[thedoc (OP)]

Christopher Smith asked the Naked Scientists:
   Dear Chris,
I was just listening to your programme in Australia and there was a question about how can we reduce our impact on the earth.  All the answers were about eating less red meat and using less hot water. etc...

My question is .... why do educated people refuse to acknowledge the the impact of population is the most seriously dangerous contributing factor to social and environmental troubles ?  The world's peoples are completely reluctant to acknowledge this and even less reluctant to reduce the population of the world by reasonable means  ... such as contraception,  religious direction ,  reason ....    except when the troubles become too great we just go out and kill each other  . (wars and invasions and bombings of towns like Yemen and Alleppo  and the Ukraine  ect. 
And we all except that poverty and homelessness is an acceptable condition by doing nothing about  reducing the extreme competition that great populations create. 

I am angry about this.  It should be a question that scientists discuss.
Why do people refuse to see the wood for the trees.

yours sincerely,
Christopher Smith
What do you think?

[alancalverd]

Because science is for nerds, and it's difficult and sometimes alarming. Priests, politicians and philosophers have to address their flock of gullible taxpayers and industrialists whose profits depend on maintaining an inadequate supply to an expanding market. So everything is going to be OK as long as you buy the latest mobile phone and pay over the odds for your house, scare yourself about the afterlife, and kill anyone I disagree with..

Eventually, everyone will starve or dehydrate, but priests, politicans and philosophers won't be first in line, so who cares about the truth? Fact is that nearly all the world's problems could be averted by doing nothing - or at least by not making more babies. But where's the profit for parasites in that?

[evan_au]

People are happy for population limitation to happen somewhere else, but not to have it imposed on themselves.

One exception is China, which had a rigid "1 child" policy for many years.
- They are relaxing it now - if both parents were a single child, they can now replace themselves (2 children).
- China is concerned that they will now have an aging population, without young workers to support them
- But some social hangovers caused some anomalies. For traditional reasons, sons are far more welcome than daughters, so people tried to control nature, and now China has an excess of young males.

Another interesting case is Iran, which has a policy of allowing women to attend university.
- They are finding that more educated women make conscious choices about how many children they bear

The opposite scenario appears to be happening in Nigeria, where girls who attend school have been kidnapped and forced into marriage with strangers.

For "Western" countries (and Japan), a reduction of population growth seems to be a natural result in countries with a good health system (low infant mortality), a large middle class (they don't need lots of children to work the farm), a good education system and availability of sex education and effective contraception.

[alancalverd]

The "ageing population problem" is frankly nonsense. In the UK, at least, almost nobody contributes to the economy in the first 20 years of life, and we die off at such a rate beyond 60 that there is almost nobody left at 100. Just about half the population, i.e. those aged 20 to 60, work to support the other half.

Now if we limit reproduction to half of replacement level, the burden of youth on the working population decreases continuously. The old have already paid for their pensions, so all that is necessary is to supply a bit of social or medical care for those whose pension is inadequate. If you do the maths, it turns out that the "working fraction" actually increases from 0.5 to almost 0.6 under a continuing one-child program.

If we pursued this as a policy ion the UK we would end up with about one fifth of the present population in 100 years. Interestingly, this is the number that could live entirely sustainably in the UK.

Why don't we do it? Because house prices would tumble and there would be no need for industrial expansion. Politicians and economists would have to completely rethink their raison d'etre, and bank profits would decline. So that won't happen, will it?   

[chiralSPO]

It does seem that our global economy is the worst sort of pyramid scheme. If the population doesn't grow, GDP falls (even if GDP per capita increases, it is unlikely to keep up with a model that includes unbounded population growth).

It does annoy me that population limitations are not seriously considered in most policy discussions. Everybody says, "oh scientists will develop new technologies that will prevent calamity," and for a few centuries they have been right. But someday science won't have an answer beyond, "fewer people." And also, why must scientists today waste their precious time developing the technologies required to create enough bacon for 12.9 billion people? There are other things in this universe we might want to study...

[syhprum]

Malthus expounded this theory about 300 years ago but was supposed disproved by increasing technology but it is as true today as it ever was and will only work when living conditions get so bad that the death rate exceeds the birth rate

[Tim the Plumber]

Malthus expounded this theory about 300 years ago but was supposed disproved by increasing technology but it is as true today as it ever was and will only work when living conditions get so bad that the death rate exceeds the birth rate

I don't see any trouble at 20 billion people and more;

http://www.mnn.com/your-home/organic-farming-gardening/stories/desert-farm-grows-180000-tomato-plants-using-only-sun-and-seawater

[alancalverd]

You probably don't travel on the London Undergound, or live in Ethiopia.

[Tim the Plumber]

You probably don't travel on the London Undergound, or live in Ethiopia.

Tokyo is more crowded and continues without the need to depopulate. But then move out of London. Its' rubbish. The life here in Sheffield is much better.

Ethiopia is in a bad way because of bad governance. It is not bad due to a lack of resources including arrible land. It could be better than California but the locals are stupid.

If the rich world wanted food enough, ie. the price was high enough, then the place would be worth the effort to make decent and work as a good food growing area even to the point of doing the solar deslination thing there although that would need much more than 20 billion humans to justify.