Well that's actually not very accurate. Climate science might be fairly new but we do know about why longterm changes occur because of plate tectonics; we know that the continents are currently separated about as far as they're going to be and that shortly, on a geological timescale, they will stop separating and start to come together again; the supercontinent cycle theory is well-supported by evidence. But the change we're concerned about here is not due to geochemistry or plate tectonics, like the paleoclimates you, ah, study. It's due to human activity; it's the principle cause of the observed instabilities in ice sheets and glaciers. If the Thwaites glacier collapses, the theory says much of the ice behind it will follow it into the Southern Ocean, eventually. Oops.
Yep. A big meteor or massive volcanic activity will do that. Still, perhaps it is best to not try to force the climate to change that fast, since past changes have caused massive extinctions. Even if that SUV has a really nice ride.
Of course, the effect from meteors and volcanic activity was to produce rapid cooling, loss of crops/food, etc which were indeed deadly. It seems most likely that a series of bolide impacts may have initiated the younger dryas cold snap, during which, it seems that north american megafauna and the people of the clovis culture died off. From the archaeology record, I do not know of any sudden warming event that was harmful to life on this planet. Some have theorized that the people and megafauna were killed by the bolide impacts themselves, while others contend that it was the sudden cold snap.
