The Global Information and Early Warning System on food and agriculture at the FAO. It watches harvests and food prices country by country and issues alerts.The system matters because food crises rarely appear overnight; they build over months as crops fail, prices rise, and people run out of ways to cope. By providing timely, objective information, GIEWS helps shift the global response from reactive emergency aid to proactive prevention. Its reports are used by humanitarian organizations to decide where to send food, by governments to plan import needs, and by researchers to understand how climate and conflict affect food systems. The system also monitors the food security situation in countries that are not in crisis, providing a baseline that makes it easier to spot anomalies.
GIEWS was established in 1975 by the FAO in the aftermath of the world food crisis of the early 1970s, when a combination of bad harvests and oil price shocks caused global food prices to spike and exposed the lack of reliable early warning information. It has operated continuously since then, adapting its methods as satellite technology and data processing improved.
GIEWS combines satellite imagery of vegetation health with ground reports from FAO field offices, national agricultural ministries, and local partners. Satellite data, such as the Normalized Difference Vegetation Index (NDVI), shows how green and vigorous crops are compared to historical averages, which reveals drought stress early. These remote observations are cross-checked with on-the-ground assessments of planting area, crop conditions, and market prices. The system also runs crop models that simulate how weather and soil conditions translate into yields. All this information is synthesized into regular reports, including the 'Crop Prospects and Food Situation' quarterly and the 'Food Price Monitor', and into special alerts when conditions deteriorate sharply.
GIEWS is used by the World Food Programme, national governments, and NGOs to trigger emergency food assistance, by analysts to forecast global grain prices, and by researchers studying the links between climate extremes and food insecurity.
GIEWS monitors food prices in over 1,000 markets worldwide, and its price data has been used to show that the 2007-2008 global food crisis was driven more by export bans and panic buying than by actual crop shortfalls.

