What about in the days of coal fires and the industrial revolution? Surely we were poluting the atmosphere a tad then? Is there any actual evidence?

Don't you get the point? It's when we started using fossil fuels that the atmospheric carbon dioxide started to grow. As you'll see from this graph (careful reading it, dates at the LEFT are later), carbon dioxide has been increasing rapidly since the Industrial Revolution. It was measured in 2005at 379ppm. This compares to a pre-industrial level of 278 ppm, and a range over the previous 650,000 years of between 180 and 300 ppm, according to the Intergovernmental Panel on Climate Change (IPCC).

The other thing to remember is that the world's population pre- industrial revolution was only about a tenth of todays, so a lot more people are contributing.