GEOG_130 (6/19)

7 Pages
Unlock Document

GEOG 130
Nicole C.List

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
More Less

Related notes for GEOG 130

Log In


Join OneClass

Access over 10 million pages of study
documents for 1.3 million courses.

Sign up

Join to view


By registering, I agree to the Terms and Privacy Policies
Already have an account?
Just a few more details

So we can recommend you notes for your school.

Reset Password

Please enter below the email address you registered with and we will send you a link to reset your password.

Add your courses

Get notes from the top students in your class.