There's a dirty secret around the back of your fridge. The world's freezers, fridges and air conditioning units are chilled by gases that have planet-warming properties that are hundreds or even thousands of times more powerful than carbon dioxide. Disposed of properly they're not a problem but in much of the developing world these gases- legal ones and even more dangerous illegal gases- are simply vented to the atmosphere when the cooling units are dumped or recycled. In the first of ten more programmes highlighting the world's best carbon-busting ideas, Tom Heap meets the fridge detectives hunting the planet for the worst offenders and safely disposing of their deadly gases. Dr Tamsin Edwards of King's College, London, armed with statistics gathered by the Royal Geographical Society, joins Tom to add up the numbers and calculate the carbon impact of the fridge detectives. Producer: Anne-Marie Bullock Researcher: Sarah Goodman Produced in conjunction with the Royal Geographical Society. Particular thanks for this episode to Dr Luke Western and Dr Daniel Say of the University of Bristol and to Professor John Pyle of the University of Cambridge.