The Global Centre for Risk and Innovation (GCRI)
Food systems are hit by shocks that start in different places: drought and flood, pests such as desert locust and fall armyworm, plant and animal disease, conflict, economic crises and disruption of trade or energy. The damage depends less on the shock itself than on what it meets: concentrated supply, low stocks, high import dependence, indebted households and weak services. This page sets out how food-system shocks propagate and compound, how they are monitored, and who acts on the evidence.
Fig.Market and harvest early warning. Design wireframe with placeholder names and illustrative values, not a record or a live system.
Food system shocks are sudden disruptions that start in weather, pests, disease, conflict, economic crisis or trade and reach what people can eat. The harm depends on what the shock meets: concentrated supply, low stocks, import dependence, indebted households and weak services. Early warning systems such as FEWS NET and FAO GIEWS monitor them; anticipatory action releases help before the peak.
Plains, deltas and basins, the corridors that carry food to ports, and how far each division sits from one, shown for Central America as an example geography for this subject.
Disease, drought, conflict and supply disruption. The dossier below sets out how the risk develops, what is measured, where the data come from, how it is modelled and who decides.
Drought, heat and flood reduce harvests, kill livestock and destroy stores, and they cut farm labour income at the same time. Rural households lose their food and the money to buy it in the same season.
Desert locust swarms, fall armyworm, wheat rusts, African swine fever and avian influenza spread with wind, trade and animal movement. Control depends on surveillance and rapid response in countries that may lack both.
Conflict displaces farmers, blocks markets and aid, destroys infrastructure and drives up prices. It is a leading driver of the most severe food crises and often coincides with weather and economic shocks.
A drought that coincides with a currency crisis, a fertiliser price spike and an export ban causes far more hunger than any one alone. Recovery is slow because assets sold to cope are not quickly rebuilt.
Each term as this page uses it. Where a standard-setting body defines the term, the wording follows that body.
| Term | Definition |
|---|---|
| Anticipatory action | Pre-agreed action and finance released on a forecast or early warning trigger, before a hazard's peak impact. |
| Famine | The most extreme food crisis, classified by the IPC when thresholds for food consumption, acute malnutrition and mortality are all crossed in an area. |
| Transboundary pest | A pest such as desert locust or fall armyworm that spreads across borders and needs regional monitoring and control. |
| Sendai indicator C-2 | Direct agricultural loss attributed to disasters, reported by countries under the Sendai Framework monitor. |
Each indicator carries its unit, its cadence, the kind of source behind it and the evidence label a value would carry. No values are shown: a programme supplies them under its own authority.
| Indicator | Unit | Cadence | Source type | Label |
|---|---|---|---|---|
| Seasonal rainfall anomaly | percent of the long-term mean | dekadal | Satellite and gauge rainfall | ESTIMATED |
| Agricultural stress index | percent of cropland affected by water stress | dekadal | Satellite vegetation and temperature indices | MODELLED |
| Desert locust situation level | warning level from calm to danger | weekly | FAO Desert Locust Information Service | OFFICIAL |
| Animal disease events notified | count by disease and country | weekly | Official veterinary notifications | OFFICIAL |
| Conflict events in agricultural areas | events per administrative unit | weekly | Event coding from media and partner reports | REPORTED |
| Projected population in IPC Phase 3 or above | persons | per analysis | IPC and Cadre Harmonisé projections | FORECAST |
| Direct agricultural loss from disasters (Sendai indicator C-2) | monetary value at constant prices | per event | Post-disaster needs assessments | ESTIMATED |
The topic as a computational graph: named sources feed the methods, an evidence review gates the outputs, and the decisions stay with the authorities that hold them.
Fig. 02Nodes carry their type, two metric rows and a state; connectors show what feeds what; dashed frames name the owners; the timeline is the cadence. Design of the pipeline, not a record of a run.
Named public datasets and institutional records, each with its licence class. Sources by agreement are used only under their terms and never republished.
| Source | What it gives | Licence class |
|---|---|---|
| FAO Global Information and Early Warning System (GIEWS) | Country briefs, agricultural stress index and crop prospects | Free and open, attribution |
| FAO Desert Locust Watch and Locust Hub | Locust situation bulletins, survey and control records | Free and open, attribution |
| WOAH World Animal Health Information System (WAHIS) | Official notifications of animal disease events | Public, terms per WOAH |
| ACLED | Coded conflict and protest events with location and date | Free with registration, terms per ACLED |
| EM-DAT (CRED) | Disaster events and recorded impacts by country | Free for non-commercial use, registration |
| CHIRPS rainfall | Gauge-blended satellite rainfall for drought monitoring | Public domain |
| Global Report on Food Crises | Annual synthesis of acute food insecurity and its drivers by country | Free, attribution |
Food Nexus prepares evidence. The decisions below are taken by the authorities named, under their own rules, and never by the platform.
| Who decides | The question | Evidence this page serves |
|---|---|---|
| Disaster management and agriculture ministries | When to activate contingency plans, release reserves or request assistance | Early-warning indicators agreeing across sources; projected acute food insecurity phases |
| Plant protection and veterinary services | Where to survey, treat, vaccinate or restrict movement | Pest and disease notifications, habitat conditions and animal and trade movements |
| Humanitarian agencies and anticipatory action financiers | Whether forecast triggers justify acting before the shock peaks | Trigger skill from hindcasts, lead time, and the cost of acting and of not acting |
| Sovereign risk pools and agricultural insurers | Whether a drought index pays when losses occur, and how basis risk is managed | Index performance against recorded losses by season and area |
History shows that the most severe food crises seldom have one cause. They arise when a production shock meets weak buffers, high prices and constrained public finances, often during conflict. Experts therefore study shocks as combinations and sequences, and ask how preparation and early action can break the chain before harm peaks.
Shocks compound when buffers are thin and when they strike several links at once.
Droughts, floods and heat cause the largest production losses. Climate change alters their frequency and severity. See Climate and Hazards.
Outbreaks such as locusts, wheat rusts or animal diseases can spread quickly across borders.
Conflict destroys assets and blocks access; trade restrictions and economic crises reduce supply and purchasing power.
Rainfall, vegetation, price and pest signals, analysed with forecasting and time-series analysis, give lead time. False alarms and missed events both occur.
Explores compound shocks and cascades. Scenarios are explorations, not forecasts.
Past crises show patterns of propagation and response, though conditions change.
Evaluations of pre-agreed actions taken before a shock peaks are growing but remain limited for some hazards.
The current service level is R0: information and enquiries. An enquiry receives a reference and names the next step; applications, payments, compute allocations and registrations open only when their team, terms and review capacity exist.