### Agricultural demand

#### Indicators:

Daily caloric demand of agricultural products Animal products demand F ood crops demand | G rass and fodder species demand B iofuel crops demand Wood products demand

The Agriculture Economy Model (AEM) computes the agricultural demand for:

- 'basic' food products (i.e. the sum of temperate cereals, rice, maize, tropical cereals, pulses, and root and tuber crops)
- 'affluent' food products (i.e. the sum of beef, milk products, pork, poultry and eggs, mutton and goat meat, and oilcrops)
- food crops used as animal feed
- pasture and fodder species
- timber products

The demand for biofuel crops, i.e. crops deliberately grown for energy production, is not an output of the AEM, but is based on the demand for biofuel energy, which stems from the energy model TIMER.

The categories of 'basic' and 'affluent' products are disaggregated into the individual food products on the basis of scenarios. This disaggregation is needed for the other models of the terrestrial environment system.

For the historical period 1970-1995 the data have been used from the Food and Agriculture Organization of the United Nations on the per capita caloric intake of agricultural products, and the total regional consumption of animal products, food crops, grass and fodder species, and biofuel crops.

In all cases the agricultural demands are satisfied after one or more iterations between the AEM and the land-cover model (LCM). After these iterations, demand always equals consumption (or intake).

In general, total regional consumption of the products listed above is equal to the total regional production minus net trade.

| #### Daily caloric demand of agricultural products |
| unit: Kcal/cap (Kilocalories per capita) dimension: region, food category |

Caloric demand of agricultural products represents the per capita actual demand (or consumption) of two aggregated agricultural products:

- food crops (i.e., the sum of temperate cereals, tropical cereals, rice, roots and tubers, maize, pulses and oilcrops)
- animal products (i.e., the sum beef, milk, pork, poultry and eggs, and mutton and goat meat)

This grouping is slightly different from the aggregates 'basic products' and 'affluent products' in the sense that oilcrops are considered as part of the aggregate 'affluent'. The reason is that the Agricultural Economy Model better allows simulating the ratio between these aggregates than between food crops and animal products.

Caloric demand refers to the human consumption, and excludes the use of agricultural products as animal feed and other uses.

The consumption of animal products has large indirect land requirements for the production of grass and fodder species and crops used as feed. Therefore, a shift in the demand towards more affluent products (and thus animal products) will indirectly cause an increasing demand for land, even if the total caloric intake per capita of basic and affluent products remains stable.

| #### Animal products demand |
| unit: 1000 Gg/yr (teragram fresh weight per year) dimension: region, animal product, type of use |

The animal products demand is defined as the total regional demand (or consumption) for each of the animal products (i.e. beef, milk, pork, poultry and eggs, mutton and goat meat), and for different types of use:

- human consumption, based on scenario-driven fractions for each of the 7 animal products included in affluent products
- use as animal feed (mainly milk), based on fixed fractions per region (see also animal husbandry)
- other 'uses', primarily production losses in the food processing industry and losses during transport
- stock change, based on historical data for the period 1970-1995. Stock changes are assumed to decrease to zero in future scenarios

Fixed region-specific caloric values of the animal products are used to convert caloric intake to fresh weight (for milk) or carcass fresh weight (for meat, excluding bones and intestines).

The total regional consumption of animal products is equal to the regional production minus net trade (i.e. export minus import).

It should be noted that the demand demand for 'affluent products', primarily animal products, is calculated by the agricultural economy model. However, the results for some individual products included in the affluent products group are also determined by the scenario assumptions on caloric intake. For South Asia this leads to a low fraction of beef and a high fraction poultry and pork. For North Africa and the Middle East this leads to a low fraction of pork.

| #### Food crops demand
| unit: 1000 Gg/yr (teragram fresh weight per year) dimension: region, aggregated food crop, type of use

The food crops demand represents the total regional demand (or consumption) for each of the seven food crops (i.e. temperate cereals, rice, maize, tropical cereals, pulses, root and tuber crops, and oil crops), and for other uses and stock changes as summarized below:

- human consumption, based on scenario-driven fractions of total intake of food crops for each individual food product (i.e. all food crops excluding oil crops). The use of oil crops (included in affluent products) is based on the corresponding scenario-driven fraction of total intake of food crops. To avoid unrealistic consumption patterns, the maximum value for this fraction is the 1995 level of OECD Europe
- animal feed use, based on fixed fractions per region (see also animal husbandry)
- other uses, primarily production losses in the food processing industry and losses due to transport, and applications in non-food industrial sectors (for example, lubricants, cosmetics, paints, etc)
- stock change, which is based on historical data for the period 1970-1995. Stock changes are assumed to decrease to zero in future scenarios

Fixed region-specific caloric values of the food crops are used to convert caloric intake to fresh weight.

The total regional consumption of food crops is equal to the regional production minus net trade (i.e. export minus import).

It should be noted that the demand for food crops is calculated by the agricultural economy model. However, the results for the intake of oilcrops are also determined by the scenario assumptions on caloric intake.

| #### Pasture and fodder species demand |
| unit: 1000 Gg/yr (teragram dry weight per year) dimension: region

The pasture and fodder species demand is defined as the total regional demand (or consumption) of pasture and fodder species. Pasture and fodder species demand is related to the number of grazing animals (cattle, sheep and goats), the feed efficiency and the composition of the feed (i.e., the importance of crops relative to grass and fodder). The demand for animal feed (including pasture and fodder species) is derived from the production of animal products as described in more detail in animal husbandry.

Because no trade in pasture and fodder species is assumed, consumption equals production in all world regions.

| #### Wood products demand
| unit: 1000 m3/yr (1000 cubic metres per year) dimension: region, wood product

The wood products demand represents the total regional demand of wood products, divided into three categories:

- pulpwood and particles
- sawlogs, veneer and other industrial roundwood
- fuelwood and charcoal

The demand for fuelwood and charcoal is assumed to be a fixed fraction of the demand for traditional biofuels as computed by the energy model (TIMER). The prduction of other wood products is computed with a statistical relationship between timber production, population growth, industrial value added (IVA), and the remaining forest areas. This regression was based on historical data from theFood and Agriculture Organization of the United Nations. The wood volumes are converted to weights on the basis of conversion factors of the Food and Agriculture Organization of the United Nations. The treatment of forests after wood extraction is described in the land-cover model.

| #### Biofuel crops demand
| unit: 1000 Gg/yr (teragram per year) dimension: region, biofuel crop

The biofuel crops demand represents the total regional demand (or consumption) of modern biofuel crops (i.e. sugar cane, maize, woody biofuel crops, and non-woody biofuel crops). It is expressed in teragram fresh weight per year for sugar and maize, but in dry weight for woody and non-woody biofuel crops. The consumption of biofuel crops is based on the demand for energy provided by biofuels as computed by the energy model (TIMER), the energy content of each crop to convert to crop weight, and the crop yield. The TIMER model also simulates net trade of biofuels. As it is assumed that there is only trade in processed fuels, for each region the consumption of biofuel crops equals its production. The regional production of traditional biofuels (e.g. fuelwood and charcoal) is scenario-driven (i.e. exogenous) and can be found in production of wood products.