Like these shifts in climate, you see fluctuations throughout time in birthrates and death rates. Japan is quite land locked, and highly populated. I content that God or what ever a person believes established a causal system that regulates this naturally. Our mistake is we go into wars, and some become murderers. A little gay isn't so bad in that sense.
If this author really cared about boosting white populations, he and his wife should have had several kids and they should have demanded nuns and priests do the same. Instead, the author hypocritically and selfishly has ZERO kids. Wonder how many abortions are in his closet?