whether all the CO2 we've pumped into the atmosphere since the beginning of the Industrial Revolution has any effect on the total amount of heat being stored in the oceans and atmosphere doesn't really matter. There is plenty of evidence that the total temperature of the planet is increasing. The ice caps and glaciers are disappearing at an increasingly rapid rate.
So what if its part of a natural cycle or not. The planet has had ice ages before, and has ice free periods. But during those extreme conditions, there weren't 7 billion people on the planet. If the Antarctic and Greenland glaciers melt and the oceans rise, over a billion people will have to be relocated. Much of our most productive farm land will turn to desert. How will we feed 7 billion people with much less farmland?
Here is something to think about. If the icecaps of Greenland melt in a relatively short period of time, say 20-40 years, all that fresh cold water will be dumped into the north Atlantic, disrupting the Gulf Current. The Gulf Current is what keeps Europe warm. It could take 100 years for the Gulf Current to reestablish itself. If Greenland melts, Europe could be thrown into a deep freeze.