Bill McKibben's "Maybe One" dealt with this issue wisely and humanely (he and his wife have one child). Part of the problem in the sibling decision is the lingering and ill-founded idea that "only children" are more selfish, etc., which McKibben faces head-on and dispels in his book. Remember, siblings don't always get along, let alone support each other when the going gets rough. If you raise your one kid to make lasting friends, s/he's got just as good a shot at a support network.

Full disclosure: I have no kids, my choice primarily driven by population concerns. I also have absolutely no regrets.

Adopting another child makes sense. Often that child is already here and needs a family.

Recycle a used child. Consider an older one, even. They're easier to get and you'll be doing society an even bigger favor by refurbishing them with love and attachment and stability.

Then your kid will have a sibling, someone will have a home, and you won't be making anyone new. It's the finest form of recycling, no?

In spite of what Pablo says, every additional American is another nail in the coffin for the continuation of life on this planet. Your so-called environmental household is still unsustainable. Vegetable oil fueled cars still directly contribute to global warming (see last week's Science) and have a HUGE indirect effect by terrorizing cyclists and pedestrians back into their cars, which leads to even more idling autos. Raise one child, raise him or her to the best of your ability, and be happy.

Please consider foster children and/or adoption. Both of these will provide companionship for your current child with the added advantage of helping him/her learn to form tight bonds and empathize with someone who may be substantially different in terms of genetic heritage and early life experiences.

By the way Pablo, if we do not begin to have mandatory reproduction limits soon, we will surely have INVOLUNTARY human extinction. Unless, of course, we can find and reach those additional planets we will need to sustain them all.

There are WAY more than enough humans around for the next few decades.

voluntary or mandatory population control is not necessary. limits on food availability and urban enhanced spread of disease and violence will kill off enough people.

You will be contributing to global stupidity. People as irrational as you should not multiply.

Like sooty1, my decision not to have children was based primarily on concerns about the planet. I just couldn't see how I could decide to add to the already overwhelming problem of population, a problem that WAY too many people dismiss as being "irrelevant". Hell, somebody recently responded to my comment about it here by calling such concerns a "red herring"! How anyone can be so blinkered is beyond me. It seems to me that ALL of our environmental problems can be traced simply to having too many people. This planet is perfectly capable of sustaining a reasonable population. After all, it did exactly that for a hell of a long time, didn't it?

It's time for humanity to wake up and stop thinking so selfishly. Reproducing your own personal genetics is no longer a viable way to look at things. We're breeding ourselves out of our habitat, and it won't be too long before nightmare scenarios like Harry Harrison's Make Room! Make Room! come to pass. What will we do then, start executing useless members of the population? (Though I'm sure there are those who would welcome just such an alternative.)

Wouldn't trade them for anything. Not even a dog.

Yeah, driving a hybrid vehicle and being able to afford organic produce *totally* justifies having another kid. *rolls eyes*

"It's time for humanity to wake up and stop thinking so selfishly. Reproducing your own personal genetics is no longer a viable way to look at things."

If this is how you view raising children, then I am glad you do not have any. Decisions about whether to have (or adopt) children are complicated in many ways, including environmental ways; but it is about a lot more than genetic reproduction. These are children, full blooded human beings, the things that make up families, communities, the stuff that life itself is all about for many, many people.

My husband and I have been discussing this issue at length. He strongly advocates for the one child policy in our family while I search desperately in my own heart for justification to add another. I've considered adoption but the process is long and expensive and maybe better left to those who want it more than we do. I have also considered foster parenting and I think we might turn to that in the future when the children we decide to have (one or two, however it turns out) are a little older.

The best answer I can come up with for our current dilemma is the argument from utilitarianism, what if everyone did what I want to do? Well, like the original writer, we recycle, eat organic, make our own food at home, try to buy used or to simply not buy at all. We live in new york which makes public transportation less of a lifestyle choice and more of a necessity. And, the one that sticks out for me is if everyone had only 2 kids, the population would gradually and steadily decrease over time.

I know that it's an idealistic justification. Obviously many people do not share our values, or our habits, and many people don't consider environmental issues to be relevant to family planning, but I cling to it just the same. The desire for children is not rational and it can be very hard to repress it based on logic. Given my natural impulses I might consider more than 2 kids to be the ideal family size but will limit myself strictly to 2 in recognition of the times we live in. It's a compromise that I hope can be sustained for my family and the world.

But go right ahead, I chose to have none, so have a couple extra on me.