 3 miles = energy embodied in I truck of urea nitrogen. Dry manure has embodied energy associated with collection and composting. Observations Need good information on energy use for a range of organic fertilizer sources. Weeds may cause low yield and consequently low energy efficiency for organic grains. Organic fruits & vegetables may have better energy efficiency than conventional. 5

6 Energy Conservation in Rice Drying Natural gas (therms/ton) Electricity (kwh/ton) 1976 Industry average Major cooperative Reducing Energy Use in Agricultural Production Improve yield per acre. Develop new cultivars with shorter growing seasons. Use efficient water application methods. Minimize fertilizer use. Minimize soil cultivation no till methods. Conclusions for Energy Consumers are responsible for the greatest portion of food energy use. Consumer choices are the greatest potential for savings. All parts of the system have and can further reduce energy consumption. 6