Should the Human Race Fear Climatic Change?

As far as the climate is concerned, the human race has been fortunate to enjoy friendly temperatures ever since we can remember.
We have surely had our fair share of natural disasters, and these alone constitute a certain degree of fear in our conciousness.
So what if one day we have the oceans rising, as to gulp down the islands and indeed the many ports and harbours?
What if one day the Ultraviolet rays pierce through the atmosphere and give us a plethora of yet unknown skin diseases?
What if the already shrinking supply of fresh water becomes unreachable for more than ...