What seaweed and cow burps have to do with climate change

Scientists have long known that cows are a huge source of the greenhouse gas methane, contributing up to four percent of emissions globally. But could there be a way to make cattle less -- ahem -- gassy? Animal scientist Ermias Kebreab talks through an ingenious solution to reduce methane-rich cow burps by feeding cattle something growing below the surface of the ocean: seaweed.