@breadandcircuses
Two of the (many) things that keep me up at night:
decreased glaciers leading to increased tectonic/volcanic activity (and accompanying particulate and gaseous releases), and
the massive feedback loop of methane and CO2 from melting permafrost and subsurface carbonate.

I have daymares about the Earth turning into another Venus... 🫣😅

https://www.pnas.org/doi/10.1073/pnas.2107632118

https://cleantechnica.com/2018/04/28/the-tectonic-volcanic-events-that-will-accompany-the-melting-of-the-ice-sheets-an-overview/