OK this isn't going to get rid of the CO2 or decrease your energy usage but it may make your life more comfortable.
A while back I came across a book called "Allergy Free Gardening". It looks at various plants and trees and rates their allergy potential. I didn't realize that many trees are separately sexed. There are male and female trees. Male trees produce pollen. We tend to plant fruitless trees (male) in cities and they cause allergy. The book is easy to follow and is a good compliment to the Sunset Western Garden Book or similar books. Unfortunately, I can't find my copy
I may have to buy another one.
Allergy-Free-Gardening