When you throw away rubbish, it can create an environmental problem - or a business opportunity.

Your old newspapers, tin cans and plastic bottles are someone else's valuable harvest. Just like gold, steel, sugar or coffee, rubbish is traded all over the world as a commodity. If it can be recycled, it's worth money.

Until recently, countries vied to recycle the waste of others. But now one of the main players - China - says it doesn't want foreign rubbish anymore. That has sent this multi-billion dollar industry into turmoil and is forcing it to invent new solutions. Ruth Alexander reports.

Producer: Tony Bonsignore. Show less