Much of our biodegradable waste, from food and garden detritus to cardboard and paper, is sent to landfill. Once deposited in these sites it breaks down and releases methane, a powerful and complex gaseous compound which contributes to the greenhouse effect.
With anaerobic digestion treatment, however, this waste is composted in the absence of oxygen, producing a biogas which can then be used to generate electricity and heat. This works within the bounds of sustainability because carbon from biodegradable material is part of a carbon cycle. Released into the atmosphere by the burning of the biogas, this carbon is removed by plants which are then regrown, again removing the carbon from the air and creating a virtuous circle of ‘carbon neutrality’. This contrasts with fossil-fuels carbon, the burning of which provenly increases the concentration of CO2 in the atmosphere. Anaerobic digestion is therefore highly effective in tackling climate change, instead of compounding the problem by way of landfills and polluting incineration.