Be a vegetarian, ride your bike or walk to work, and live in a high-efficiency apartment in the city using solar and wind-generated electricity. Have 2 or fewer

Be a vegetarian, ride your bike or walk to work, and live in a high-efficiency apartment in the city using solar and wind-generated electricity. Have 2 or fewer kids. Take holidays via train. Buy less single use crap. Bonus! Give everyone 6 months holiday a year because humanity has more crap than it's ever needed but not enough time. I mean, how much lower is that? I wouldn't mind it.