Peter🌲Brannen

@peterbrannen1 · Twitter · 2026-03-21 15:30 UTC

Need to gently push back on this as a paleo guy, it's possible we've passed CO2 levels of the mid-Pliocene ~3 million years ago, but probably not of the middle Miocene ~16 million years ago. Still very worrying: middle Miocene CO2 was 450-550ppm and the planet was 7-8°C warmer(!)