PLANT MORE TREES!
Trees not only improve our air quality and smog levels, they provide shade on hot summer days. I live on a busy street in Los Angeles and have noticed the lack of trees along my street. I though it would be great to transform the landscape and have trees running along my boulevard. I did a little bit of research and discovered Los Angeles has several programs for people interested in planting a tree.

www.Northeasttrees.org will give you a free tree as long as you promise to water it (I do believe you need to contact the city planning before planting in the area between sidewalk and street.) All you need to do is some digging and consistent watering while the tree grows and establishes itself.