Disclaimer: I am a moderator of /r/ZeroWaste.

I believe that /r/ZeroWaste is a great community for exploring deeper into ways of reducing your waste and your footprint on the world.

The sidebar description:

Being "zero waste" means we adopt steps towards reducing personal waste and minimizing environmental impact. The zero waste ideal is to send nothing to landfills or high-temperature incineration facilities and to prevent unnecessary pollution and the squandering of nonrenewable resources.

This community is for those who are interested in living a low- or zero-waste lifestyle. There is a major focus on the "5 R's", being refuse, reduce, reuse, recycle, and rot. We follow this by reducing consumption, choosing reusable and sustainably-produced goods, promoting recycling and composting, and encouraging each other in our attempts to live more sustainably.

It is still a smaller subreddit (but has grown significantly in the last year!) and has plenty of insightful discussions and ideas.

You should take a look!