Aiden said - "The world's fertility rate has already dropped below replacement levels, but the population is still growing because people are living longer."

Answer- "Replacement Levels" are a moving target if less deaths occur births need to be revised down. This will become much more important if Aubrey de Grey is correct about longevity.

http://www.encyclopedia.com/social-sciences/encyclopedias-almanacs-transcripts-and-maps/fertility-below-replacement

Basically you can't aim for a certain birth rate and then say it's not our fault due to the increasing life span. All countries need to take responsibility for their populations. This is a problem when leaders claim changed circumstances when the change was predictable. Leaders are paid well should we really need to check up on them to make sure "their heart's in it"! Maybe we should check on them, demanding regular independent progress reports on key issues. Maybe there needs to be a "Promises Index" rating/ ranking how well leaders meet their promises based on the opinion of the stakeholders with a weighting based on "Care Factor".
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Aiden said - "And air pollution has little to do with population - it's much more to do with lack of, or lack of enforcement of, environmental regulations."

Answer- It's both demand side population and supply side regulation of producers

Dog,

Someone on the wireless (or the TV, I forget which) off-handedly remarked yesterday that the current world population (say 2016) was 7.2 billion. Above, I noted that the UN had calculated that

"World population will rise from 7 billion in 2010 to 8.5 billion in 2030 (i.e. a rise of 1.5 billion in twenty years), to 9.8 billion in 2050 (a rise of 1.3 billion in twenty years) and to 11.2 billion in 2100 (a rise of 1.4 billion in fifty years)."

So world population has risen only 0.2 billion in six years (roughly 33 million/year) (even though population has been boosted by people living longer) when it was expected to rise by 1.5 billion in twenty years (or 75 million/year). Could it be that the projections are already over-shooting by having assumed more than twice as much annual growth as is actually occurring ? If so, could it be that the down-turn is happening much faster than projected for ? That the world population in 2030 won't be anywhere near 8.5 billion, but more like 7.6-7.7 billion ? And more like 8.4 billion by 2050 ? And more like 9.5 billion by 2100, and more or less steady-state, if not on there verge of declining ?

The world is a big place, a dirty big place, real big. I can still only calculate in square miles, not sq km, but I think there are about 70 million sq. miles of land. So currently, on average, each sq. mile supports about 105-110 people. On the above revised calculation, by 2100, each sq mile will support just under 140 people, or about 30-35 % more than now. Can innovative technology improve production across the world by 30-35 % in eighty years ? I think so. By 100 % ? Very possibly. Possibly, world food production won't even be an issue by 2100, when population growth has stabilised. Perhaps a major problem of the 22nd Century will be gluttony.

Joe

Looking at the land mass alone is futile because a lot of it is uninhabitable. My coarse guess is that by taking into account mountains, snow covered area, flood land, swamps, airports, huge facilities etc.etc. dramatically reduces this "plenty of land" argument. Then, are humans really interested in becoming even more tightly packed ? Where will the extra required farmland be ? There's a point where we have to simply make a decision of quality of life vs plain existence. I know which side I'd chose.
There's also the one question hardly anuone considers in such debates & that is conpatibility of various ethnic hroups such as the situation has become in Europe & is morphing here right now.
We really have reach a stage which most of us still view as utopian, it's no longer so, take off the blinkers, it's arrived.

*Loudmouth said "World population will rise from 7 billion in 2010 to 8.5 billion in 2030 (i.e. a rise of 1.5 billion in twenty years), to 9.8 billion in 2050 (a rise of 1.3 billion in twenty years) and to 11.2 billion in 2100 (a rise of 1.4 billion in fifty years)."

*Answer- Your quote with respect Loudmouth didn't include a link so I found your quote through Google. You appear to have miscalculated some of your figures.

http://www.un.org/en/development/desa/news/population/2015-report.html

"World population projected to reach 9.7 billion by 2050
29 July 2015, New York- The current world population of 7.3 billion is expected to reach 8.5 billion by 2030, 9.7 billion in 2050 and 11.2 billion in 2100, according to a new UN DESA report, “World Population Prospects: The 2015 Revision”, launched today."

*So correcting ...

Loudmouth said - (i.e. a rise of 1.5 billion in twenty years- roughly 33 million/year) (it was expected to rise by 1.5 billion in twenty years or 75 million/year)
Answer- (Rise of 1.4 billion in fifteen years as the article was written in 2015 not 2010 = 93 million/ year- x2.8 what Loudmouth calculated 33 M/year.)

So the population of the world based on UN estimates will increase by 16% by 2030 (8.5/7.3 billion= 1.16).

For those that "already feel cramped by population, as is their democratic right", I can understand when they see the northwards direction as "horrifying" when they believe it should be heading southwards.

Anyway as I've said many times looking at the world and dividing it up among the people is the wrong strategy to control population because "population growth is culture based" and needs to be "addressed at the level of cultures or nations".

When nations and "cultures are irresponsible" with managing their population they "impact on their neighbours"- and create international threats. It's similar to "a military buildup" on the border as a precursor to invasion. (See John Stuart Mill- On Liberty).

It's necessary to "solve the problem at the level of the problem" otherwise "the bad behavior continues".

What needs to be done- Those nations and cultures that are approaching or beyond the carrying capacity of their land calculated based on land structure deserts, mountains, snow covered area, flood land, swamps (as Individual said) need to be "ranked as bad population actors" and managed by the international community or in the worst case by individual nations.

I agree with Individual when he says "the one question hardly anyone considers in such debates & that is compatibility of various ethnic groups". "Different cultures have different values" perhaps the ones that are pushing the clash of cultures has an agenda. Sun Tzu talks about getting your enemies to fight amongst themselves- divide alliances. The question is which sub-cultures have desire and power to implement it- then we can understand. Journalists talk of the 5W's- who, what, why, how, when.

Loudmouth seems to be taking the land area of the planet and dividing it by the number of people- as if people are the only important things on the land- Anthroparcy. The lands are controlled by cultures and nations- they are the custodians and protectors of the land- some are better custodians than others- the size of population on the land is the main (demand side) thing causing damage to wildlife. Supply side issues also affect wildlife- however supply side issues (in business) are usually predicated on market demand. When commodities are sold on a world market the pressure to use land, impact on wildlife, local prices become greater from greater demand.

Hi Dog,

Sorry for writing about the size of the planet's surface in relation to its human population, but somebody did mention over-population and I mistakenly thought the limited amount of land, in relation to human population, might have something to do with their alarm. Of course there are uninhabitable deserts and mountains, but on average .... . Of course, it depends how you use it: a farmer can plough up 1000 ha of land for himself and his family, on an average of say, 200 ha to the person; while an office block might occupy an area of 10 ha and employ a thousand people. A differential of 20,000.

Please check your maths. Even on the UN's own figures, it's clear that that rate of growth is declining. We might have been using different UN documents, by the way. But either way, it's clear that the rate of growth in world population is declining, and possibly faster than the UN is projecting.

Another historical major factor in population decline has been universal education: as John Caldwell showed, after countries initiated compulsory education, the average number of children that families had declined rapidly, since, instead of being a valuable asset around the house in assisting their mothers with child-rearing and their fathers on the farm, etc., children suddenly became something of a financial liability, not only not helping out as before, but requiring half-decent clothes, lunch money, shoes, exercise books, pens, etc.

Coupled with the old age pensions - and on top of major health advances between 1860 and 1950 - these were all factors which impacted greatly on population growth in countries which could afford them. The further education of girls and women accelerated that decline. And so it will slowly happen in the rest of the world. Maybe the sky isn't falling :)

Joe