Interesting question
You know, as I read your piece, I questioned why I want to have children.
While I don't think the evils in the world is enough reason to not have children, I agree that children contribute to the problems indirectly.
Honestly, I would say not having children is the best cause. If you feel like raising a child, there are so many children looking for homes.
Over here in my country, politicians would bleed the country dry just so that their friends and family members have it good. I figure that if there were no one to inherit their [ill-gotten] wealth, their contentment level will probably be lower
But then, I'm selfish and egoistic. I want my own. I want to think my own semen spawned a mancub. I want to be able to join other parents as they talk about the challenges of raising children. (plus, I think my gf really wants to play mother)