Finally something useful from what comes out of the back end of a pig.
Anaerobic digestion – a process where microorganisms break down organic material
in the absence of any oxygen to produce a methane and carbon dioxide-rich biogas.
This can be burnt to produce energy, with none of the harmful effects of fossil
fuels. And what's more, the nutrient-rich solids left after digestion can be
handily used as a fertiliser!