In this episode, Kate is joined by Dan Egan, author of the Devil’s Element: Phosphorous and a World Out of Balance. Why  phosphorus?  Phosphorus is vital for life on Earth and plays a pivotal role in fertilizers that sustain agriculture. However, it’s also a finite resource where its overuse in fertilizers has led to significant environmental concerns such as toxic algae blooms. The history of phosphorus, from its isolation as an element, to its sordid history and its various applications, including warfare, is explored. Somehow, phosphorous is at the heart of our food system, the conception of the soap opera, the Clean Water Act,  and the children’s rhyme “Shelly sells seashells by the seashore.” Its history is nothing short of sordid and it is “the gravest natural resource shortage you’ve never heard of.” Dan and Kate also explore future sources of phosphorous and whether or not waste is really waste at all. This is an essential part of understanding agricultural systems and a great interview.