The idea came to Uma Valeti while he was working on regrowing human tissue to help heart attack patients: If we can grow tissue from cells in a lab, why not use animal cells to grow meat? Food production accounts for as much as a third of the world's greenhouse gas emissions. The idea behind cultivated meat is to help feed the world while dramatically reducing human contributions to global warming and avoiding killing animals. NPR Health Correspondent Allison Aubrey has been visiting production facilities and talking with both food and climate scientists to understand how far away lab-grown meat is from store shelves, and what a meal of cultivated chicken tastes like.We'd love to hear your thoughts on our show. Take our survey: npr.org/shortwavesurvey Reach the show by emailing shortwave@npr.org.