[glial]

Until the concentration is high enough it affects birth rates.

[fnordpiglet]

Birth rates isn’t what motivates people. It’s the act that creates births that people care about. To that end, until it causes impotence.

[QuarterReptile]

I hate to be the bearer of bad news, but birth rates are already pretty low, and, worse than failing to deal with the problem, some people think that is a good thing.

[jay_kyburz]

Falling birth rates _is_ a good thing and in my view its the only viable solution to global warming. Less people is less energy use and pollution.

[malka]

It might already do.