Agriculture and Environment: Agriculture and Environment 03.376 ERE3 Uwe Schneider


Contact: Contact Bundesstrasse 55, Room 022 Tel: 42838 6593 Email: schneider@dkrz.de Web: http://www.uni-hamburg.de/Wiss/ FB/15/Sustainability/schneider/


Wahlpflichtfach Umweltökonomie: Wahlpflichtfach Umweltökonomie ERE1 Environmental & Resource Economics ERE2 Global Environmental Problems ERE3 Valuation Theory ERE4 Agriculture and the Environment Sem Contemporary Environmental Problems Sem Issues in Environmental Economics


Class Topics: Class Topics Introduction Evolution of agriculture Environmental impacts of modern agriculture Global environmental change and agriculture Future of Agriculture


Exam: Exam One final exam will be given at the end of the course.


Economic Concepts: Economic Concepts Private profit maximization Externalities, Public Goods Non-point source analysis Governmental interference Dynamic optimization Agricultural Markets Welfare Economics


Environmental Themes: Environmental Themes Climate Water and nutrient cycles Air Quality Soil Quality Biodiversity Ecosystems


Agriculture: Agriculture Encyclopedia Britannica: “the science, art, or practice of cultivating the soil, producing crops, and raising livestock and in varying degrees the preparation and marketing of the resulting products” Derived from Latin agricultura, from ager field + cultura cultivation


Environment: Environment Encyclopedia Britannica: 1: the circumstances, objects, or conditions by which one is surrounded 2a: the complex of physical, chemical, and biotic factors (as climate, soil, and living things) that act upon an organism or an ecological community and ultimately determine its form and survival


Agriculture: Agriculture Strong dependency on natural resources Climate Soil Microorganisms, Animals Uncertainty about environmental conditions Weather Soil degradation Pest evolution


Global Land Allocation (FAO): Global Land Allocation (FAO) Earth surface = area of circle with radius of 12700 km Land 26% ~ (6500 km) Agriculture 10% ~ ( 4000 km) Permanent Pasture 7% ~ ( 3300 km) Arable Land 3% ~ ( 2100 km) Forest 8% ~ ( 3600 km)


Land Use Share (FAO): Land Use Share (FAO)


Ag-Population Share (FAO): Ag-Population Share (FAO)


Food Consumption (kg/head/day): Food Consumption (kg/head/day)


Crop Products: Crop Products After 10,000 years of settled agriculture and the discovery of some 50,000 varieties of edible plants, just 15 food crops provide 90% of the world's food energy intake. Three of them — rice, wheat and maize — are the staple foods of 4 billion people (FAO, World bank)


Calories from Livestock: Calories from Livestock Developed Developing Pork 5% 3% Beef 3% 1% Mutton 1% 0% Poultry 2% 1% Eggs 2% 1% Milk products 9% 3% Total 21% 9%


Environmental Impacts on Agriculture: Environmental Impacts on Agriculture Yield Potential Net productivity Pest impact Consumer Preferences Religions Culture Industry Input availability Nutrients Water Labor  Environment impacts cost of production and product demand


Agricultural Impacts on Environment: Agricultural Impacts on Environment Extensive ecosystem impacts species composition energy and nutrient cycles soil properties exchange between ecosystem


Environmental Problems of Agriculture: Environmental Problems of Agriculture Erosion Extinction of habitats and species Water pollution Desertification Salination Odor


Environmental Benefits from Agriculture: Environmental Benefits from Agriculture Species promotion Landscape formation (Openness, Esthetics, Recreation) Emission mitigation (GHG sink, biofuels, Soil decontamination)


Past Agriculture: Past Agriculture


Agricultural Challenge: Agricultural Challenge To sustain a (growing) society, food production must also be sustained How did previous societies cope environmental change in part caused by agriculture? Why did some societies survive and some collapse?


Collapsed Societies: Collapsed Societies Easter, Pitcairn, Henderson islanders Anasazi Mayas Greenland norse


Some Methods Revealing Past land use and land use changes: Some Methods Revealing Past land use and land use changes Archeology Radio carbon dating Pollen analysis (sediments) Middens (plantrich deposits from packrats) Tree ring analysis (dendrochronology)


Easter Island: Easter Island


Brief History of Easter Island: Brief History of Easter Island Colonization by humans around A.D. 900 by Polynesians Population maximum between 15-30 thousand Forest clearance (peak around 1400s, finished by 1600s, soil erosion) Population crash until 1700s (starvation, cannibalism) European contact (1st Captain Cook 1774) Epidemics, Abductions (111 islanders left in 1872) 1888 annexed by Chile, 1966 islanders become citizen


Food and Resources: Food and Resources Early settlers 25 nesting seabirds (albatros, ...), at least 6 land birds, porpoises (common dolphin), rats, sea turtles, seals? Palm tree plus 21 other vanished species (many trees among them) Late inhabitants Sweet potatoes, yams, taro, bananas, sugar cane, chicken No trees


Late Agricultural Methods: Late Agricultural Methods Water dams Chicken houses Stone lined compost pits Stones for wind protection Lithic mulch agriculture to save water Replace hard surface crust Reduce evapotranspiration Soil shade


Causes of Population Collapse: Causes of Population Collapse Deforestation Destruction of bird populations Cultural factors (erection of stone statues requiring wood) Rat


Why did Easter islanders cut down all trees but other islanders didn‘t?: Why did Easter islanders cut down all trees but other islanders didn‘t? Mangareva, Cook and Austral Islands, main Haiwaiian and Fijian Island though largely but not completely deforested Tonga, Samoa, Bismarcks, Solomons, and Makatea remain largely forested


Deforestation on Pacific Islands: Deforestation on Pacific Islands Deforestation is more severe on: Dry islands than on wet islands, Cold high-latitude islands than warm equatorial islands Old volcanic islands than young volcanic islands Islands without aerial ash fallout than islands with it Islands far from Central Asia‘s dust plume than islands near it Islands without Makatea than islands with it Low islands than high islands Remote islands than islands with near neighbors Small islands than big islands


Easter Island: Easter Island Third highest latitude Among the lowest rainfalls Lowest volcanic ash fallout Lowest Asian dust fallout No makatea Second greatest distance from neighboring islands Among lower and smaller islands of 81 studied


Similar fates: Similar fates Nihoa, Necker islands have similar bad conditions No humans Only one palm tree species left


The Anasazi: The Anasazi


Collapses in U.S. Southwest: Collapses in U.S. Southwest Mimbres (~A.D. 1130) Chaco Canyon, North Black Mesa, and the Virgin Anasazi (middle or late 12th century) Mesa Verde and the Kayenta Anasazi (~A.D. 1300) Mogollon (~A.D.1400) Hohokam (~15th century)


U.S. Southwest environement: U.S. Southwest environement Low and unpredictable rainfall Quickly exhausted soils Slow forest regrowth Recurring droughts and streambed erosion at large intervals


Coping with limited water: Coping with limited water Dryland agriculture (higher elevations: Mogollon, Mesa Verde) Ground water access (canyon grounds: Mimbres, Chaco Canyon) Water collection in ditches or canals (Hohokam: hundreds of miles of secondary canals branching off a main 12 mile canal 16 feet deep, 80 feet wide) Shifting agriculture (allow soil, vegetation, game to recover)


Environmental Problems: Environmental Problems Population explosion in wet (good) decades leading to complex societies Arroyo cutting Dropping water tables (Anasazi Salinization (Hohokam) Soil nutrient exhaustion (Mogollon) Deforestation (pinyon nuts, timber – Anasazi) Droughts


The Mayas: The Mayas


Mayas: Mayas Villages and pottery (1000 B.C.) Substantial buildings (500 B.C.) Writing (400 B.C.) Classic period (A.D. 250) Maya collapses (9th century)


Maya Sites: Maya Sites


Maya Environment: Maya Environment Seasonal tropical forest / seasonal desert Rainfall highly variable North to south of Yukatan (450 – 2500 mm) Elevation increases from north (25m) to south


Maya Food: Maya Food Corn (70%), beans Stingless bee for honey Dog, Turkey, Muscovy Duck Deer, fish Overall, little meat consumption


Maya Agriculture: Maya Agriculture Slash-and-burn (swidden agriculture)? Terracing of hill slopes Irrigation systems, canals Draining waterlogged fields, dumping muck and water hyacints onto fields Use canals for wild fish and turtles Other undiscovered means of intensification


70% of Mayas were peasants: 70% of Mayas were peasants Little protein Corn No large animals Relatively low productivity Humid climate limits storing No animal power for plowing or transport


Maya Climate Change: Maya Climate Change Relatively wet (5500 B.C. – 500 B.C.) Dry (475– 250) Wet (250– A.D. 125) Dry (125 –250) ... Preclassic collapses (El Mirador and other sites) Generally Wet (250 –760) Drought around 600 … Decline of Tikal and other cities Intense droughts (760-761, 810-820; 859-862, 907-913) … 99% of southern lowland population disappeared


Maya Collapse: Maya Collapse High population Deforestation and hillside erosion Increased warfare Climate change Failure of Maya to perceive and solve the problems


Summary: Summary Past agricultural societies collapsed because they lived in fragile environments they adopted non-sustainable methods they did/could not adjust in the light of external or human induced environmental change