Food The major limiting factor to human population growth The major limiting factor to human population growth Depends on environment and socio- political.

FoodFood

• The major limiting factor to human The major limiting factor to human population growthpopulation growth

• Depends on environment and socio-Depends on environment and socio-political issuespolitical issues

• Right now distribution is the main Right now distribution is the main problemproblem

• If the human population continues to If the human population continues to grow, quantity will be the problemgrow, quantity will be the problem

Where does our food come Where does our food come from?from?• Land crops and livestock!Land crops and livestock!

– Only 14 species of plantsOnly 14 species of plants

• Cash cropsCash crops

• Subsistence cropsSubsistence crops

• Top food crops:Top food crops:– Wheat, rice, maize, Wheat, rice, maize,

potatoespotatoes

Earth as an Applehttp://www.farmland.org/Flash/appleEarth.html

How much food do people How much food do people need?need?• 2600 calories/day2600 calories/day• If they don’t get If they don’t get

this: this: undernourishmentundernourishment

• If they don’t get If they don’t get specific nutrients: specific nutrients: malnourishmentmalnourishment– Marasmus, Marasmus,

kwashiorkor, chronic kwashiorkor, chronic hungerhunger

• On the flip side of On the flip side of the coin: obesitythe coin: obesity

NutritionNutrition•UndernourishmentUndernourishment = = •too few caloriestoo few calories•(especially developing (especially developing world)world)

•OvernutritionOvernutrition = = •too many caloriestoo many calories•(especially developed world)(especially developed world)

•MalnutritionMalnutrition = lack of = lack of nutritional requirementsnutritional requirements•(causes numerous diseases, (causes numerous diseases, esp. in developing world)esp. in developing world)

Figure 9.2

Percentage of population affected Percentage of population affected by undernutrition by country, by undernutrition by country, according to United Nations according to United Nations statisticsstatistics

Global food securityGlobal food security

•The world still has 800 million hungry The world still has 800 million hungry people, largely due to inadequate people, largely due to inadequate distribution.distribution.

•Global Global food securityfood security is a goal of is a goal of scientists and policymakers worldwide.scientists and policymakers worldwide.

HOW TO FEED THE WORLDHOW TO FEED THE WORLD

• http://www.youtube.com/watch?v=QloMOOG-bbE

The The best best waysways

• ““Give a man a fish Give a man a fish and you feed him and you feed him for a day. Teach a for a day. Teach a man to fish and you man to fish and you feed him for a feed him for a lifetime.” –Lao Tzulifetime.” –Lao Tzu

• Create systems Create systems where food is grown where food is grown and distributed and distributed locallylocally

AgricultureAgriculture

2,000

1,500

1,000

500

0

Gra

in p

rod

uct

ion

(mill

ion

s o

f to

ns)

1950 1960 1970 1980 1990 2000 2010

Total World Grain Production

Year

400

350

300

250

150

Per

cap

ita

gra

in p

rod

uct

ion

(kilo

gra

ms

per

per

son

)

1950 1960 1970 1980 1990 2000 2010

World Grain Production per Capita

200

Year

Cal

ori

es p

er d

ay p

er p

erso

n3,700

3,500

3,300

3,100

2,900

2,700

2,500

2,300

2,100

1960

1970

1980

1990

2000

2010

2030

Year

Developed countries

World

Developing countries

Figure 14-3Figure 14-3Page 276Page 276

Croplands

• Help maintain water flow and soil infiltration

• Provide partial erosion protection • Can build soil organic matter

• Store atmospheric carbon

• Provide wildlife habitat for some species

Ecological Services Economic Services

• Food crops

• Fiber crops

• Crop genetic resources

• Jobs

Natural Capital

Croplands

Ecological Services

Economic Services

•Help maintain water flow and soil infiltration

•Provide partial erosion protection

•Can build soil organic matter

•Store atmospheric carbon

•Provide wildlife habitat for some species

•Food crops

•Fiber crops

•Crop genetic resources

•Jobs

Biodiversity Loss

Loss and degradation of habitat fromclearing grasslands and forests anddraining wetland

Fish kills from pesticide runoff

Killing of wild predators to protectlivestock

Loss of genetic diversity fromreplacing thousands of wild cropstrains with a few monoculture strains

Soil

Erosion

Loss of fertility

Salinization

Waterlogging

Desertification

Air Pollution

Greenhouse gas emissions from fossilFuel issue

Other air pollutants from fossil fuel use

Pollution from pesticide sprays

WaterWater waste

Aquifer depletion

Increased runoff andflooding from land clearedto grow crops

Sediment pollution fromerosion

Fish kills from pesticiderunoff

Surface and groundwaterpollution from pesticidesand fertilizers

Overfertilization of lakesand slow-moving riversfrom runoff of nitrates and phosphates fromfertilizers, livestockwastes, and foodprocessing wastes

4% 2% 6% 5%

17% of totalcommercialenergy use

Crops Livestock Food processing Food distribution and preparation

Food production

Producing and eating meatProducing and eating meat

• Land use issuesLand use issues– More land neededMore land needed

•More land needed for grazing than grain More land needed for grazing than grain productionproduction

•Acre of grain for human consumption feeds Acre of grain for human consumption feeds more than an acre used for grazingmore than an acre used for grazing

•Land needed to grow forage AND raise Land needed to grow forage AND raise animals: Housing, food storage and waste animals: Housing, food storage and waste disposaldisposal

Producing and eating meatProducing and eating meat• Energy issuesEnergy issues

– Eating at a lower trophic levelEating at a lower trophic level• More solar energy available to humans, less lost More solar energy available to humans, less lost

through trophic transferthrough trophic transfer

– Storage of grain less energetically expensive Storage of grain less energetically expensive than processing and storing meatthan processing and storing meat• Transport, slaughter and refrigerationTransport, slaughter and refrigeration

– Energy costs associated with meat productionEnergy costs associated with meat production• Producing grain for livestockProducing grain for livestock

– Fertilizers, irrigation, pesticides, farm machineryFertilizers, irrigation, pesticides, farm machinery

• Animal waste managementAnimal waste management– Pumping, treatment, transport, disposalPumping, treatment, transport, disposal

• Animal care and round up of free range livestockAnimal care and round up of free range livestock

Eating less meat: Pro and Eating less meat: Pro and ConCon• AdvantagesAdvantages

– Reduced risk of diseaseReduced risk of disease• CholesterolCholesterol

– Clogged arteriesClogged arteries– HypertensionHypertension– Heart diseaseHeart disease

– Reduced chemical Reduced chemical exposureexposure

• HormonesHormones• SteroidsSteroids• AntibioticsAntibiotics• Pesticides (Biomag!)Pesticides (Biomag!)

– Reduced exposure to Reduced exposure to diseasedisease

• Mad CowMad Cow• Salmonella/ E. coliSalmonella/ E. coli• ParasitesParasites

• DisadvantagesDisadvantages– Meat an excellent source Meat an excellent source

of proteinof protein• Essential amino acidsEssential amino acids

– Rice and Beans!Rice and Beans!• Difficult to get enough Difficult to get enough

protein without meatprotein without meat– Nutritional deficienciesNutritional deficiencies

• Kwashikor: ProteinKwashikor: Protein• Blindness: Vit. ABlindness: Vit. A• Pollegra: Vit. BPollegra: Vit. B• Anemia: IronAnemia: Iron• Inadequate essential fats Inadequate essential fats

balancebalance

How do we address world How do we address world hunger?hunger?• Policy and behavioral Policy and behavioral

changeschanges

• Eat lower on the food Eat lower on the food chain? chain?

• Modify food Modify food distributiondistribution

• Improve Improve infrastructureinfrastructure

• Economic policiesEconomic policies– End subsidiesEnd subsidies

To feed the world….To feed the world….• Conservation of matterConservation of matter

– Available resources limit agricultural productionAvailable resources limit agricultural production– Nutrients used by plantsNutrients used by plants

• Nitrates: Protein and DNANitrates: Protein and DNA• Phosphates: DNA, RNA, ATPPhosphates: DNA, RNA, ATP

– Soil degraded as nutrients removed by harvestSoil degraded as nutrients removed by harvest• Conservation of EnergyConservation of Energy

– Trophic level energy lossTrophic level energy loss• Vegetarian vs Carnivorous dietsVegetarian vs Carnivorous diets

• Green revolutionGreen revolution– Increase yield per acreIncrease yield per acre– MonocultureMonoculture– Intensive tillage = soil erosionIntensive tillage = soil erosion– Requires Requires

• Energy: Emissions and oilEnergy: Emissions and oil• Fertilizers and pesticides: Toxic pollution, soil salinizationFertilizers and pesticides: Toxic pollution, soil salinization• Irrigation: Water rights and usageIrrigation: Water rights and usage