A very interesting programme on the BBC Natural World series - A farm for the future. See it online for a limited period.

In it, Rebecca Hosking returns to her family's wildlife-friendly farm in Devon, to become the next generation to farm the land. But realising that all food production in the UK is completely dependent on abundant cheap fossil fuel, particularly oil, she sets out to discover just how we'll cope when oil becomes scarcer and more expensive; too expensive for us to continue as we are.

There's an eye-opening section 7:20 minutes in where she talks us through the oil used to produce a cheap sandwich. This includes every step of production, including preparing the land, sowing seeds, feeding (fertilisers derived from oil) and protecting the crops (herbicides, fungicides, pesticides derived from oil), harvesting, transport, baking the bread, more transport, feeding the pigs, more transport, processing into a sandwich, making the packaging (plastics derived from oil) and more transport.

The programme also suggests how we will have to adapt, with potentially huge consequences for the way we live and eat.