Something about equating the choice to have kids with reducing the climate impact leaves me with an icky feeling. Not all humans have the same climate impact, so not all children would, either

I’ve had friends with kids. Children absolutely have a climate impact.

Diapers - disposable and reusable - have an impact. Car seats have an impact, and an expiration date. Kids outgrow clothes and shoes quickly, so replacements have to be created. (Yes, thrifting and large families can minimize (but not eliminate) that impact). Children are literal additional mouths to feed. Depending on the childrens’ age and quantity, the parents may need larger vehicles and houses.

And that’s just the required stuff. Children’s toys, gadgets, and hobbies also have climate impacts.