Estimation and mitigation of GHG emissions from ruminant livestock in Pakistan

Abstract

The study examined baseline emissions of greenhouse gases from ruminant livestock in Pakistan for the year 2014 and evaluated feasible interventions for mitigating the sector emissions. Total emissions (as CO2-equivalents) from livestock supply chain from cradle to farm gate were estimated at 431007 × 103 t. Major part (77%) of the emissions was produced by the mixed system and the remaining 23% was contributed by the grazing system. Methane emissions were 62.5% of the total emissions, followed by N2O at 29.4% and CO2 at 8.1%. Bulk of milk (87.6%) and meat (59.4%) was produced by the mixed system, which was associated with three-fold higher emissions at 332248 × 103 t than when they were produced by the grazing system. The emission intensity (kg CO2-eq/kg protein) of milk and meat averaged 183.4 and 443.2 respectively, and ranked higher than the global average values. Buffaloes were responsible for the major proportion of emissions, followed by cattle. Average emissions per animal in buffalo, cattle, sheep and goat were 4.27, 3.27, 0.28 and 0.25 t CO2-eq/year respectively. The emission intensities (kg CO2-eq/kg commodity protein) of both milk and meat remained lower in cattle than buffalo and were calculated as 166.1 and 299.7 in cattle and 189.5 and 527.9 in buffaloes respectively. The carbon footprint of milk and meat in sheep and goats also remained high and averaged 189.0 and 472.6 kg CO2-eq/kg protein respectively. Overall, the emission intensity of meat was slightly higher in the grazing system than mixed system, but remained much higher in non-dairy herds than in dairy herds (1006.6 vs 46.6 kg CO2-eq/kg meat protein). Interventions such as improving diet quality through increased fodder supply, vaccination for adequate health control and genetic improvement reduced emission intensities of milk (kg CO2-eq/kg protein), varying from 20.3% to 36.8% compared with the baseline in dairy cows and buffaloes and this was associated with a positive productivity outcome of enhanced milk production by 25–50%. More significant reduction in emission intensities of milk between 48.1% and 53.1%, together with a 100% increase in milk yield above baseline, resulted from combined application of the three interventions as a single package.