In the face sagging beef sales, a slew of U.S. beef industry stakeholders have formed the U.S. Roundtable for Sustainable Beef (USRSB) to figure out how to source beef that’s, well, more “sustainable.” And although the USRSB’s intentions might be good, Americans can’t have their steak and eat it, too. That’s because the vast amount of resources it takes to produce enough beef for the country …