That is only true in a system where everyone consumes the same resources. It isn’t true for our planet.
At present, you can remove 10 American and replace them with 1000 Ethiopians, and you have simultaneously increased population and reduced resource demands.
To be fair, they are. Klopptimist’s original comment was this.
But this is why I subscribe to the view that arguing for population control (as many do) is racist, if understandably and unintentionally so on the part of those who support it.
Population growth is already slowing in most parts of the world. There is a growing number of analysts who predict that by current trends global population will top out at between 8-9bn at around 2040, before beginning to sharply decline. A birth rate of 2.1 per woman is necessary to sustain population at current rates, and the rate is below this in most places outside Africa, and even in African its only significantly higher than this outside rural areas.
Reducing global population is already happening. 10bn people looks increasingly unlikely. There are not many parts of the world left where you can target specific policies to reduce population.
The population as driver for climate catastrophe argument was popularised in Paul Ehlrich’s book ‘The Population Bomb’ and his ideas have persisted today. Unfortunately he was guilty of some gross misunderstandings, lazy assumptions and downright racism. He wrote from his explorations of third world cities, describing their slums, begging, chaos, and pollution as a problem of over population. Unfortunately the cities he was describing were less populous that western cities like London, a Paris and New York, and the concept he was experiencing was actually poverty.
When Klopptimist’s says that reducing global population is the only solution (his slightly unfortunate phrase), it’s wrong, more than a little racist (because it’s an idea rooted in the stereotyped notions of foreign, often brown, people having loads of babies, and the only places where this is remotely true are rural populations of developing world nations who are absolutely not the problem here), and it would have the opposite effect that Klopptimist’s imagines.
The only way to reduce populations is through economic development, and through economic development (ie financial security, education, and cultural enrichment) birth rates fall. But those lifestyles come with a huge increase in consumption, resource use and carbon emissions. Any efforts to reduce population. Could easily result in a smaller global population emitting more CO2 than ever.
Population is in many ways a red herring. Poorer countries are pursuing economic development regardless of our approval or disapproval. Birth rates are falling naturally. The onus is on us to ensure that this development does not follow the resource intensive blueprint that we have laid down.
If every developing nation sees it as their right to have an fossil fuel powered development curve, then we are toast. And we can’t argue they should just stop, as we are the beneficiaries of 250 years of fossil fuel based development (often plundered from the developing world anyway). We need to sort our own economies first and foremost and provide a better template (with patents and copyright waived) for developing world nations for follow. Or provide them with the investment to develop new technologies themselves.
So let’s stop going on about population. It isn’t a problem and it’s just a convenient way of pushing a problem entirely of our making onto poor people who nothing to do with it. We need to be better than this.
) you have simultaneously reduced the life expectancies of Ethiopians ( 
).