Today I skip the nonsense, and go with Green. The more green we see, the more clean air their will be. Click on the title of this post and it will give you 100 ways to make our world green. Scroll to the bottom for the list.
Plants take carbon dioxide from the air and produce oxygen as a waste product. More Green Plants, the more Oxygen to breathe.
And the real plus side is they are beautiful to look at.