5 percent of American 's leftovers can feed 4 million people for 1 day . Disposing of food waste costs the government $ 1 billion a year . AD is a process where organic matter -- such as food waste -- breaks down in an environment with little or no oxygen , generating a natural gas made up of 60 percent methane and 40 percent CO2 . Rotting food releases CO₂ , a more potent greenhouse gas than CO2 . This can be harnessed to produce clean energy for heat , light and fuel .
5 percent of American 's leftovers can feed 4 million people for 1 day . Disposing of food waste costs the government $ 1 billion a year . Rotting food releases CO₂ , a more potent greenhouse gas than CO2 . This can be harnessed to produce clean energy for heat , light and fuel .