I don't think photosynthesis "just adapts", it evolves quite slowly (if it could evolve faster, it would be much more efficient!).

Also, your geological timelines are way off. Last interglacial period (with temperatures higher than today) was 100k years ago.

HN has literally became an anti-intellectual echo-chamber.

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kzrdude 20 hours ago | parent [-]

The last million years had comparable temperatures, you'd need to go back to 50 Myr ago to have a significantly warmer climate, and without inland glaciation anywhere on Earth.

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tomp 19 hours ago | parent [-]

I’ll trust Wikipedia on this topic.

> The Last Interglacial climate is believed to have been warmer than the current Holocene.

> During the northern summer, temperatures in the Arctic region were about 2–4 °C higher than in 2011

https://en.wikipedia.org/wiki/Last_Interglacial

	▲	kzrdude 17 hours ago \| parent [-]
		I think that misses the point (or at least my point). Yes it was warmer then. But it was even warmer 50 Myr ago. For example one thing that sets the two periods we are discussing apart was if Antarctica had glaciers at all or not. The Climate heading in this article will give a little overview https://en.wikipedia.org/wiki/Cenozoic See also the plot here https://en.wikipedia.org/wiki/Paleocene%E2%80%93Eocene_Therm...