3.15476771 × 1010. That’s 31 and a half billion for you. How do you get to this number?
Well, you take the total arable area of the planet Earth, multiply by the Calorie yield per area per year of rice, and then divide by the required yearly individual Calorie intake. Do you see where i am going? That would be how many people we could get eating rice. That would be our nutritional population cap. So, you know, people are all worked up about reaching 7 billion humans, how about 30?
We can’t eat only rice, you say, but potato can yield even more raw calories than it, and so can other starch roots (like manioc or cassava), maize can yield almost the same and maybe other grains can too, with high response varieties. That means even if we can’t achieve globally the same yield as rice’s, we shouldn’t be too far, if only we stop eating so much damn meat! This figure probably reaches other caps earlier, the most likely of them being the amount of available water.
But what i mean is not that we should have a population of 31 billion. What i am saying is: we should make allowance for the population going beyond the current estimates of 11 billion by 2050.
Not that it will happen… but it just might!
That doesn’t need to be a bad thing either. If, say, by 2090 the world reaches 20 billion people, it would be something like 3 people per each guy alive circa 1990. That would mean that our cultures would have been “diluted” 1/4 thin. Or “what is the role of centenarian traditions when we are now 10 times as many people as the founders, with likely 10 times as much good ideas?” It could go very, very extremely very bad but it could also be a fresh start, a free chance to re-dream the world we live in.
None of this needs the pre-judged, loaded, biased political readings that this kind of analysis tends to get.
For example: if you were playing an RTS game, like an Age of Empires or StarCraft or Dune2, what would you prefer — 20 of the most powerful units or 200 of the weaklings? The only sane answer is “depends”, but generally speaking the lots-of-weaklings strategy is much more promising than believed!
And if instead of a game we were talking about preserving the human genetic heritage? 1 billion obese americans or 20 billion starved indians? Which would be more likely to survive?
We must understand that it is not an old question, an old Malthusian dilemma, but actually a completely new scene.
(And, you know, all of the data used is based on the most shallow wikipedia-only research, but this page over there gives a bigger arable land estimation that would rise the final number to over 50 billion!)