Comments by "Old Scientist" (@OldScientist) on "PBS Eons" channel.

Warming events in the Cenozoic do not correlate to mass extinction, whether the warming is correlated to CO2 or not. The Paleocene-Eocene Thermal Maximum PETM (55mya), a time when the Earth warmed rapidly to temperatures far in excess of today's, only resulted in a noticeable extinction of some benthic foraminifera. That was so small of an event it doesn't even show up on a marine extinction intensity chart for the Phanerozoic. There was, in fact, a more general flourishing of life at that point, especially terrestrial. Many major mammal groups appeared and spread around the globe including hyaenodontids, artiodactyls, perissodactyls, and primates. So if the Earth is warming, we've got that to look forward to. The next largest extinction event, since the dinosaurs bit the big one, is the Eocene-Oligocene transition ("Grande Coupure" = The Great Rupture). This seems to have been connected with cooling (rapid Antarctic glaciation), not warming. If i can quote from a paper by Aze (2022) "the PETM is not classified as a mass extinction event, as significant levels of extinction are limited to just a handful of taxonomic groups, and overall extinction rates do not increase beyond background levels".
2
@bobbobby3085 It has warmed faster in the recent and distant past.
1
@bobbobby3085 The big problem for doomists is peak interglacial warmth is not now but around 8,000 years ago. Proxies show a downward trend to the present day but with an interruption for the Medieval Warm Period (that doomists aren't allowed to believe in) followed by a decent into the The Little Ice Age (which doomists think also didn't exist), and a very slight recovery to the present day still below MWP though. So there is supposed rapid warming over the last century but that's not a fair comparison with previous ages. That's instrumental - which has its own reliability issues due to it poor spatial and temporally collection (until the advent of satellites) - with annual instrumental measurements compared with proxy data with the latter's resolution intervals often at 200 years. If we smooth out the current data over the last two centuries you'd be lucky to see ½ degree per century. Your rapid warming disappears, and a very large number of bicentennial periods over the last 16,500 years warm at a faster rate (than 0.5°C/century). And let's not forget the Dansgaard–Oeschger events. The Dansgaard–Oeschger events were global (Dima et al, 2018). One about 11,500 years ago, averaged annual temperatures on the Greenland ice sheet increased by around 8°C over 40 years, in three steps of five years, but a 5 °C change over 30–40 years is more common for these events. So shall we say a rate of change about 20°C per century? If that happened now people would assume the Rapture was imminent. But life carried on.
1