Some people say, "why worry about climate change?" "The climate is changing anyway."
Over 13,000 years ago, Seattle was under 10,000 ft of ice. Of course, Seattle wasn't there back then. 13,000 years is much farther back than all of recorded history.
The global warming worry is about the next 100 years. Can we make it through the next 100 years? Our kids and grand kids. That's an important question for civilization. After that, who knows. Maybe we will be building huge colonies in the solar system by then; if civilization survives.
It's the next century that's the time scale for global warming worry, as far as civilization goes. As for other species of plants and animals, yes, they have come and gone. Many have gone extinct over the millions of years before we were here to care.