You might be referring to the Paleocene-Eocene Thermal Maximum, though the timescale for the onset of that climatic event was tens of thousands of years, not hu

You might be referring to the Paleocene-Eocene Thermal Maximum, though the timescale for the onset of that climatic event was tens of thousands of years, not hundreds. https://en.m.wikipedia.org/wiki/Paleocene%E2%80%93Eocene_Thermal_Maximum https://en.m.wikipedia.org/wiki/Paleocene%E2%80%93Eocene_The... In Our Time did an excellent podcast on it: https://www.bbc.co.uk/programmes/b08hpmmf https://www.bbc.co.uk/programmes/b08hpmmf