For most, it would require living in a smaller space, in a more urban area and is probably the most people can do to reduce that impact on the environment.
The energy spend that comes from living in detached single family home that multiplies all the distances mass has to travel back and forth from that home (and subsequent homes) dwarfs everything else.
But, for example, preferring walking to more energy efficient cycling means you need more calories => eat more => affect environment more.
Very often living healthy is at odds with being environment friendly. I do not say you should live unhealthy but lets not confuse those two things.
I guess a more accurate descriptor is “non car dependent living”.
And that’s just one event.
Being politically active and pushing for a carbon tax would do far more than any amount of individual lifestyle choices.
3. 4. 5. 4. are barely positive if positive at all (considering environment, some are definitely healthy)