Do sky lanterns damage the environment?

Partly.

It is stated that sky lanterns are fully biodegradable. The rice paper biodegrades within "6 to 8 weeks" and flourished wire takes 9 months to break down.

But this is just what manufacturers claim and it's not facts proved to society.

Anyway, if it is true we should think about the harm the wire could make to animals or even people before it rusts away. Plus lanterns cause a fire when it lands alight on moorlands, woods or even somebody's house.