I don’t know the numbers, the thought experiment on the last point:
Imagine that without ice the ambient temperature is 5 degrees C. And that the area being ice rather than dark colored rock causes a drop of about 10 degrees C.
So the ambient temperature in the area is under 0. But as it melts for reasons then this cooling effects disappears and now the thing is basically gone forever.
Not commenting too much on the actual theory but you could easily imagine an ecosystem disappearing due to these kinds of changes
Imagine that without ice the ambient temperature is 5 degrees C. And that the area being ice rather than dark colored rock causes a drop of about 10 degrees C.
So the ambient temperature in the area is under 0. But as it melts for reasons then this cooling effects disappears and now the thing is basically gone forever.
Not commenting too much on the actual theory but you could easily imagine an ecosystem disappearing due to these kinds of changes