If you want to be certain that you’re making a difference then plant trees.
For example, in just a few hours it took me to buy trees at a wholesale nursery and bike them home in a bike cart and plant them… That small investment of money and time has grown significantly in the past 18 years.
In Santa Cruz, California at HWY1 & Chestnut where I used to live. Other than the one street tree closest to this crazy intersection there was no shelter from the noise. So I planted some trees and now you can’t even see the house from the street!
Small efforts can get big sometimes… Used to live in this house in Santa Cruz ’92-96. All the tree tops around this house were planted by me! Long live the trees!!!