Build the livestock energy-use CO2 footprint extension (meat only).

Aggregate GLEAM 3.0 on-farm (direct) and feed-production (embedded) energy use into a footprint extension keyed by (year, area_code, item_cbs_code), expressed in kilograms of carbon-dioxide equivalent (CO2e). This is the energy slice of the livestock greenhouse-gas basket and is designed to be summed with build_livestock_ghg_extension() (enteric and manure CH4/N2O), which keys on the same live-animal sectors.

The GLEAM energy emission factors are expressed per kilogram of live weight (see gleam_energy_use_ef), which is well defined for meat but not for milk or eggs, so the extension covers meat only: bovine (item_cbs_code 961 non-dairy cattle and 946 buffalo), sheep (976) and goat (1016), pig (1049 and 1051) and broiler-chicken (1053) meat. Milk and eggs keep their CH4/N2O but get no energy CO2.

For each meat group the live weight produced is recovered from FAOSTAT carcass production divided by a GLEAM dressing fraction (gleam_dressing_percentages), multiplied by a per-country energy intensity (embedded + direct), and then attributed to the contributing live-animal sectors in proportion to their slaughtered head counts. Because GLEAM reports its factors by production system and climate zone but the package has no country-level system or climate shares, the intensities are collapsed to one value per country by an unweighted mean across systems and climate zones; this choice is recorded in method_energy.

Usage

build_energy_co2_extension(method = c("gleam"), data = list(), example = FALSE)

Arguments

method

Estimation method. Only "gleam" (default), the GLEAM 3.0 per-live-weight factors, is currently available.

data

Optional named list of pre-loaded inputs to avoid remote reads: primary_prod (the get_primary_production() output). It falls back to its reader when absent.

example

If TRUE, return a small fixture instead of reading remote data. Defaults to FALSE.

Value

A tibble with columns year, area_code, item_cbs_code, impact_u (energy-use emissions in kilograms CO2e) and method_energy (e.g. "GLEAM_3.0_energy_meat").

Examples

build_energy_co2_extension(example = TRUE)
#> # A tibble: 8 × 5
#>    year area_code item_cbs_code    impact_u method_energy        
#>   <int>     <int>         <int>       <dbl> <chr>                
#> 1  2010        21           961  1766900000 GLEAM_3.0_energy_meat
#> 2  2010        21          1053  3407700000 GLEAM_3.0_energy_meat
#> 3  2010       231           961  8328900000 GLEAM_3.0_energy_meat
#> 4  2010       231           976    57395000 GLEAM_3.0_energy_meat
#> 5  2010       231          1016    17517000 GLEAM_3.0_energy_meat
#> 6  2010       231          1049  1928100000 GLEAM_3.0_energy_meat
#> 7  2010       231          1051   214230000 GLEAM_3.0_energy_meat
#> 8  2010       231          1053 11171000000 GLEAM_3.0_energy_meat