Incredibly misleading quote of the paper:

Managing populations is equally intractable. In many countries, calling for population planning would constitute political suicide. Even the United Nations Population Fund recently ‘decried any expressed concern about population growth as “alarmist”’ (O’Sullivan 2022b); strong advocates of population reduction strategies policies risk being vilified as racist, eco-fascists, eugenicists, anti-human or worse.

Hey look, I spotted the one part where it mentions anything having to do with eugenics.

That's not the author discounting a eugenic solution, just admitting that a population cull would be practically impossible. The rest of the paragraph:

Such attitudes and accusations are yet another manifestation of innate reductionist simplicity exacerbated by socially-constructed ideological blinders. Bajaj (2022) argues that the UN’s taunt of population alarmism springs from widespread pro-natalist ideology ‘which results in unrelenting pressures – a globally pervasive form of reproductive coercion – experienced primarily by women’. She further emphasises that that ‘pronatalism is integral to our current growth-based economic system, which relies on constant population growth to supply new consumers continually’. Indeed, corporations in the US [and other countries experiencing ‘peak population’] are sensationalising the idea of an economic ‘baby bust’ that threatens the nation with a paucity of workers, a reduced tax base and the loss of international economic clout. Many governments are responding with incentives to increase national fecundity.

The author urges the initiation of a global depopulation project led by the UN, using what seems to be geopolitics academic jargon for "starve people, start with the poor countries."