Population Collapse vs Population Adjustment

 A friend send this alarmist screed on declining birth rates in USA.

I replied:

"Population collapse" is not what happens when birth rates decline but remain above 0.5 children per couple.  That's "population adjustment" which can help curb carbon emissions, water depletion, and other looming catastrophes.

"Population collapse" is what happens when we fail to do population adjustment fast enough, and central North American becomes useless for human agriculture and settlement.