I love kids (and they love me too) but wouldn't want to be fully responsible for them in my current economic circumstances. If those circumstances were to improve significantly, I would like to look after some of the kids that are already here, either through fostering or open adoption. My husband and I would be great parents - we both have an abundance of love, compassion and patience, and I've spent many years as a teacher and nanny.
But we're both very ethical and very aware of the kind of world we would be bringing children into. Global warming and resource depletion means every generation is getting a crappier deal and inheriting more overwhelming problems than the one before. Also, the LAST thing the world needs if any of those problems are ever to be solved is more people living on it.
I don't think "ready" is the right way to frame it though. It implies there is a natural progression of maturity that inevitably results in wanting to make more people. I don't see it that way at all. As I say, different strokes for different folks.
It's not uncommon throughout nature for mammals to limit reproduction when resources are scarce. Not reproducing is a much more palatable option than eating our babies, like polar bears.