kikobar, (edited ) 
I don't understand why this is considered an existential risk, with governments spending fortunes to 'fix the low birth rate problem'.
I believe it is good news.
We are clearly a species that needs to reduce its footprint on Earth. There is nothing sustainable about our ever-growing population.
Only in a distorted fantasy worldview of perpetual growth without negative consequences the low birth rate could be a concern.
https://www.bbc.com/news/world-asia-68402139?utm_source=press.coop