It's not a matter of spin, it' a matter of reality. At some point we need to move to a sustainable economic model. The alternative is eventual catastrophe. By definition an unsustainable economy, which does not become sustainable, will eventually not be sustained.
I also don't agree the consequences have to be 'very' negative. However that's such a vague and undefined term, it could mean anything. I believe the costs are manageable and that a stable, sustainable economy can be compatible with stable or rising living standards.
A non-increasing population leads to economic stagnation (at best). That, coupled with a decline in religiosity leading to a loss of societal cohesion will eventually bring down the whole house of cards that is modern civilization.
Famine, war, etc. follows. And we're back to a less populated world with high infant mortality again. Hard times lead to a return to religiosity and large families.
> A non-increasing population leads to economic stagnation (at best).
Kind of like in agriculture, there's "intensive" economic growth and "extensive" economic growth. Intensive being when the same number of people are more productive and extensive being when you have more people.
You can have economic growth with a stable population. Heck, Romania's having economic growth while its population is declining! (a population loss of about 10% in the last 15 years, during which time its economy doubled)
Harvest festivals were religious- or at least tied up in religion.
You can't just take a core element of a heavy intertwined, complex system without collateral damage. It's like deleting a file in a spaghetti codebase. Half the codebase interacts with any given file in some way or other.
that sounds like a problem with our economic system more than with our reproductive trends. At a certain point population growth would have had to plateau, it couldn't have continued growing forever.