Estimation of CH4 emissions and global warming potential of Marmara Region small livestock sector with 2019 refinement IPCC Tier-2 method

Abstract

Livestock production is predominantly conducted in intensive farming operations, where large-scale production poses significant challenges related to waste management and environmental pollution. The Marmara Region represents a critical area in Türkiye where intensive animal feeding operations are widely practised. In contrast, goat and sheep farming in Türkiye generally rely on pasture-based or semi-intensive systems. This study aims to estimate methane (CH4) emissions from small ruminant farming in the Marmara Region over the past 20 years and to assess the resulting carbon footprint to evaluate its impact on global warming. Methane emissions were calculated using the Tier-2 methodology, incorporating the specific characteristics of the region and the general practices of small ruminant farming. Gross energy (GE) and methane emission factors (EF) were derived accordingly. For sheep, the gross energy was calculated as 22.5 MJ head-1 year-1, the methane emission factor from enteric fermentation (EFE) was 9.9 kg CH4 head-1 year-1 and methane emissions from manure management (EFM) amounted to 4.3 kg CH4 head-1year-1. Similarly, for goats, the GE was determined to be 24.6 MJ head-1 year-1, while the EFE, and EFM were, 8.9 kg CH4 head-1 year-1, and 4.4 kg CH4 head-1 year-1, respectively. The study found that CH4 emission rates increased proportionally with the number of animals. To determine the carbon footprint resulting from CH4 emissions, CO2-equivalent values established by the Intergovernmental Panel on Climate Change (IPCC) were applied. Consequently, Balıkesir and Çanakkale emerged as the cities with the largest carbon footprints from small ruminant farming within the Marmara Region.