Accounting methane and nitrous oxide emissions, and carbon footprints of livestock food products in different states of India

Greenhouse gas (GHG) emissions from enteric fermentation and manure management of different Indian livestock species were estimated from the latest Indian livestock population data published in 2012 using Intergovernmental Panel on Climate Change Tier 2 (2006) guidelines, and carbon footprints (CF) of different livestock products were assessed in different states of India. Indian livestock produced 304,030, 31,045 and 3978 Gg y−1 in CO2 equivalent (CO2e) of enteric methane (CH4), manure CH4 and manure nitrous oxide (N2O), respectively in 2012. The contributions of GHG by cattle, buffalo, sheep, goat, pig and other animals were 55, 37, 4, 2, 1 and 1%, respectively. Enteric CH4 was the major source of GHG, accounting for 89.7% of total GHG emissions, followed by manure CH4 (9.2%) and N2O (1.2%). The CF values for milk, meat and eggs ranged widely among the different states of India. The average CF values of fresh milk production were considerably lower for crossbred cows (1.21 kg CO2e kg−1), followed by buffaloes (1.85 kg CO2e kg−1) and goats (2.54 kg CO2e kg−1), and were highest for indigenous cattle (2.96 kg CO2e kg−1). These trends were also observed for CF values expressed as GHG kg CO2e kg−1 milk protein. However, CF values in terms of GHG in kg CO2e MJ−1 milk energy output were similar for crossbred cattle and buffaloes (0.41 and 0.42 kg CO2e MJ−1), but were higher for goats (0.83 kg CO2e MJ−1) and indigenous cattle (1.0 kg CO2e MJ−1). The wide range of CF values for milk, meat and eggs in different states of India suggests that CF of livestock products could be reduced substantially through changes in the pattern of livestock population, adoption of improved breeding technologies or crossbreeding programs and status of intensification for different livestock species.