GEOG_130 (6/19)

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Department
Geography
Course
GEOG 130
Professor
Nicole C.List
Semester
Summer

Description
GEOG 130 (6/19) Climate Change and the World Food System Key 21st Century Questions ● How climatic changes transform/threaten today’s global food system ● Variability of these exposure/vulnerability ● How food system itself drive climate change ○ How to reduce these emissions ● Unintended livelihood consequences of current climate change policies & “green economy” Global Warming ● Warming of climate system is unequivocal ● Increase of global temperature ● Shrinking of sea ice ● Decline of mountain glaciers & snow cover ● Increase of pollen Interpreting Climate Change Impacts & Consequences: The Global Food System, Human Livelihoods How Agriculture is Sensitive to Climate Change ● Global temperature and precipitation increases but uneven regional changes (some places may cool or become drier) ○ More active climate system = more precipitation (evaporation of water) ○ Possible shutdown of gulf stream ● Stressors include: (dependent on where changes take place) ○ More extreme events ○ Decreased snow melt ○ New disease/pest exposures ● Geographically uneven impacts ○ Cold weather regions may “win”? ○ Agricultural deltas threatened by sea level rise ● Endemic uncertainty? ○ Past does not become a predictor Climate Change & US Agriculture (dependent on where it is) ● Potential short-term yield increases; long-term uncertainties ● US regional differences ● Hard-to-measure threats ○ Wind, water damage from severe weather ○ Increased pest & crop disease ○ More invasive species ○ More frequent & intense drought ● CA Agriculture ○ Loss of Sierra snowpack threatens irrigated agriculture (at worst, loss to 20%) ○ Aggravated ozone will damage crops ○ Threshold crops (wine grapes) will suffer ○ Pest ranges will expand Fisheries Sensitivity ● Climate change impacts ○ Warmer oceans, less mixing (= less nutrients) ○ Ocean acidification (Increased CO2 in atmosphere = reaction) ● Effects/stressors include: ○ Major coral bleaching/loss ○ Increased parasites/microbes ○ Fish are a critical global protein source, especially in poorer regions ○ Large, industrial fisheries Social Vulnerability & Adaptation ● Adaptive :solutions: recommended in “Farmed Out”Biello (2009) ○ Developing agrotechnology for specific group tolerances A New Green Revolution ● Familiar “solutions” ○ Increased agricultural research into drought-resistant crop varieties ○ Crop and livestock productivity-enhancing research (biotechnology) What Drives “Vulnerability climate change?” ● Geographically uneven physical exposure... but even human geography matters even more ● “Climate change vulnerability” as ○ Dependence on primary sector livelihoods ○ Existing poverty, livelihood insecurity ○ Land dispossessions ● Would a new green revolution help or worsen the situation? Framings Matter ● Climate change in real world contexts ● Biello (2009) ○ Increasing frequency of famines → raising prices of staple foods ○ “Population pressure” model ■ How is this framing neo-Malthusian? ○ Regional drought impacts world market ● Post subprime collapse → 2007-2008 agriculture commodities bubble and global land grab ○ Big corporations buying into farming Global South regions ● “Opportunity of investing in climate change” ○ Investment banks make money off of climate change/adaptations “Climate change justifications” ● Biofuels and carbon offsets (“forestry”) ● Climate crisis justifications = food, water security → general land banking, farmland buy- ups Vulnerability ● Rural poor dispossessed of land/water resources under customary tenure ● Loss of access to grasslands, forests, marshlands customarily held as common property ● Commercial leaseholds over previously untitled land = foreclosing opportunities for communities to seek and secure title ● Large-scale irrigation schemes = competition & conflict w/ downstream water users Food System as Greenhouse Gas (GHG) Emissions Source ● Industrialization ○ Fertilizers ○ Pesticides ○ Irrigation ○ Machinery ● Consolidation ○ Fewer, larger operations ○ Concentrated in a few US regions ● Livestock intensification via CAFOs ○ Grain-fed replaces grass-fed ○ Large, liquid manure systems (anaerobic lagoons) replace daily spread World Food System Trends ● Longer food transport ● More refrigeration ● Increased processing ● More counter-seasonal produce ● Increased meat consumption Greenhouse Gas (GHG) Emissions: On-Farm ● Nitrous oxide (N2O) from nitrogen application to soils (agricultural soil management) ● Methane (CH4) from livestock digestion (enteric fermentation) ● CH4 and N2O produced by managed manure systems ● CO2 N2O from Agricultural Soil Management (58% total) ● Industrial fertilizer decomposition ○ Wasted nitrogen released to water and air ○ US growth slowed due to regulation ○ Affected by practices, scale of agriculture ● Livestock manure decomposition ○ Applied as organic fertilizer or deposited on pasture ○ Produced via combined, aerobic/anaerobic decomposition ○ Proportional to livestock populations ● Other sources ○ Less significant; poorly understood ● Metabolic Rift! CH4 from Livestock Digestion (28% total) ● Ruminant livestock produce CH4 as a digestion by-product ● Cattle most important source ○ Beef cattle: 71% emissions ○ Dairy cattle: 24% emissions ● Affected by ○ Cattle population ○ Feed: more digestible feeds (grain, high quality pasture) produce lower Ch4 CH4 and N2O from Manure Management (12% total) ● CH4 from anaerobic manure decomposition ○ 34% increase 1990-2006 ○ Driven by increase in large, confined operations w/ CH4-intensive liquid manure systems ○ Primarily dairy cattle and swine operations ● N2O from aerobic/anaerobic manure decomposition ○ Much smaller than CH4 emissions ○ Complex generation process ○ Affected by total livestock populations GHG Emissions: Food System ● Life-cycle analyses capture full GHG emissions, including energy ○ On-farm = only 6.4% of US emissions in 2006 ○ Total US food system = 16-20% of US energy use
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