[timschmidt]

> look up any random day and see a meteor streaking across the sky

That's happened rather more times in Earth's history than most folks are comfortable admitting. Tunguska would have leveled any major metropolitan city on the planet. I still think an impact is one of the more likely initiators of the Younger Dryas abrupt cooling and worldwide ~100M sealevel rise ~12,000 years ago. Conspicuously aligned with the oldest surviving traces of city living, agriculture, etc. It's increasingly accepted that a large portion of human history is 100M underwater on the continental shelves, estuaries, and other coastal areas where humans would have liked to live.

[macartain]

It's increasingly accepted that a large portion of human history is 100M underwater on the continental shelves, estuaries, and other coastal areas where humans would have liked to live.

Any references for that? Genuine question.

[timschmidt]

Here's a review: https://www.sciencedirect.com/science/article/abs/pii/S02773...

More:

https://www.pnas.org/doi/10.1073/pnas.1411762111

https://www.nature.com/articles/s41586-025-08769-7

https://www.academia.edu/9737879/Land_Beneath_the_Waves_Subm...

https://pure.york.ac.uk/portal/en/publications/under-the-sea...

[macartain]

Much appreciated - living in the UK, I have heard of Doggerland and should have expected there would be plenty of similar areas worldwide - this is interesting stuff.

[timschmidt]

It's really amazing how much more connected the world was not very long ago. Take a look at 24k years ago here: https://sea-level.vercel.app/ Nearly every continent is one connected landmass. And all the most prime real estate is now under water.

[mjhay]

The impact hypothesis for Younger Dryas isn’t really tenable. Among other things, the climate effects of a large bolide impact would be global, whereas Antarctica actually warmed during YD. This “Polar See-saw” pattern is easily explained by a northerly meltwater pulse hypothesis, but not a bolide.

[vkou]

Sea level rise was much faster before the cooling of the Younger Dryas.

[timschmidt]

You're right, and here's a graph: https://en.wikipedia.org/wiki/Past_sea_level#/media/File:Pos...

It's possible the sea level rise could have initiated the cooling. But there is much disagreement as to what exactly initiated the de-glaciation which caused the sealevel rise.