Great answer.
But i am not convinced (please note: I am not questioning the existence of man made global warming).
1. The deforestation has been going on for ages and it continues with far greater pace than the global warming and it is unrelated to the GW.
2. Overfishing has put many spices on the verge of extinction, and it is again unrelated to GW.
3. Habitat destruction for agriculture is threatening not only wild animals but whole ecosystems and again is unrelated to the GW.
4. The Great Pacific garbage patch is as big as Texas (that is the lowest estimate), again unrelated to GW.
So, why are we so fixated on the global warming alone as if it is the cause of all the eco-problems?? Could it be because it threatens those private islands and beach houses where the wealthy live??
P.S. not really millions of years: the LGM was around 24 000 years ago and the Younger Dryas was even later. So at least the Northern Hemisphere experienced several radical climatic changes fairly recently.
Thank you. The issues you brought up, except for habitat destruction (the polar bear is an obvious example here), are largely not very related to global warming either, I would say red herrings. But when you quickly change the climate, you change the local conditions all kinds of organisms around the world have adapted to, which will cause trouble for a lot of species that can't live under the new local conditions, causing habitat destruction. But take for example the oceans getting more acidic as CO
2 is dissolved in the oceans, damaging coral reefs, or the sea level rise damaging low-lying areas (you seem to acknowledge it threatens the private islands and beach houses where the wealthy live, but that's not all that is along the coast, we have millions of people living in cities along the coasts, including Copenhagen where I go to every other day, which also needs to spend huge amounts of money on upgrading its sewers and infrastructure to cope with the increased amounts of rain we risk getting during the summer), the more extreme weather increasing the probability of many natural disasters such as hurricanes, floods and drought depending on the area.
Global warming isn't the only big ecological problem for humanity or the cause for all ecological problems, but it definitely is a big problem with a lot of negative consequences.