Supertankers are carrying 3.8 billion barrels of crude oil among them, enough to fuel around 418,000 transatlantic flights and for the world’s cars to cover around 3 billion miles between them. Their sticky cargo is the raw material for billions of plastic bags, combs, trainers, drinking straws, synthetic clothing, toys, water bottles and hundreds of other plastic-based goods that we use in our daily lives. But can they be transformed to be good for the environment?