The question about human overpopulation is not whether there can be overpopulation, but whether the often popular claim that the earth can not sustain the current or the projected future human population is true. The latter absolutely is debatable - there's no clear evidence that it's impossible (i.e. there's no technically feasible way) to sustain the current or the projected future human population. It absolutely is true that if we maintain the current level of CO2 emissions, it won't be sustainable. But that's not an evidence for overpopulation. If we sustain the current level of pollution, it likely will not be sustainable. But that's once again not an evidence for overpopulation - as we know for most of our resources that there are technical alternatives that can drastically reduce / eliminate them. We know there's more than enough energy. We know how to make our economy carbon-neutral. Most pollution can be controlled. The urban land takes up much less than 1% of the earth land - and we expect the world population to peak around 10B by 2100 (vs 7.7B today). No reason to believe we'll run out of land. There's more than enough headroom to improve the crop yields in poor countries.
In the grand scheme of things, we - humanity - know mostly how to create a sustainable technological system that can support 10B population. Whether our politics will allow us to get to such a system is a entirely different problem, and THAT might be our undoing, but I'd argue that's not really an overpopulation problem.
Also, the population growth is largely a side-effect of demographic transition - https://populationeducation.org/what-demographic-transition-.... i.e. it's a transitional side-effect of reducing the human suffering. The only humane and equitable way to move forward is to accelerate the demographic transition (i.e. improve the economic, health, education, etc, systems of all countries in the world to get them to stage4 at least). And, thus, "keep our numbers down" is not only inhumane or inequitable, that's ineffective - the developed countries already mostly stopped growing - e.g. https://www.statista.com/statistics/1251591/population-growt... - and it's mostly the poor countries that are growing - i.e. https://www.statista.com/statistics/264687/countries-with-th... . There's no other humane way to stop poor countries' population growth - the most effective way is to improve their economy, improve their health and healthcare systems, and improve education.
"The question about human overpopulation is not whether there can be overpopulation, but whether the often popular claim that the earth can not sustain the current or the projected future human population is true"
So only human overpopulation is impossible, you're saying. I think you're wrong on that. We're special relative to other species -- but not that special, and not immune to it.
"In the grand scheme of things, we - humanity - know mostly how to create a sustainable technological system that can support 10B population. Whether our politics will allow us to get to such a system is a entirely different problem, and THAT might be our undoing, but I'd argue that's not really an overpopulation problem."
Is the goal to pack as many humans onto this planet as is possible?? That certainly isn't my goal, at all. With our technology, we don't need vast numbers with which to build pyramids or plant fields.
> So only human overpopulation is impossible, you're saying.
No. That is not what I said. I'm saying whether human overpopulation is theoretically possible/impossible is not the question - as the answer is very clearly yes, if the number is too large it will qualify as overpopulation.
I'm saying the relevant question is whether the current population and the projected future population would qualify as overpopulation, and I'm saying that absolutely is debatable.
> Is the goal to pack as many humans onto this planet as is possible?
No. The goal is to find the humane and equitable way to reach sustainability. I'm claiming sustainability (with current or projected peak human population of ~10B) is entirely technologically possible, and "overpopulation" talk is mostly ungrounded, not backed by any real evidence. At the same time, it's also clear the current state of things is NOT sustainable, and that we'd need to change our technological systems in order to reach sustainability, and I do admit that it's entirely possible and somewhat plausible that our politics will keep us from reaching the sustainability.
In the grand scheme of things, we - humanity - know mostly how to create a sustainable technological system that can support 10B population. Whether our politics will allow us to get to such a system is a entirely different problem, and THAT might be our undoing, but I'd argue that's not really an overpopulation problem.
Also, the population growth is largely a side-effect of demographic transition - https://populationeducation.org/what-demographic-transition-.... i.e. it's a transitional side-effect of reducing the human suffering. The only humane and equitable way to move forward is to accelerate the demographic transition (i.e. improve the economic, health, education, etc, systems of all countries in the world to get them to stage4 at least). And, thus, "keep our numbers down" is not only inhumane or inequitable, that's ineffective - the developed countries already mostly stopped growing - e.g. https://www.statista.com/statistics/1251591/population-growt... - and it's mostly the poor countries that are growing - i.e. https://www.statista.com/statistics/264687/countries-with-th... . There's no other humane way to stop poor countries' population growth - the most effective way is to improve their economy, improve their health and healthcare systems, and improve education.