Overpopulation is not the cause of global warming. Most carbon is produced through the endless consumption of the economies of Europe and the US. It is not from places with high populations.
These talking points must be fought whenever and wherever they arise.
I feel like eco-fascist talking points like this are already prevalent in liberal circles. I fully expect the majority of liberals to fully board the eco-fascist train within the next decade. Look at subreddits like r/collapse, where these ideas are basically the dominant ideology, and you’ll be gaslit if you point out that these are eco-fascist ideas.