Cattle have been getting a bad rap as environmentally unfriendly sources of climate-changing greenhouse gases. They belch methane, which is shorter-lived than carbon dioxide but more potent in warming the atmosphere. These facts have advocates urging the public to eat less beef.  But animal-sourced food also plays a vital role in global nutrition. In this Unfold episode, we look more closely at cattle’s environmental hoofprint and look at how UC Davis scientists are researching ways to make livestock more sustainable.