Agriculture and land use change are responsible for one third of global greenhouse gas (GHG) emissions. These emissions have risen steadily during the 20(th) century and pressures to increase food production to support growing human populations threaten to increase emissions still further, as climate change induced by the accumulation of GHGs threatens the sustainability of agricultural production. There are, however, opportunities to mitigate emissions through modifications to agricultural management that involve more efficient use of inputs and promotion of carbon sequestration. Management activities need to be adapted to take account of the variability in climates and soils, and patterns of emissions. There also need to be improvements to current methods of compiling inventories of GHG emissions to ensure that they accurately reflect actual emissions and management changes.