Ummm. Thats why for the first time ever scientists working in the arctic have discovered polar bears that have drowned. Due to the fact that there is no ice left for them to climb out on to and hunt for seals. They are raiding trash dumps in alaska because they are already straving. They have even seen cannibalism start amongst the bears, another thing they have never seen happen before.
Global warming is going to happen pretty rapidly, it already is happening. In the past 25 years about 70 species of frogs in central and south america have gone extinct because of global warming. We are on the brink of ecological collapse. The earth will be warmer then any point in the past million years if current trends continue.
The change is happening so fast that alot of species havent and wont be able to adapt.