The production of carbon neutral fuel, biodiesel, from cooking oil, animal fat and plants. At a biodiesel refining plant in Motherwell, 35,000 tonnes of old cooking oil and animal fat is filtered each year and chemically converted into diesel fuel. The fuel is mostly mixed with normal diesel to power lorries and some cars. Biodiesel is produced from plant material and so in theory it is carbon neutral; the plants it is produced from consume the same amount of carbon dioxide as is produced when the biodiesel is burnt.

First broadcast:
6 October 2008

Challenge students to investigate how the use of biodiesel would help with the fight against global warming and how more individual drivers and companies could be encouraged to switch to using biodiesel. Also challenge students to consider the disadvantages of biodiesel production.