However, that is going to take time to build. Some people living in high-rise buildings may feel too lazy to walk downstairs to throw their rubbish and find it easier to hurl it over the balcony.

What should I do with my rubbish? Rubbish. Eurgh. It's not very nice. Usually it's smelly and sticky and can be dangerous too. No wonder we throw it away. But have you ever thought about what ...