Biggest things you can do:
Biggest thing 1: walk, bicycle, and use public transportation
Biggest thing 2: get rid of your family's second and third cars
Biggest thing 3: get rid of your own car unless it is your home
Biggest thing 4: solar panels to heat water
Biggest thing 5: solar panels to provide all your house electricity
Biggest thing 6: change your diet to plant-based foods that you grow yourself or buy from local growers