Dunkin' Donuts Korea handed out reusable coffee sticks to their customers. These reusable coffee sticks resemble the world's famous buildings or monuments. When the stick is dipped inside the cup, it looks as though the building is sinking under water. Therefore it is called 'Global Warming Stick'.

The 'Global Warming Stick' campaign has led customers to form a more positive attitude toward Dunkin' Donuts in Korea and consequently, has decreased the usage of disposable coffee sticks considerably.