Agriculture produces ∼10%–12% of total global anthropogenic greenhouse gas emissions,
contributing ∼50% and ∼60% of all anthropogenic methane (CH4) and nitrous oxide (N2O),
respectively. Apart from their significant contribution to anthropogenic greenhouse gas
emissions, the energy lost as CH4 and total N losses are two of the most significant inefficiencies
remaining in ruminant production systems. A number of options are reviewed to reduce
production of enteric CH4 and N2O from ruminant production systems, mainly focusing on
breeding, feeding, animal management, soil and fertilizer management, and rumen
manipulation. To fully assess the net abatement potential, each strategy must be subjected
to whole-farm systems modelling and a full life-cycle assessment, to ensure that a reduction in
emissions at one point does not stimulate higher emissions elsewhere in the production
system. Most of the options reviewed require many years of research before practical strategies
and commercially viable products are available for use on farms. This paper reviews the options
available for livestock production to reduce CH4 and N2O emissions while improving
production, and highlights research issues and the need for a systems approach to the
evaluation of the relative merits of abatement options