Build a grazing-land footprint by forward feed-allocation.

End-to-end grazing-land footprint for one year on real WHEP data. Grazing land (the grassland extension) is pushed forward onto livestock meat and milk via allocate_grazing_to_products(), then routed to consuming countries through the bilateral meat-trade network with compute_footprint_balance(). This attributes grazing land to the meat and dairy consumption that drives it – the chain the Leontief footprint leaks because grass is non-productive and not traded.

The inputs are assembled from build_grassland_land_extension(), get_feed_intake(), get_primary_production() and get_bilateral_trade(). Supply any of them through data to reuse cached inputs or to test without remote reads.

intake_basis selects the intake that splits grazing land across animals. The default "grazer_forage" uses every grazing animal's grass plus roughage-residue intake, because the feed model classes the forage of major extensive-grazing countries (for example Australia, the United States and Argentina) as residues rather than grass; keying on the "grass" feed type alone would silently strip that land. "grass" reproduces the narrower grass-feed basis for sensitivity analysis. Land in countries with no grazer intake at all cannot be attributed and is reported via a warning.

Usage

build_grazing_feed_footprint(
  year,
  products = c("all", "meat_milk"),
  intake_basis = c("grazer_forage", "grass"),
  data = list(),
  example = FALSE
)

Arguments

year

Year to build the footprint for.

products

Co-product split passed to allocate_grazing_to_products(). "all" (default) or "meat_milk".

intake_basis

Intake used to split land across animals, "grazer_forage" (default) or "grass".

data

Optional named list of pre-built inputs, any of grass_land, grazer_intake, livestock_production and trade. Each falls back to its builder when absent.

example

If TRUE, return a small example output without downloading remote data. Default is FALSE.

Value

A tibble with area_code (consuming country), item_cbs_code (meat or milk item), value (embodied grazing land) and method ("grazing_feed_allocation").

Examples

build_grazing_feed_footprint(example = TRUE)
#> # A tibble: 10 × 4
#>    area_code item_cbs_code     value method                 
#>        <int>         <int>     <dbl> <chr>                  
#>  1        10          2848 184625300 grazing_feed_allocation
#>  2        10          2731  71204900 grazing_feed_allocation
#>  3        41          2731  38950100 grazing_feed_allocation
#>  4        33          2848  24310700 grazing_feed_allocation
#>  5        33          2732   9875400 grazing_feed_allocation
#>  6       100          2731   6420300 grazing_feed_allocation
#>  7        79          2848   3155800 grazing_feed_allocation
#>  8       179          2735    812600 grazing_feed_allocation
#>  9       122          2740     49120 grazing_feed_allocation
#> 10       137          2732     18430 grazing_feed_allocation