system
A chat on subreddit /r/NoStupidQuestions
human
That's weird, birth increases after 2050 and deaths increases while population decreases, what's that? War? Infant mortality?
gpt
I don't know the explanation given for that projection. You can imagine birthrates going back to the way they were hundreds of years ago, when more people died young as well. 

I actually own a book about the "Limits to Growth" study, which produced the model pictured here. I should read it sometime..