[bad-joke]

> If instead of almost 8 billion humans there were 4 billions we wouldn't be in this mess either.

I'm not sure your logic follows. The US outputs roughly 13% of global CO2 emissions despite having 4% of the world population.

If the ratio of population to CO2 output was scaled in this case, 7.5 billion US citizens would output 118,000 Mt of CO2 per year. Halving that (to less than 4 billion humans) would be 59,000 Mt of CO2 per year, and the current global output is 37,000 Mt per year.

[pier25]

Half the population would produce half the emissions and consume half the resources considering the same emissions per capita per country and equivalent population density per country.

[sanbor]

We cannot kill half of the population but we can consume half. We could avoid replacing phones every two years. We could eat less meat. We could avoid having so many cars.

[zzo38computer]

Yes, they have too many cars, and also make stuff not enough durable. If you (and I) do not have any children then human population of future can be reduced hopefully; currently human population is too much but that is one way to reduce in future. There is some other way as well, I think (but, you should not just kill everyone (regardless of their species) just to reduce the population; only for self-defense or for food).

[pier25]

We could consume half, we could even impose laws controlling consumption of resources, natality, etc, but since these would be pretty unpopular no politician would consider that unless it's probably too late.

[shapiro92]

you cannot consume half. (not talking about phones) but if a human needs X food then he cant half it. you can replace with X with half Y and half Z but the logistics is the same.

The issue is overpopulation. You need a specific amount of resources to sustain that number. you cant half it without halfing the population

[sanbor]

How do you explain that people in US produces 4 times the average CO2 emissions?

[LaundroMat]

Surely you know what that first sentence sounds like :)