Zero Population Growth - Fact or Fiction?

[Puke]

lower your happyness, environmental resistance, and reproduction as far as they will go. if that does not do it, nothing will, short of modding the game.

if you are going to mod the game, you might as well just take away their access to colonization technology (by putting a prerequisite on it, and giving everyone else the racial technology that grants colonization) like in p&n.