240 likes | 396 Views
AP Environmental Science Mr. Grant Lesson 63. Raising Animals For Food: Livestock, Poultry, And Aquaculture & Sustainable Agriculture. Objectives:. Define the term genetically modified (GM) organisms . Assess feedlot agriculture for livestock and poultry.
E N D
AP Environmental Science Mr. Grant Lesson 63 Raising Animals For Food: Livestock, Poultry, And Aquaculture & Sustainable Agriculture
Objectives: • Define the term genetically modified (GM) organisms. • Assess feedlot agriculture for livestock and poultry. • Weigh approaches in aquaculture. • Evaluate sustainable agriculture. • TED - Louise Fresco shows us why we should celebrate mass-produced, supermarket-style white bread. She says environmentally sound mass production will feed the world, yet leave a role for small bakeries and traditional methods.
Define the term genetically modified (GM) organisms. • Genetically Modified (GM) Organisms: • An organism that has been genetically engineered using a technique called recombinant DNA technology.
Assess feedlot agriculture for livestock and poultry. • As wealth has increased, so has the consumption of animal products. • Eating animal products leaves a greater ecological footprint than eating plant products. • Feedlots create waste and other environmental impacts, but they also relieve pressure on lands that could otherwise be overgrazed.
Consumption of animal products is growing • As wealth and commerce increase, so does meat, milk, and egg consumption • Since 1950, global meat production has increased fivefold and per capita meat consumption has doubled • Domestic animals raised for food increased from 7.2 billion in 1961 to 24.9 billion in 2008
Our food choices are also energy choices • Eating meat is far less energy efficient than eating crops • 90% of energy is lost from one trophic level to the next • Eating lower on the food chain feeds more people • Some animals convert grain into meat more efficiently than others
Environmental ramifications of eating meat • Land and water are needed to raise food for livestock • Producing eggs and chicken meat requires the least space and water • Producing beef requires the most
Resources needed for livestock production When we choose what to eat, we choose how we use resources
Feedlot agriculture • Feedlots (factory farms) = also called Concentrated Animal Feeding Operations (CAFOs) • Huge warehouses or pens deliver food to animals living at extremely high densities • Over half of the world’s pork and most of its poultry U.S. farms house hundreds of thousands of debeaked chickens in crowded cages
High consumption leads to feedlot agriculture • Traditional agriculture keeps livestock on grasslands • Feedlot animals are fed grain grown on cropland • One-third of the world’s cropland is fed to livestock • Feedlot agriculture allows economic efficiency • Greater production of food • Unavoidable in countries with high meat consumption, like the U.S. • Reduced grazing impacts on the land • Manure can be applied to fields as fertilizer
Livestock agriculture pollutes water and air • Feedlots produce huge amounts of manure and urine • Causing eutrophication • Waterborne pathogens sicken people • Crowded, dirty housing causes outbreaks in disease • Heavy use of antibiotics, hormones, heavy metals • Chemicals are transferred to people • Microbes evolve resistance to antibiotics • Air pollution: odors, ammonia (acid rain) • More greenhouse gases (CO2, methane, nitrous oxides) than automobile emissions
Weigh approaches in aquaculture. • Aquaculture provides economic benefits and food security, relieves pressures on wild fish stocks, and can be sustainable. • Aquaculture also gives rise to pollution, habitat loss, and other environmental impacts.
We raise fish on “fish farms” • World fish populations are plummeting • Technology and increased demand • Aquaculture = raising aquatic organisms in a controlled environment • Species are raised in open-water pens or land-based ponds
Aquaculture is growing rapidly • Over 220 freshwater and marine species are grown • The fastest-growing type of food production • Provides ¾ of the world’s fish, ½ of the shellfish • Most widespread in Asia
Benefits: A reliable protein source Can be sustainable Reduces pressure on overharvested wild fish Energy efficient Drawbacks: Diseases require expensive antibiotics Lots of waste Uses grain Escaped GM fish introduce disease or outcompete wild fish The benefits and drawbacks of aquaculture
Evaluate sustainable agriculture. • Organic agriculture exerts fewer environmental impacts than industrial agriculture. It comprises a small part of the market but is growing rapidly. • Locally supported agriculture, as shown by farmers’ markets and community-supported agriculture, is also growing. • Mimicking natural ecosystems is a key approach to making agriculture sustainable.
Sustainable agriculture • Industrial agriculture may seem necessary • But less-intensive agricultural methods are better • Sustainable agriculture = does not deplete soil, pollute water, or decrease genetic diversity • Low-input agriculture = uses smaller amounts of pesticide, fertilizers, growth hormones, water, and fossil fuels than industrial agriculture • Organic agriculture = uses no synthetic fertilizers, insecticides, fungicides, or herbicides • Relies on biological approaches (e.g., composting and biocontrol)
Organic approaches reduce inputs and pollution • Organic Food Production Act (1990) establishes national standards for organic products • The USDA issued criteria in 2000 by which food could be labeled organic • Some states pass even stricter guidelines for labeling • California, Washington, Texas • Nearly 500 organizations offer certification services
The benefits of organic farming • Farmers have lower input costs, enhanced income, reduced chemical pollution, and soil degradation • They practice stewardship to the land • Obstacles include risks and costs of switching to new methods • Consumers are concerned about pesticide’s health risks • They want to improve environmental quality • Obstacles include the higher price of organics
Organic agriculture is booming • Organic farmers can’t keep up with demand • U.S. consumers pay $22.9 billion/year • Production is increasing • 1.8 million ha in the U.S.
Governments can support organic farming • In 1993, the European Union adopted a policy supporting farmers financially during conversion to organic farming • The U.S. offers no support so organic production lags • The 2008 Farm Bill gives $112 million over 5 years for organic agriculture • Many farmers can’t switch, because they can’t afford the temporary loss of income • In the long run, organic farming is more profitable than conventional farming
Locally supported agriculture is growing • Sustainable agriculture reduces fossil fuel use from long-distance transport of products • Food is chemically treated for freshness and color • Farmers’ markets = provide fresh, locally grown food • Community-supported agriculture (CSA) • Consumers pay farmers in advance • Consumers get fresh food • Farmers get a guaranteed income
Sustainable agriculture mimics natural ecosystems • Ecosystems operate in cycles • Stabilized by negative feedback loops • Small-scale Japanese farmers add ducks to rice fields • Ducks eat weeds, insects, snails • Their waste is fertilizer • Their paddling oxygenates the water • Fish and ferns provide food and habitat
TED Video A powerful thinker and globe-trotting advisor on sustainability, Louise Fresco says it's time to think of food as a topic of social and economic importance on par with oil -- that responsible agriculture and food consumption are crucial to world stability. Louise Fresco on feeding the whole world (18:04) "There is no technical reason why we could not feed a world of nine billion people. Hunger is a matter of buying power, not of shortages."