Causes of Famine
AdvancedFamine is not mere food shortage: the world grows enough, but supply is uneven and access unequal. Drought, desertification, poverty, war and low-technology farming intertwine — and the Sahel–Southern California contrast shows how human factors decide agricultural fate.
- The world grows enough food; the problems are uneven supply and unequal access
- Famine = short supply + blocked access; causes link to economy, technology, society and environment
- Natural causes: drought, desertification, pests; human causes: poverty, war, population growth, low-tech farming
文體小知識：地理議題說明文——解釋饑荒的定義與多重成因，並以薩赫勒遊牧業與南加州灌溉農業對比自然與人文因素如何塑造農業特徵。
§Text Passage
1The world grows enough food for everyone, yet supply is deeply uneven: some regions overproduce while others chronically lack food. Nutrition and food consumption differ sharply across the globe, with developed regions consuming far more per head, and food trade tends to flow towards wealthy markets. Famine is therefore not only an agricultural problem but a double problem of supply and access.
2A famine is a disaster in which food in a region falls so short, for so long, that large numbers of people cannot obtain enough to eat and mass malnutrition and death follow. The curriculum links its causes to the economy, technology, society and the natural environment: natural disasters cut supply, poverty and unequal distribution block access, war wrecks farming and transport, and low-technology agriculture cannot withstand shocks. Short supply and unequal access interweave into the full picture of famine.
3Factors shaping a region's agriculture fall into two groups. Natural factors — climate, soils, vegetation and relief — set the basic conditions; human factors — economic, social, political and technological — determine how the conditions are used. Treat farming as a system: inputs of labour, seeds, water and fertiliser pass through production to yield food outputs; when two places with similar natural conditions differ hugely in output, the difference lies in human inputs.
4The Sahel lies on the southern edge of the Sahara: rainfall of only about 200–600 mm a year, swinging wildly between years, with nomadic herding and subsistence farming — and severe famine in the droughts of the 1970s. Southern California is just as dry, yet massive investment in water conveyance and irrigation, plus technology and markets, made it a highly productive irrigated farming region. The contrast shows that human factors, especially technology, matter more and more in agriculture.
1Summary 重點摘要
Famine is not mere food shortage: the world grows enough, but supply is uneven and access unequal. Drought, desertification, poverty, war and low-technology farming intertwine — and the Sahel–Southern California contrast shows how human factors decide agricultural fate.
2Vocabulary cards Vocabulary
A disaster in which severe, prolonged food shortage leaves large numbers of people without enough to eat, causing mass malnutrition and death.
The total food available to a region, shaped by local production, reserves and trade.
The condition of chronically lacking enough nutrients for health — famine's most direct consequence.
The degradation of land in arid and semi-arid areas, accelerated by overgrazing and overcultivation.
A farming way of life in which herders move with their livestock in search of pasture and water, common in the Sahel.
Grazing beyond the grassland's carrying capacity, preventing vegetation recovery and degrading land.
Farming that supplements rainfall with artificially conveyed water — the basis of Southern California's high output.
The whole farming system: inputs (labour, seeds, water, fertiliser) through production processes to outputs.
Natural conditions affecting farming — climate, soils, vegetation, relief — which set the basic possibilities.
Human conditions affecting farming — economy, society, politics and technology — whose influence keeps growing.
3Step by step Steps
- Step 1: The global mismatch of food supplyGlobal food supply is deeply uneven and mismatched with need: some regions overproduce — even keeping output up with subsidies — while others chronically lack food. Global differences in nutrition and consumption are stark, and trade patterns favour shipping food to wealthy markets. For example, North America exports huge grain surpluses, some going to animal feed and biofuels, while the Sahel fills its gap with imports and aid. Grasping this spatial mismatch is the first step in analysing famine: the question is not whether the earth can feed people, but whose table the food finally reaches.
- Step 2: Defining and recognising famineA famine is a disaster in which a region's food falls so short, for so long, that large numbers of people cannot get enough to eat, and mass malnutrition and death follow; it differs from a month of rising prices or a poor harvest by its breadth, duration and lethality. For example, the Sahel droughts of the 1970s killed livestock, ruined successive harvests and starved some 100,000 people — a classic famine; a rise in vegetable prices is mere supply fluctuation, not famine. In answers, define the phenomenon first, then analyse causes — the layering examiners expect.
- Step 3: Natural causes — drought and desertificationNatural shocks are the immediate trigger: abnormal rains ruin crops and wither pasture; desertification steadily drains the land's productivity; pests and extreme weather destroy what remains. The Sahel sits in a semi-arid belt with a fragile ecology, so even a small rainfall failure can spark a food crisis. For example, from 1968 to 1973 the rains failed year after year, lakes and wells dried, herds died en masse, and people starved before aid arrived — showing how fast the supply side collapses when natural disaster meets a fragile ecosystem.
- Step 4: Human causes — poverty, war and unequal accessEven when food exists in markets, the poor may not afford it — this is unequal access: famine is often not a simple supply collapse but a failure of distribution and purchasing power. Poverty strips families of reserves and buying power; war wrecks farming, blocks transport and scatters people; population growth pushes demand beyond local carrying capacity; weak infrastructure keeps relief from arriving. For example, in war zones with roads closed, aid convoys cannot enter, and communities starve even though world food is plentiful; researchers have repeatedly found food still on sale in local markets during famines — proof that access and supply must be analysed separately.
- Step 5: The farming system and its factorsSeeing farming as a system organises the causes: inputs — labour, land, seeds, water, fertiliser — pass through cultivation and herding to outputs of food and livestock products; the factors shaping the system divide into natural (climate, soils, vegetation, relief) and human (economic capacity, social institutions, political conditions, technology). For example, in the same dry zone, farmers with capital to sink wells and the skill to drip-irrigate obtain entirely different output. The curriculum specifically asks you to compare how these factors combine in different places to make agricultural features diverge sharply under similar natural environments — the theme of the next case.
- Step 6: Case — nomadic herding in the SahelThe Sahel is the semi-arid belt along the Sahara's southern edge, crossing countries from Senegal to Sudan, with about 200–600 mm of rain a year that swings between years, thin soils and sparse vegetation. People live by nomadic herding and subsistence farming: herders move cattle, sheep and camels with the pasture, livestock serving as both livelihood and store of wealth. For example, herders move north to the short-grass steppes in the wet season and south in the dry — a migration that is wisdom adapted to drought; but population growth and fixed wells concentrate herds, overgrazing degrades the grassland, desertification spreads, the system's buffers shrink, and a single drought can tip it into famine.
- Step 7: Case — irrigated farming in Southern CaliforniaSouthern California is just as dry — some areas receive rain comparable to the Sahel — yet its agriculture looks entirely different: vast conveyance and irrigation works deliver water to fields, joined by fertilisers, machinery and research extension, and by big-city markets and sophisticated marketing chains, turning dry land into high-output vegetable, fruit and nut country. For example, California has long ranked first in US farm output — built on capital, technology and institutions, not rainfall. The contrast is forceful: similar natural environments, utterly different agricultural fates; relative to natural factors, human factors — especially technology — matter more and more.
4Diagrams Diagrams
5Worked example Example
Data-response practice: comparing two agricultures — Sahel: on the southern edge of the Sahara, 200–600 mm rain a year swinging widely; nomadic herding and subsistence farming, livestock the main asset; the droughts of the 1970s withered pastures, killed herds and starved hundreds of thousands. Southern California: equally dry with scant rain; irrigated farming backed by government and corporate investment in water conveyance, agricultural research and vast urban markets — a leading US producer of fruit and vegetables. Explain why agricultural features differ so greatly despite similar natural environments.
- Read the question: explain why agricultural features diverge despite similar natural environments — first note the similarity of natural conditions, then analyse each place's human factors, and conclude
- State the similar natural conditions: both are arid or semi-arid with scant rain; on natural factors alone, the two should have similar prospects
- Analyse the Sahel: low capital and technology, production hostage to rainfall; population growth drives overgrazing and overcultivation, accelerating desertification; poverty and weak infrastructure turn drought quickly into famine
- Analyse Southern California: government and business investment in water conveyance and irrigation, research extension of new varieties and water-saving technology, mature markets and marketing — human inputs overcome aridity
- Conclude: natural factors set the range of what is possible; human factors determine what is actually achieved — differences in technology and capital are the root of the divergence
- Answer: The Sahel and Southern California are both dry, with rain too scarce for high-output farming, so their natural prospects should be similar; the gulf between them lies in human factors. The Sahel relies on nomadic and subsistence farming with minimal capital and technology, production hostage to rainfall; population growth has pushed livestock and cultivation beyond the land's carrying capacity, overgrazing and overcultivation accelerate desertification, ecological buffers are thin, and drought collapses supply; poverty and weak infrastructure then block access and relief, ending in famine. Southern California built large conveyance and irrigation works with massive capital, improved varieties and water-saving techniques through research, and added mature markets and marketing chains, turning dry land into a high-output farm belt. Natural factors set the range; human factors, especially technology, determine the height actually reached — echoing the curriculum's point that human influence on agriculture keeps growing.
6Common mistakes Mistakes
7Quick check Quick check
Q1What is famine?
Q2Which four aspects does the curriculum link famine causes to?
Q3Where is the Sahel, and what farming takes place there?
Q4Why is Southern California, equally dry, such a productive farm region?
Q5Calculation: daily food supply per person is 2,200 kcal against a recommended 2,500. What percentage of the recommendation is the shortfall?
8Recap Recap
- The world grows enough food; the problems are uneven supply and unequal access
- Famine = short supply + blocked access; causes link to economy, technology, society and environment
- Natural causes: drought, desertification, pests; human causes: poverty, war, population growth, low-tech farming
- Sahel: herding + drought + desertification into famine; Southern California: irrigation + capital + technology into high output
- Similar environments, very different agricultures — human factors, especially technology, matter more and more