ABSTRACT
Climate change, for which the green house gases (GHGs) are primarily responsible, refers to the continually evolving global temperature and precipitation patterns. Carbon dioxide, methane, and nitrous oxide with differing potential to induce global warming are the three common GHGs from different natural and artificial sources. A notable percentage of atmospheric greenhouse gases is contributed by agriculture and livestock production, among anthropogenic sources. The livestock sector accounts for 58% of the GHG emissions from the agriculture and allied sectors. While ruminants makeup the bulk of GHG emissions, non-ruminants like pigs, chickens, etc., contribute to a minor amount. Approximately 18% of total global GHG emissions and 37% of anthropogenic methane gas are derived globally from ruminant processing systems. Meat and milk production account for 35 and 30% of GHG emissions from the livestock 22sector, respectively. During ruminant stomach fermentation, methane is released through a multistep process with considerable global warming potential. One of the exciting developments that can significantly reduce GHG emissions is microbial modulation. Several approaches ranging from dietary manipulation to sophisticated genetic biotechnological techniques, have been attempted to manipulate the microbial environment, to reduce GHG emissions, mainly methane. Sustainable practices to mitigate methane in ruminants are felt to be the most necessary without affecting production. To minimize GHG emission, ionophores, organic acids, and oils are part of food manipulation. Tannins and saponins also help to reduce the emissions of ruminant-stomach methane. However, each intervention has one or more pitfalls, and any single process cannot give a simple, lasting remedy. This chapter aims to address GHG emissions, mainly methane, from agriculture and allied industries, and possible mitigation measures to facilitate sustainable production with minimal environmental impact.
