About 12 years ago I proposed during class in school, that to save the planet we must reduce number of people living on Earth significantly and relatively quickly. Well the teacher thought that I was new Hitler (at least at first).
Just like you said, the point is that either people shouldn't have kids at all or have no more than 1. If whole Earth's population would do this, in 30years we will see a sharp fall in the population count. And in 60years it should be reduced by 30% at least [1].
If we will not do this now - our children, or grand children will not thank us.
[0] this is probably against HN ethos, though I couldn't resist
[1] It's completely out of my head, though if the perfect scenario would work - I guess it's a reasonable number.
I have seen more than enough people that claim to have no children for the sake of the Environment, only to go and buy pets and treat those like children; retarded children that will never learn to speak, walk in 2 feet, or become productive members of society, demanding constant attention for their natural lifespan, and which will age rapidly and die in their teens, - and have valuable medical resources expended in heroic efforts to futily prolongue their agony for weeks/months. You could claim that the pet dies early and does not produce offspring, but then the pet owner will likely mourn for a few weeks and then go to the pet store and start all over again.
Third world countries have the 'capacity' to almost double world population (in case of medium growth scenario, hopefully population size will plateau at around 13 billion, I do not think that optimistic rapid decline is possible without rational action of global intervention to reduce population growth [0]), which IMHO sounds catastrophic. Because for next 50-100 years global population will be increasing rapidly and hopefully will stabilise after that, without any prospects of reduction for probably double of that time frame. Even if the population will start to decrease I think it may take at least few ages to reduce population size to what is today.
[0] https://en.wikipedia.org/wiki/File:World-Population-1800-210... , https://en.wikipedia.org/wiki/World_population_estimates
Individual judgement? Do we imagine some couples saying to themselves "We're not up to much genetically-speaking so - we'd better not have any kids"?
I think that global 1 child policy would be harsh [0], though, for the lack of better term, a 'perfect' medium between 'no child at all' policy and "increase human population until it's destruction" scenario.
In perfect case couple would have up to 1 offspring, thus global medium would be something like 0.9 or 0.8, or even less. Which will reduce global population by half in 50 years.
[0] It's harsh, though would be right thing to do so we will not proliferate and consume ourselves to the point of global destruction.
And all non developed countries will potentially add 3-5 billion to current population [0]
[0] on moderate forecast, IMHO optimistic sharp decline is not possible without very aggressive global intervention to population growth (either from rational human thinking or from ecological catastrophe). https://en.wikipedia.org/wiki/File:World-Population-1800-210..., https://en.wikipedia.org/wiki/World_population_estimates
We haven't done all we can to protect the environment. We haven't even tried that hard. It might be easier to reduce our personal impact to 10% than try to reduce the world's population by the same level.
We sit in font of computers the whole day. The disciplined ones runs when there is no immediate danger or prey. We don't attack or kill people when they make us angry. We don't have sex with everything that has a chance to bear offspring.
Now the main problem is that if you reduce your CO2 emission by 80% and you and all your offsprings have two kids and each consume at your reduced level, in just two generations, it would been better if you didn't have kids. Two generations after that even at the reduced consumption, you (by having kids) contribute to CO2 emission by a factor of 6 if you have just consumed all the meat and didn't have kids.
Geometric progression is a nasty nasty thing.
Two kids per couple isn't enough to cause population growth.
Two parents having two kids leads to the exact same number of people on the planet after the parents die.
We only see population growth with 3+ kids per couple, and that's becoming increasingly uncommon in developed countries.
Absolute immortality isn't a plausible scenario, but it's important to consider that as longevity increases, the reproductive rate that leads to a stable population must go down.
Whilst human population can't continue to grow on this planet indefinitely, there's plenty that can be done to push our societies in a direction that works with nature. That should be our focus.
To give one example of how working with nature benefits us all, check out this talk by William McDonough:
* Voluntary childlessness: https://en.wikipedia.org/wiki/Voluntary_childlessness
* Human extinction: https://en.wikipedia.org/wiki/Voluntary_Human_Extinction_MovementSo you can take the idea of volunteer depopulation farther. You first?
When I propose this idea the usual reaction is: "Are you the next Hitler? Do you want to kill everybody? Maybe you should kill yourself first!".
It's proposal not to proliferate ourselves to extinction, no one is proposing any mass genocide. IMHO [0], we are 2-3 generations from catastrophic survival problems (unfathomable problems due to climate change, lack of resources like drinkable water, etc.).
[0] completely pulling this out of my a, though I think it's reasonable scenario with current increasing rate of consuming ourselves to death.
Especially if you're doing well because the chances are your kid will grow up and drive for most of his life, fly in planes, obtain lots of stuff that requires CO2 emission in its production, and perhaps even consume meat. If you have multiple kids and they go on to have more kids etc, the environmental effect of having a kid becomes exponentially worse.
This doesn't mean that you don't deserve to be a parent, it is only natural to desire to be one. The closest orphanage will have many kids who are wishing for a warm home every day of the year. There are many impoverished and brilliant kids around the world who will live and die working under horrific conditions.
Now there is an argument to be made about you and your partner's genes being so exceptional that it would be more harmful to the society not to pass them to future generations. I guess it is up to the individual to make that judgement.