It's not a perfect correlation, but I'd find it hard to believe that children don't share on average more of their outlook on life with their parents than with a random member of society.

It's a pretty bad, very risky "investment" in the environmental cause, though, because by the time your kids are old enough to vote, it'll be almost 20 years later already, the kids will be using up resources while they're growing up regardless of the ultimate outcome, and you can only pray in the end that they'll agree with you on values when they're adults. You can't just pump a new environmentalist out of the womb.