I'm all for choice. What about something like:
You may choose to reproduce, but only after you have achieved neutrality for yourself and your offspring?
Would that be an incentive for highly responsible ecological behaviour, i.e. reduced consumption, or an incentive to remain childless?
Reproduction should neither be punishment or reward, because making either so is just punishing the poor, with less spending flexibility or access to multiple reliable birth control. Being able to be carbon neutral in the US especially, make no mistake, is a privilege.
And considering the problems in the consumer sector are far and away the much smaller, already low birthrate wealthy class, I'd much rather go after companies and 1%ers enabling this behavior than general consumers themselves.
Places like Amazon, companies slowing ecological research like Enron, city planners that prioritize roads over green spaces and public transport, supermarkets which window-shopping make egregious amounts of food waste, farmers and their retail partners preforming monoculturing and hot housing and water wasting non-native staple foods as their primary earners (aka avocado and almonds farming), clear cutting for palm oil, housing manufacturers making great swaths of impractical suburbs that just sit empty, Jeff Bezos, whose super yaht produces more carbon waste than near 500 of you etc etc.