I see several parts to the problem where many people believe the doomer overpopulation myths.
The fear story resonates with deep caveman fears of starvation. Any individual person can experience hunger. This reinforces and validates the fear of potential starvation.
The small scale and valid fears and issues for individuals and small groups do not match up to real global risk. There are counter-intuitive aspects.
Is an objection – technical or some other subject relevant? I disregarded areas that I do not impact the core question of whether overpopulation is a true risk.
Scale of overpopulation issue for the world. 30% increase by 2050, 60%-200% increase by 2100. 100%-400% by 2150.
Nations and the world have far more margin for keeping people fed than people realize. We are NOT barely getting by. The avg person in the US eats 222 lbs of meat. USDA recommends that adults eat 5-6 ounces of protein daily, avg person will eat 10 ounces of meat and poultry each day in 2018. 30-40% of food is wasted in the US.
This means 20-30% underproduction would barely be noticed. Prices would go up on certain items which would shave demand. Eventually, this would trigger simple policies to reduce food waste. 10-20% gains from food waste reductions are relatively easy. This is so unimportant that most places do not bother. With a bit more time, an adaptation to 50-60% less food could be handled without people feeling like they are sacrificing. 90% reductions would be more like UK rationing.
Food production is increasing by a lot. The productivity of agricultural land will triple by 2030-2040. This not magic. Dozens of hectares with higher productivity are being grown now. China and other nations will scale them up.
This is all before going to building a lot of greenhouses which can boost productivity by 10-30 times. This is before the possible success of factory grown meat. Factory grown meat is now sold in restaurants. People pay more for the meat at high-end restaurants. It can be made to taste better. What if did not taste as good? Is it unnatural? People did not ask those questions about chicken nuggets. People love those things.
Factory grown meat can boost food productivity by 10X in terms of energy and water.
So we already have 2 to 3 times the food than we really need. The world can drop by 10 times and get by. Food production will go up 3 times within 20 years using business as usual agriculture. There is an option to use greenhouses on a larger scale for 30 times more food. Dedicated skyscrapers for greenhouses can boost food produced in a spot by 100X beyond greenhouses.
Factory produced meat can increase food production efficiency in terms of energy and water by 10X or even 100X.
Overpopulation was at most 3X by 2100 and 5X by 2150.
I will not bother to go into more complicated to explain solutions. I will just briefly mention that farmed fish takes about 1.5 times the weight in feed to produce the meat. Chicken also has low feed to meat ratios. This is compared to 8 to 10 times the feed to produce beef. There are other substitutions that could made to produce meat with less cost in water, land and energy.
There are proven methods in food science. If you do not have enough cocoa you mix a small amount with hazelnut and you get chocolate flavored nutella.