Now I'm neither of the parents (comment parents) here, but I'm myself torn on the issue.

On one hand, having children will contribute to the overall higher consumption, meaning the environment eventually will suffer from the increase in population.

On the other hand, having children and raising them as good as you can, can offset the impact (or even have a better impact on climate change as a whole, even though the increase of consumption) other people have on the environment, if you "train" your child(s) to care for the environment.

I guess the reasoning is because humans are the worst thing that have ever happened to the environment, therefore by producing less humans, we produce less environmental damage.

less humans means less human impact on the planet