The production of animal protein is producing vast amounts of climate-eating gases. But a new generation of companies are creating innovative food products that mimic meat and have much smaller environmental impacts. Some of this mock meat is derived from plants with ingredients designed to replicate the taste and pleasure of chomping into a beef hamburger. Others are growing meat cells that come from a laboratory and not a cow. Bill Gates, Cargill, Tyson and other big name investors are dabbling in so-called clean meat. Emerging technologies are already offering people new food choices at restaurants and grocery stores. If these options wean enough people off burgers and chicken, will they go mainstream? Will that transition help reduce carbon pollution that is destabilizing the climate?