A quote: "I have absolutely no interest in attempting to persuade anyone of this conjecture being either true or false."
Be that as it may, you may want to think about how people respond to a rational appraisal of our present circumstances. Remember that evolution and natural selection are at work in the modern world, in human society. So, given that, your audience can be segmented into two groups:
* First, those who are intelligent, compassionate and responsible enough to take remedial action, i.e. stop having children. What? You thought there was some other solution to the looming environmental catastrophe? There isn't -- the relentless mathematics of population increase cannot be bargained with or ignored.
* Second, those who are not intelligent, compassionate or responsible enough will more than make up for the actions of the above class of people by creating the entire future human species. The result is that, as things on Planet Earth get worse, the intelligence and perceptiveness of the survivors will continue to fall.
The above is the simple version of present reality, but it cannot be used to rationalize eugenic or racist policies. We're all in this together and the problem is not which children, it's the fact that there are too many people -- of all kinds -- having children without thinking.
We're victims of our own biological success, and it appears nature has a sick sense of humor.
Author sounds like an extrapolating drama queen. Humanity adapts, as does life.