Global Warming Myth?

Is man-made Global Warming a myth - or is it science?
I'm not sure either way.

If the Earth is warming and melting it's Polar caps - what would one expect to happen?
Would the Earth warm or would it cool?
A simple experiment would be to place a few ice cubes in a glass of water and then to set the glass on a counter.
As the ice melts from the warmer environment - the ice cools the water and the water warms the ice until an equilibrium is met.
After the energy from the ice is spent, the water will continue to warm in a warm environment.
(But the Universe is cool so one should expect another Ice-Age after many of us die out.)
Is this what we should expect if the Earth continues to warm - a planet filled with lukewarm water which floods most of our coastal cities displacing most of the world's occupants?
Maybe this isn't such a bad thing after all.
Maybe this flooding will act as a strong bacteriophage and kill off many of those who act as a virus to the planet.

If this is the case and we fail to head the warnings - blame science.
Science had a strong case but someone decided to tamper with the evidence.
Science is the overanxious cop who plants evidence on a guilty suspect because he wishes for the guilty party to be punished.
But what happens when such tampering is discovered?
Isn't the evidence thrown out the guilty party usually set free?
Doesn't society suffer from such an act and not the cop nor the criminal?