IPCC Tier 1 enteric emission factors, as published. — ipcc_enteric_ef

Tier 1 enteric fermentation emission factors (kg CH4/head/yr) as the 2019 Refinement publishes them, which the ipcc_2019_enteric_ef_* tables did not hold (whep#601). Tier 1 enteric CH4 reads this table by default; the enteric_ef_source manure-engine option selects it ("ipcc_2019") or the older tables ("as_shipped"), see manure_engine_options.

A category has one of three shapes:

regional (region is an IPCC region, productivity == "All"): dairy cattle, other cattle and buffalo, Table 10.11 (Updated). Only the Tier 1 column is carried; the high/low productivity rows the table adds for five regions are Tier 1a, which needs the head count split by productivity system. North America and Oceania publish no buffalo factor ("no buffalo herds").
split by productivity (region == "All", productivity "High" or "Low"): sheep, goats and swine, Table 10.10 (Updated). Its footnote 1 says that "for all regions other than North America, Europe and Oceania the Tier 1 default values are the low productivity EFs", so Tier 1 takes "High" in North America, Western Europe, Eastern Europe and Oceania and "Low" in every other IPCC region.
flat (region == "All", productivity == "All"): horses, camels, mules and asses, and the deer, ostrich and llama/alpaca rows of the same table.

Poultry has no row: both editions say "insufficient data for calculation". A row the edition prices at nothing – poultry, buffalo in North America or Oceania, or a regional or productivity-split species on a row whose IPCC region does not resolve – keeps the as-shipped factor, and method_enteric says so (enteric_ef_as_shipped_fallback).

Usage

ipcc_enteric_ef_tier1

Format

A tibble with one row per edition, region, category and productivity:

edition: "ipcc_2019".
region: IPCC Tier 1 region, or "All".
category: "Dairy Cattle", "Other Cattle", "Buffalo" or a general species name.
productivity: "All", "High" or "Low".
ef_kg_head_yr: emission factor, kg CH4 per head per year.
ipcc_table: the table the value was read from.

Source

IPCC. 2019. 2019 Refinement to the 2006 IPCC Guidelines for National Greenhouse Gas Inventories, Vol 4, Ch 10, Table 10.10 (Updated), p. 10.38, and Table 10.11 (Updated), pp. 10.40-10.43 (PDF md5 c1784e747af9bb307e93f4170c12679a, downloaded from ipcc-nggip.iges.or.jp and checksummed on 2026-10-07). Every value is a transcription.

Measured effect

On FAOSTAT 2020 heads at national grain, Tier 1 enteric CH4 goes from 110.8 Tg (as shipped) to 125.3 Tg: cattle 78.58 to 90.98 Tg, buffalo 11.21 to 16.55 Tg, sheep 10.30 to 7.31 Tg (low productivity outside the four high regions), swine 1.41 to 1.08 Tg and goats 5.47 to 5.56 Tg. Every row resolved an IPCC region; the only fallback rows were poultry and 163 buffalo head in North America and Oceania.

Examples

ipcc_enteric_ef_tier1
#> # A tibble: 37 × 6
#>    edition   region         category     productivity ef_kg_head_yr ipcc_table  
#>    <chr>     <chr>          <chr>        <chr>                <dbl> <chr>       
#>  1 ipcc_2019 North America  Dairy Cattle All                    138 10.11 (Upda…
#>  2 ipcc_2019 North America  Other Cattle All                     64 10.11 (Upda…
#>  3 ipcc_2019 Western Europe Dairy Cattle All                    126 10.11 (Upda…
#>  4 ipcc_2019 Western Europe Other Cattle All                     52 10.11 (Upda…
#>  5 ipcc_2019 Western Europe Buffalo      All                     78 10.11 (Upda…
#>  6 ipcc_2019 Eastern Europe Dairy Cattle All                     93 10.11 (Upda…
#>  7 ipcc_2019 Eastern Europe Other Cattle All                     58 10.11 (Upda…
#>  8 ipcc_2019 Eastern Europe Buffalo      All                     68 10.11 (Upda…
#>  9 ipcc_2019 Oceania        Dairy Cattle All                     93 10.11 (Upda…
#> 10 ipcc_2019 Oceania        Other Cattle All                     63 10.11 (Upda…
#> # ℹ 27 more rows