How many people will populate the earth in 2050?

I think: without climate protection, the decline in crude oil production (peak oil) and phosphate extraction will lead to a decline in fertilizer production and thus also in agricultural production, so that in 2050 the earth may still feed 4 billion (4G = 4 giga = 4 billion) can. (Oil consumption as in 1980). I think: with climate protection, thanks to the deliberate energy shortage and the coming wars of hunger, the above situation will be achieved as early as 2040. Does current politics provoke Russia in order to be able to depopulate Europe through a war and the subsequent post-war hunger? In 2050, 3G should still remain worldwide (oil consumption as in 1970).