Afraid I'm not convinced, Bart. There are two things wrong with this if you're saying it indicts CO2 as a culprit.
First, I don't know what the source of the data is. All it says is "Hemispheric Temperate Change." Who says so, and on what basis? We don't even know what the thing purports to measure. There's no magnitude scale. It could be measuring degrees centigrade, degrees Fahrenheit, or tiny fractions of either, or neither. Maybe the whole thing shows an increase of 1/1000 degree over 120 years. I easily can cook up a graph that shows just the opposite and call it Hemispheric Cooling.
Secondly, if the chart tells me what you claim it does, and I'm not convinced it does, who's to say this isn't one of those long-term trends we saw in the 900's? The thing covers 120 years. To jump to a correlation with CO2 levels is quite a jump. But even if there were such a correlation, remember this basic fact about statistics: "Correlation is not causation." Everybody pushing the global warming "trend" seems to have forgotten that.