This 2016 paper in Environmental Science and Technology notes that in the year 2010, food availability was 20% higher than was required on a global scale, and provides a systematic approach to estimate consumer level food waste on a country scale and globally, based on food availability and requirements. It concludes that GHG emissions related to the food surplus increased from 130 Mt CO2eq/yr to 530 Mt CO2eq/yr, an increase of more than 300%. The report projects that GHG emissions associated with the food waste may increase to 1.9−2.5 Gt CO2eq/yr.