Chilled lorries are the backbone of our food distribution system, keeping our pork pies and hummus safe and fresh on route to the supermarket. The problem for our air quality and carbon emissions is that many of the refrigeration units are powered by diesel engines. Tom Heap meets a team converting these Transport Refrigeration Units from diesel to liquid nitrogen. If successful they could take a bite out of greenhouse gases in the west and, more importantly, offer a clean chilling option for farmers and food companies in the developing world. Food that spoils on the way to the consumer hurts farmers, causes hunger and increases carbon emissions. If meat, dairy, fruit and vegetables can be kept fresh for longer then everyone wins. Dr Tamsin Edwards of King's College, London helps Tom calculate just how much carbon dioxide could be removed from the environment if we use techniques like this to slash food waste. Producer:: Anne-Marie Bullock Series made in partnership with the Royal Geographical Society