It is estimated that one-third of all food produced in the world each year for human consumption never reaches the table. This leads to increased greenhouse gas (GHG) emissions from the food that is not consumed by the end-user. Food waste that enters landfills produces methane, a potent GHG, and does not allow the nutrients to be returned to the land. This fact sheet describes the primary sources of food waste, the GHG impact of food waste, mitigation opportunities including anaerobic digestion and specific opportunities and considerations for dairy farms.