Ya ice sheets diminish, so what. It has done so since the beginning of time and will until the end of the planet. Ever heard of an ice age? Why did the ice retreat??? I don't think there were any evil SUV's at that time to cause all the ice retreating. Use some common sense. The earths climate ebs and flows and we have little of nothing to do with any of it.
In localized ecosystems we can affect, but not the whole of it.

Hell, we can't ever predict the weather accurately next week. Why would you trust anyone saying they can predict the entire planets future. hahaha. what a joke.