conserve

conserve is a way to protect the environment from harm or danger


Source
https://www.618tacc.amc.af.mil/News/?Page=12

recycle

recycle is a way of turning waste materials into something new. It is used to help protect the environment.  


Source
https://www.dover.af.mil/News/Article-Display/Article/229892/reusing-with-imagination-children-learn-about-recycling/