A new global analysis of greenhouse-gas emissions from food systems says that such emissions have been systematically underestimated—and points to major opportunities to cut them. The authors estimate that activities connected to food production and consumption produced the equivalent of 16 billion metric tons of carbon dioxide in 2018—one third of the human-produced total, and an 8 percent increase since 1990. A companion policy paper highlights the need to integrate research with efforts to reduce emissions. The papers, developed jointly by the UN Food and Agriculture Organization, NASA, New York University and experts at Columbia University, are part of a special issue of Environmental Research Letters on sustainable food systems.