And that taboo is probably rooted in evolutionary psychology, people have a genetically driven tendency to criticize those who advocate having less children? So could there be an instinctual drive behind it?
https://www.flashpack.com/solo/relationships/dont-want-kids-...
1) Limiting number of children in rich countries. This is what your links talk about I think. Yes, perhaps there is a taboo in place here.
Is that relevant to sustainability crisis though? Population is already declining in rich countries, quite naturally.
2) Limiting number of children in poorer countries. Well, as in the article pointed to in a sibling comment, "Richest 1% account for more carbon emissions than poorest 66%"...
So by saying that overpopulation is the root of the crisis -- are you not saying that it may be better that 10 poor people are not born, than for rich people to do minor changes to their lifestyle?
I definitely would say that and would argue it needs to be way more than 10.
If you want to solve manmade climate change you need to solve the demand for goods that cause it. You lower demand by increasing the the supply (can't do that because that increases the emissions you try bringing down) or you increase its price making only the very rich able to afford it and delaying the problem for a decade till population catches up. We already see it with migrant crisis all over the west - both Europe and US.
You do this decade after decade, again and again each time creating more and more privileged cast that can afford it (current policy) and in essence pushing the rest of the civilisation further and further into poverty as they will never catch up and if they do - new legislation will bring them down again to mask the issue once more.
An example of that would be farmers in Europe protesting removal of diesel subsidies or just in general people being able to afford smaller and smaller cars due to taxation in Europe every year.
The problem with these "minor changes to their lifestyle" is that they need to accommodate exponentially growing population that already is a magnitude or more higher than persons who need to adjust.
We are talking about 90%+ reduction in what you call "minor changes" to achieve emission equilibrium to begin with and add that with exponentially growing population and its simply not feasible not due to lack of compassion from top percentile but because changes like these would completely anihilate the modern human civilisation and bringing it back hundreds of years.
As an example theres a very informative video on what happens to country and infrastructure when 4 million people join the power grid in a decade [1] Imagine that scaled to 4 billion and the extreme worldwide devastation.
Population control is the only way to solve climate change and it needs to be reduced everywhere but especially in the undeveloped nations as they have the most potential of bringing everything down.