The math is already out there on what rate of new childbirths can the planet sustain. Or what rate would bring the world population down. If we bring it down from 8 billion to 7 billion and leave it there for a generation, while implementing structural changes in our society - then we will see improvement.

To lose weight - no one ever says - don't eat. Most will say eat less and eat right.

The same logic applies to global warming.

To answer your initial question - no I don't think you're selfish.

In earlier generations the decision to have a child was decided between two people - not today unfortunately. Today, that decision has a ripple effect and needs to be considered more broadly.

One or two children per couple around the globe will give us all what we need and most importantly, time for the planet to heal.