More than a third of the food produced worldwide is wasted, equal to 1.6 billion tons a year. An alarming fact especially if taking into account that food waste also involves a waste of water, land and fertilisers, as well as the increase in greenhouse gas emissions. One solution to the problem is anaerobic digestion.  If food waste were used as biomass, cities could use it to generate clean and renewable energy, as well as to improve their waste management system.  The report published by the WBA and the C40 programme titled “Global Food Waste Management – An Implementation Guide for Cities” provides a global vision of the phenomenon, a collection of best practices in different cities around the world, as well as an implementation guide.