This is a crazy thread so let me add my 0.02

1) Biology teaches us that if a population reaches anywhere remotely near the carrying capacity of a closed ecosystem you will have massive population decline.

Since the human population of earth keeps increasing at a fast rate that means we are no where near the carrying capacity of earth.

I am not saying that we should stick our heads in the sand and say "all is OK so who cares" but there seems to be a few people that believe that we have already surpassed it, and that is obviously wrong.

So let's look at food supply and population growth

2) IMHO the biggest issue with food supply today and the foreseeable future is not food production but distribution and human stupidity.

a) distribution is relatively easy to understand.Have you ever finished eating and there was still food on your plate and you threw it out? If the person that was hungry had that extra food from the get go maybe none of you would be hungry. But it does not stop there, have you ever thrown out food because it went bad or you got tired of eating left overs? what do you think (at a larger scale) happens at the restaurant or at the store or at the farm?

the better the distribution the higher the carrying capacity becomes.

b) human stupidity is a bit more tricky since it is a bit of a catch all. Also People should not take it seriously since it is a societal and not an individual issue.

I have a home with a yard, some trees, some flowers, hedges and some grass (nothing out of the ordinary). Now if the previous owners had planted fruit trees instead of the trees I have, those trees would be producing food, if I planted vegetables or shrubs that give fruits instead of flowers, that would mean more food and if instead of grass it was dandelion greens, herbs and other greenery you can walk on that is edible my yard would produce even more food. But it does not make sense to cut down those healthy huge old trees and if I removed my hedges and planted blueberry bushes or raspberry bushes people would think I am nuts and if I removed my grass and went with dandelions, my neighbour that mows his lawn twice a week, goes over it with tweezers and a vacuum would go nuts.

If people have planted a home garden, has everything been perfect? probably not, the same is true with all food, There are many tons of oddities produced constantly and many get thrown away because they don't conform to the standard.

Think of that jeans you are wearing, it is made of cotton, even though it is still wearable, you get rid of it because it is no longer fashionable, but that cotton needed to grow and that means that field and those resources could not be used to grow food. it is the same for any piece of clothing made from any natural fiber.

.....

b) population control:
first I am sure we can all agree that some people should have never had children. Unfortunately that is easier to determine once it is too late.

second on sterilizing part of the population that is a crazy idea since except for those few exceptions who is to decide on the chriteria and make the the final decision on who might make a good parent or not.

thirdly as someone else stated, if you sterilize everyone in a few years there will be no one left and before that no one to work so that you can retire or be taken care of in your old age.

fourthly a healthy population needs to have a triangular shape it does mean population expantion, but look at this graph


it is based on reproductive age, but that is not that different from "socialy productive" age (making good money and paying lots of taxes) take out some of the lower yellow and add them to the blue and some of the orange and add them to the yellow and you would be there. But that being said, like the graph shows Canada falls into the small growth rate and that is why there is talk of raising retirement age [Link: thestar.com] The yellow part needs to work for the easier blue and harder orange part to exist. IF population control is really necessary then shrinking the orange part makes more logical sense (but not emotional sense) then limiting births in order to get one of the pyramids to the right

3) washrooms.

I don't get the issue, does anyone have gender segregated bathrooms at home? the urinals can be a bit of an issue (not enough privacy in general) but when it comes to stalls just put a longer door if needed and let everyone use any of them it will also help with lineups.