Yes of course, it's all from greenhouse gasses. In the ice ages too, while North America was like half glacier, all of siberia was open, there was a glacier around scandanavia. But the Mammoth Steppe, what they called Siberia/Eurasia there, the Steppes of Asia now, the limitless expanse of grass and fields from Ukraine to Mongolia and beyond, held an incredible diversity and amount of life for a place so far north. It actually got colder in Siberia from the ice ages, at least in the far north, what is now the permafrost, had plants and animals in the ice ages, as I understand it.
As such there is a lot of co2 trapped in organic matter up there under that permafrost, 2x as is in the atmosphere just in siberian permafrost they figure. Then huge swamps, methane sinks. The arctic is warming way faster than the rest of the world too, and as the permafrost melts that methane floods the atmosphere, (methane has been estimated to be 30% of warming so far,) and bacteria work on the organic matter in the permafrost and release that CO2, making the mother of all positive feedback loops once it gets going to that point.
It's not the total co2 that causes mass extinctions either, it's the rate of increase, if it happens slowly the earth will absorb it as it goes, when it happens too fast, it overwhelms the systems that abosorb it. A previous mass extinction also centered around Siberia, huge lava flows a thousand miles long for centuries, all absorbed in time, until one hit a giant deposit of coal and other hyrdrocarbons, and overwhelmed the co2 absorbing systems, along with all the other byproducts of coal and molten rock and burning oil. The oceans turned into toxic soup, oxygen left huge swaths of the ocean, most everything went extinct and anaerobic life made a comeback. Can't recall if that's the Permian extinction I should look up that podcast I heard on the guardian long read about it earlier this summer.
So the only thing we know for certain, is we can't know how it will play out, but that it will be faster than "expected," as monied interests make sure we expect less severe outcomes because more realistic ones would require us to change our behavior. And of course they seize on the uncertainty of it to discredit it, to do nothing, to attack. It's all rather hopeless without an organized resistance to monied interests and we don't have that, same as with politics honestly. Without good people being organized and real leadership directing them, we lose to organized monied interests that set us against each other and in the wrong directions and waste out time fighting under doomed to fail candidates and strategies.
We need to organize, it doesn't seem to matter the subject, we need to organize, and we need real leadership.