... Then, if the population has to be reduced faster than birth control allows, I would consider it most fair to simply lower the food production to a sustainable level and then distribute the food equally on those who work (assuming that most, if not all, work in such a society serves the common good) and perhaps to some extent those who don’t. It would not be fair, but it would be the least unfair because it would ensure natural selection over human selection and I think it would be, as CCGW mentions, more executable than other kinds of depopulation schemes, many of whom would border to barbarism as they are both unjust and unnecessary.
...
Rubikscube, i agree with most of the rest of your post, but the quoted part, i can't fully agree with. I haev a feeling that you, and quite many of other people here, do not fully realize the circumstances this planet is at, at this time, and consequences of those cicumstances.
This is due to massive and ongoing campaign of disinformation, which is being done in mass media (including internet) by several powerful and involved parties; the one most often named party of the sort - is oil and gas industry (with their lobbyists, "pocket" (aka "pet") scientists, and such). But there are few others, too.
Generally, as far as modern fair and proper science knows, AGW will reach at least +4 degrees celcius above pre-industrial during 21st century, possibly by ~2050 or so. There are relatively simple physical reasons to this:
1. Earth demonstrates amazingly permanent correlation between amount of CO2 and temperature, as evident from ice cores research;
2. Amount of CO2 currently in the athmosphere is corresponding to much higher than +4C above pre-industrial warming;
3. There is a time lag, estimated to be some 30...40 years, between increase of CO2 in the athmosphere and actual realization of more than a half of expected land surface temperature rise, caused by the huge thermal capacity of the world ocean (mainly). As such, present days temperatures correspond to ~1970s athmospheric concentrations, at best, and as such, huge CO2 emissions since 1970s are largely not realized yet in form of the temperature rise, - but in a few decades, most of it will be realized;
4. There is a huge amount of aerosols in the athmosphere presently, causing the effect known as "global dimming", which masks (for many regions of the world) the true extent of the AGW. As long as mankind continues to increase aerosol output (read about air pollution in China to see what i mean, for example), - global dimming will continue to temporarily negate much, or at times, even all, of temperature increase caused by AGW. However, aerosols do not stay in the air for more than several months or few years (unlike CO2, which stays for many centuries, and CH4, which stays for several years). As such, any significant decrease in aerosol output (or stopping it altogether), - will cause a massive jump in temperatures in a matter of very few years. Estimates i've seen in a few papers about this - are some _additional_ +1,8...4,2 degrees C for average world surface temperature (means, even higher jump than that for land surface);
5. Methane content of permafrosts. Hopefully, most people here are aware - annual methane emissions in Arctic are already increasing massively every year, since ~2010, and there is no sign this process wouldn't accelerate further;
6. All the other positive feedback, like dropping albedo positive feedback, higher-temperatures = more_burning_forests = more GHGs = higher temperatures positive feedback, and so on and so forth.
There is, of course, some negative feedbacks in the system, and "shock absorbers", too; the big "shock absorber" is the ocean, with its already mentioned enourmous thermal capacity. The main negative feedback is, of course, the Stefan-Boltzman law (the hotter Earth gets, the more energy it emits into space per second, see
http://en.wikipedia.org/wiki/Stefan%E2%80%93Boltzmann_law ), which limits possible AGW on Earth to some ~ +15...+20C in very worst circumstance (probably much less than that), because Sun's energy output is practically constant. Still, even +6...+8C of AGW spells disaster to mankind and to the biosphere (given the speed of it - happening within ~1...2 centuries, not during several thousands of years and on a lower scale, which was the case with glacial periods), as far as i know; and +3...+4C is said to be the amount which triggers several massive additional positive feedbacks, thus initiating further warming to some +6C or higher above preindustrial.
In those circumstances, CO2 content remains very important "catalyst". Generally, the higher it is, the faster and further AGW will end up going. Nowadays, we add ~3 ppm of CO2 to the athmosphere (i mean the mankind). A single decade is +30ppm or so. This is very substantial.
I've already mentioned that non-destructive attempts to reverse the trend - proved to be unsuccessful. Kyoto, IPCC, all the UN activities, individual countries (rather humble) achievement in reducing CO2, - all those didn't even slow the trend of rising CO2, least stopped it. While in reality, mankind needs to reduce CO2 emissions extremely very fast as a very minimum measure (in fact, to exclude risk of planetary-scale catastrohpe, CO2 levels in the athmosphere needs to be reduced - an equivalent to "negative" CO2 emissions: instead of releasing 30+ gigatons of carbon in CO2 form into the athmosphere every year, to be truly safe, mankind needs to _capture_ dozens of gigatons of CO2 from the athmosphere. Right now, we're at 400 ppm, while historical normal is ~280 ppm, and long-term safe limit, by all means, can't be higher than 350 ppm. Adding CO2 into the oxygen-rich athmosphere - is a process with _generates_ energy, and tremendous amounts of it, too; removing CO2 from oxygen-rich athmosphere - is the opposite: it requires energy, and even much more energy than we get by burning carbon (since there are losses in both processes). I've paid special attention to CO2-removal technologies - they exist, the most promising one is high-tech bio technology, based on tiny green aquatic plants in a controlled environement - large transparent tubes, - under the sun; then there is CO2 capture and storage, and few others; still, none of those promise any chance of any large-scale implementtion, for various reasons such as resource limits, poor investment viability (if any), dangers of catastrophic release of vast masses of stored CO2, too high energy requirements, etc). Therefore, the real choice mankind has, imho, is this: either sit idle and go business as usual, emitting even much more CO2 from fossils than was emitted up to date, total, and use technology and remaining resources to keep prolonging its existance on a short-term basis, - the end result being a planet seriously uninhabitable by humans, except very few high-elevation continental areas (cold enough and far-from-oceans enough to not have regular cataclismic weather events, and elevated high enough to stay above vast majority of various pollutants global civilization will leave behind, including radioactive ones); or, do the forced depopulation soon, reducing its numbers to 0,5...2 billions, and then do its best to mitigate effects of (eventually much weaker than in the 1st case) AGW. The former scenario will result in nearly dead planet by 2100. The latter scenario gives some chances to keep much of Earth alive (in terms of other species, as well as humans, that is).
The time here is of the essense, though. Given current athmospheric GHGs content, aerosols content, Arctic situation, and resource consumption levels, if the massive forced depopulation won't be done within next 10...15 years, - then there won't be much left for global civilization (whatever it'd be) to work with. Mitigating AGW requires large industrial power sustained for centuries (for at least 4 centuries as far as i can tell), and this requires substantial reserves of resources left. Won't be the case if 7+ billions world will keep doing business as usual for 3+ decades.
And this was only about CO2 and a bit about CH4, only. There are in fact other problems of fundamentally important nature (
http://en.wikipedia.org/wiki/Planetary_boundaries is a good start), and some of those problems are already beyond critical. Others are close to critical, and worsening. Any much more of "business as usual", and we can kiss even faint hope of "barely inhabitable" Earth goodbye: it'll really go berserk on us after a few decades (thermal lag is not the only lag - ecosystems have their own substantial reserve of resilience, which, once exhausted, leads to very ugly things, like insects multiplying dramatically and eating pretty much all green plants in a region during a single season, bugs destroying forests, widespread epidemies of humans and/or animals and/or plants - yep, green plants have their own epidemies if things go much wrong, etc). Because the current situation is created by merely some ~50 years of most intense usage of Earth by mankind; few more decades like that, and we'll kill her for good.
That's why there is NO TIME for any methods which do not involve killing humans. Simply allowing everyone alive to live - is a death sentense to Earth (and quite likely, to human species as a whole).
This is a very, very unpleasant truth. We are in a desperate situation. But pretending this is not the case - is one of most DISQUSTING behaviours possible for a sentient being, in my humble opinion. Not knowing about it - is understandable, which this post hopefully helps to address. Honestly, i'd never ever start this topic if there could be any much hope for "soft" - i.e., without killing, - depopulation methods to suffice. But afaik, there is not.
Still, the question is: is it barbaric more than it's nesessary, or is it more nesessary (to save much life - human and non-human, - on most of land surface of Earth, and life in oceans) than barbaric? I am genuinely interested in the answer, and i am unable to find the answer myself with certainty. My personal _guess_ is that it's more nesessary than barbaric; but, of course, being only a guess, i am ready for it to end up being wrong.
P.S. I would be most grateful if anybody could convincingly demonstrate that i am wrong, - with facts in hand.