I respectfully suggest you examine the onset of the Eemian, the last interglacial period, about 130k years ago. Global temperature abruptly rose by more than 5

I respectfully suggest you examine the onset of the Eemian, the last interglacial period, about 130k years ago. Global temperature abruptly rose by more than 5 degrees Celsius in just a few centuries. That was not the most sudden warming we know of, and its speed was not a tiny fraction of the current warming speed.