The threat of global warming just became a little bit too real.

A working paper from the National Bureau of Economic Research says climate change — to quote the Bloomberg headline I saw — kills the mood.

Economists studied 80 years of fertility data, cross-indexed it with temperature data, and lo and behold: when there are more days than usual above 80 degrees, there’s a drop in, quote, “coital frequency,” and thus a drop in births 9 months later.

More to the point: even if it cools down, you never get those extra births back.

Who said climate change policy isn’t sexy?