The people I distrust least, ALL say that population decline is our biggest worry.
If it were any other species we were talking about the word we'd be using would be 'infestation'.
As far back as I can remember there was always famine in parts of the world. Nature is cruel - if a land isn't capable of sustaining a population then said population is culled. Now sure, that's not nice - of course you don't want anyone to suffer and die - least of all your own family and friends!! Helping to make a land more fertile - drilling for water etc - is good.
But increasingly we're taking people from cultures where you have a dozen kids expecting most to die. We're saving the kids, giving them all smartphones and internet access and encouraging them to flock to the West to be used as cheap labour, undercutting the native workforce.
Harsh as it sounds - sometimes you need to let people die. None of us can live for ever. Better to enjoy life than to make everyone utterly miserable in a futile attempt to prevent death.
If someone can't have children naturally - maybe, just maybe mother nature knows best? If someone has a genetic condition that would kill them in childhood without intervention - maybe, just maybe they shouldn't be helped to have children (thus flooding the gene pool with bad genes).
And if a landmass isn't capable of supporting life, then really you need to let nature work things out. There is a certain number of people that the UK landmass can support. And it's a LOT less than the current population. This makes us reliant on imports of food, which in turn undercuts local farmers rendering us utterly helpless.
And this is why I am looking at Ancient farming practices. I don't give a flying f**k about feeding the world. The world is screwed. I'm only interested in me and mine right now. Modern ways are all centralized. What we need is to return to distributed system. And we can all make a start with ourselves!!