At least three U.S. coal shipments on their way to China may end up casualties of the escalating trade dispute after Beijing said it would impose steep tariffs that may kick in before the ships reach their destinations.

Few people consider used plastic to be a valuable global commodity. Yet China has imported 106 million tons of old bags, bottles, wrappers and containers worth $57.6bn since 1992, the first year it disclosed data. So when the country announced last year that it finally had enough of everybody else's junk, governments the world over knew they had a problem. They just didn’t know exactly how large it was.

What do supply chains have in common with humans? They both need occasional health checks.

Dell is tracking where its products end up after they are collected — via the company’s U.S. consumer takeback program.

Mark Gath’s farmhouse in Luverne, Minnesota, sits 30 miles down country roads from Sioux Falls, South Dakota. From that base in the heartland, Gath, a sturdy man in boots and a blue shirt, farms more than 10,000 acres of corn and soybeans with the help of his wife, Leah, and sons Dalton and Stetson. Though his farm is larger than average, he feels squeezed by low commodity prices and the rising costs of seeds, pesticides and equipment. “Everyone is scared out here,” he says.