Crops growing on fertile fields across the globe often end up on our supermarket shelves, our plates, or in animal troughs. But it’s rare that an entire plant is used to produce the food we eat. Instead, leaves, stems and shells are discarded and left behind to rot, a process which produces significant amounts of a serious environmental pollutant: methane gas. But plant scraps don’t have to be a threat: they carry great potential, too. This week, we take a look at how crop waste can be used to produce heat and electricity, all while drastically reducing greenhouse gas emissions.