Please give some certain ideas or topic for making outstanding  "working / non - working" model on "Saving environment and way to the make the environment safe" . 

{Please I want an idea/topic for a science  model only}
I know that, this requires my own skills, but I want some good ideas for the respective topic for making working / non - working" model . 

These questions focus on developing your creative skills. We recommend that you frame a model on your own. However, you can refer to the following idea if you want:

You can use prepare a garden by using artificial grass and trees. At one corner you can show proper disposal system for waste (green and red bins separately) in it and a pathway where people are using cycles as means of commuting. To make your message more clear, you can put a small write up along with all these ways to save the environment. 

Regards.