What are the THREATS to global food security? Flashcards
Key Ideas ~ risks to food security can be identified to highlight the most vulnerable societies & the food system is vulnerable to SHOCKS
Desertification
The outcome of persistent LAND DEGRADATION
Most often in DRYLND environments
Frequently caused by:
- Deforestation
- Overgrazing
- Overcultivation
STATISTICS on desertification
- 168 countries are affected.
- Every year , an area 3x the size of Switzerland becomes desertified.
- 74% of the poorest people ate directly impacted by desertification.
Cause of desertification ~ Changing Farming Practices
Traditional dryland economies:
- Have been based on SMALL-SCALE methods
- SUSTAINABLE and suited to the limited CARRYING CAPCITY of these ecosystems.
Now more intensive farming methods are used due to :
- Population pressures e.g Niger & Chad
- Urbanisation & increase in agricultural exports e.g Kenya
This has led to:
- Abandoned fallow periods & crop rotation~ depletion of soil nutrients.
- Clearance of surface vegetation ~ wind and water erosion, carries top soil away , leaving sand & dust.
Cause of desertification ~ Water Scarcity
- IRRIGTION PROJECTS are used to meet the demand of the increased intensity of cultivation.
- However, they are often unsuitable , poorly manged & underfunded.
Example ~ LAKE CHAD
- Borders Niger , Nigeria & Cameroon,
- Shrunk from 25,000km2 to 2000km2 in 30 years.
CAUSES:
- High demand for irrigation water
- Diversion of water for large-scale irrigation projects.
- Building of dams for a water store
Cause of desertification ~ Demand For Fuelwood
- Has a high demand as it is used for cooking and lighting.
- Clearing of trees :
- Greatly impacts deforestation
- Increase the vulnerability of soils to water
& wind erosion .
African counties that have a high dependency on fuelwood and the % used for energy:
Burkina Faso ~ 90%
Chad ~ 89%
Mali ~ 80%
Cause of desertification ~ Fires
- Previously used in SMALL AREAS to:
- release nutrients stored in vegetation
- stimulate the growth of new pasture.
- Now used to clear large areas of new farmland causing WIDESPREAD land degradation.
Causes of desertification ~ Increased Periodic Drought & Changing Rainfall Patterns
- Significant decline in precipitation, in the Sahel, has resulted in periodic drought.
- Dryland areas have a vulnerability to unpredictable rainfall patterns:
- Amount
- Distribution
- Seasonal timing
- Any changes to these factors can lead to OVER-EXPLOITATION of scarce resources, causing further degradation.
Desertification ~ ENVIRONMENTAL impacts
EXHAUSTION OF SOIL NUTRIENTS:
- due to continual cropping and fewer fallow periods.
- decreases soil fertility
- leads to food shortages
SOIL EXPOSURE:
- Soil nutrients are lost through wind & water erosion.
- Reduces yields
LOSS OF BIODIVERSITY:
- vegetation is removed
- impacts the functioning of ecosystems
INCREASED DUST FORMATION:
- disrupts cloud formation and rainfall patterns.
- increase the vulnerability to fluctuating harvests
Desertification ~ ECONOMIC impacts
REDUCED AVAILABILITY OF FUELWOOD:
- Increased purchase of kerosene
- causes health issues such as sore eyes
FOOD SHORTAGES:
- A risk of a growing dependency on food aid.
LOSS OF JOBS:
- The income of pastoralists is reduced
- forced to find an alternative source of income.
WIDESPREAD RURAL POVERTY:
- leads to food security issues and less people can afford food.
Desertification ~SOCIAL & CULTURAL impacts
FORCED MIGRATION:
- due to scarcity of productive farmland
INCREASED MALE OUT-MIGRATION:
- Have to find an alternative income
- women take over the responsibility of farming & water management.
LOSS OF TRADITONAL KNOWLEDGE & SKILLS:
- leads to falling yields.
Approach to Avoid Desertification
DIVERSIFY LAND USE:
- generates an income through alternative livelihoods
- Examples ~ greenhouse agriculture , tourism.
MIXED FARMING PRACTICES:
-livestock rearing & cropping are combined
- allows more efficient recycling of nutrients
MAINTAINING VEGETATION COVER:
- protects soils
- restores soil fertility though the use of organic fertilisers.
REDUCE CLEARANCE OF TREES:
- develop non-wood energy supplies
- naturally available in dryland ecosystems
- Examples ~ solar , biogas & wind power
Water scarcity with two examples
- Less than 1% of all water is available for human use
- AGRICULTURE consumes 68% of water
- Of the water available for agriculture, 60% is lost through poor irrigation systems & high levels of evapotranspiration.
AUSTRALIA:
- Its volume of international trade in wheat & dairy products , is sufficient to affect GLOBAL PRICES
- Extreme weather events, driven by El Nino, bring periodic droughts
- Water-efficiency measure :
- cap on water extraction
- withdrawn subsidies for irrigation
- capped trade in water between framers.
KENYA:
- Mulching ~ laying plant leaves between cultivated crops , reduce soil erosion& retain water
- Drip Irrigation ~ reduce loss by evaporation
Extreme Weather Events
- Becoming more FREQUNET & SEVERE
- WARMING temperatures cause an increase in water evaporation, leading to intense rainfall & the greater RETENTION of heat energy.
GLOBAL LINKS:
- Food production accounts for almost one-third of greenhouse gas emissions e.g CO2 from land clearance
- Modification of global food system:
- extended/ reduced growing seasons
- increased frequency of drought, coastal floods and wildfires
- Destruction of crops and key infrastructure which disrupts distribution, exacerbates poverty & threatens food security
Examples of extreme weather events
HEATWAVES:
- A period of several days or weeks of abnormally hot weather
- Critical if it coincides with key stages of crop development
2018 EUROPE:
- Countries in central and eastern Europe
- Worst harvest since WW2
- Rising food prices
DROUGHT:
- Results in crop failure & reduced water quality and quantity
- leads to further environmental impacts e.g soil erosion & rockfall.
2019 SOUTHERN AFRICA:
- Over 2 million people were in need of food aid following persistent drought
FLOODS:
- warming climate causes more heavy rainfall
- destroys crops , disrupts food distribution, erode soils and damages infrastructure.
UK:
- 35000 ha of high-quality arable land estimated to be flooded one every 3 years
- 58% of the most productive farmland lies within a floodplain
