Fifty Million Years
The concentration of CO2 in our atmosphere has never been higher "in history" than today - and still rising. The Guardian article talks about 50m years, this graph goes back 400,000 years and relates CO2 levels to surface temperatures:
Whether 400,000 or 50,000,000 years this is like eternity in comparison to my life, my children's lives and their children's lives - not so to the globe's age. Is it relevant? May be this makes it clearer:
400,000 years and temperature has followed CO2 levels like a shadow, which humans, in this case scientists have been able to measure in significant, rising magnitudes even during that tiny fraction of time you and I have so far spent on this globe.
It is irrelevant what you call it, (Global Warming, Climate Change) but I know, we are up for warmer periods and less ground to live on and from, unless we do something now.