Comparative Assessment of Greenhouse Gas Emissions in Pig Farming Using Tier Inventories

Abstract

Although pig meat accounts for nearly half of total meat production in Europe, less attention has been focused on the greenhouse gas (GHG) emissions of pig farming. The aim of this study was to assess and compare the impact of pig livestock on GHG emissions during the period 2015–2020 in major European countries, including Greece, using different computational approaches (Tier 1, Tier 2, Gleam-i software v. 2.0 developed by FAO, Rome, Italy). A semi-extensive pig farm was also used as a small-scale scenario. The ranking of the countries related to GHG emissions was not affected by the applied methodology. Spain had the highest emissions due to the higher number of farming animals. The noted numeric differences in the estimations can be attributed to the elaborated and different equational approach that Tier 2 methodology and Gleam-i followed, considering many livestock parameters. Additionally, the semi-extensive farm had lower emissions/fewer animal compared to the average intensive pig farm in the Greek territory. The Tier 1 approach revealed that breeding animals produces more to the emissions, contrary to Tier 2, which showed that fattening pigs is responsible for the majority of GHG emissions. Therefore, specific animal categories could be targeted (i.e., fattening gilts) in a more specialized manner apart from general strategies (i.e., animal improvement).