In an article at The Conversation, philosophy Professor Trevor Hedberg said having a large family may be unethical because children produce more carbon emissions than can be offset by recycling and driving fuel-efficient cars.

Worse, one extra child “may be responsible for the severe suffering, or even death, of one or two future people” because of their impact on the environment, he wrote.

Hedberg said he believes children occupy a “messy” space somewhere in the middle between luxury and necessity.

“For most people today, having their own biological children is not essential to health or survival,” he wrote.