Sure, correlation is not causation, but it is causation if there’s independent physical evidence that there is a link. And we have plenty of that.

Much of the doubt and discussion these days is about attribution of surface warming to human causes, specifically human fossil fuel emissions. It can be done in many ways, the most scientifically convincing being ratios of isotopes of carbon and oxygen in excess CO₂ in atmosphere, and in remaining atmospheric composition. But there’s a more direct way, and I offer that below.

This is a plot of the GLBSSST temperature anomaly series I was using as the baseline for the two guest posts I did at The Azimuth Project blog, with the second being here. The temperature anomalies are with respect to a 1950-1980 baseline, in degrees Celsius, from 1880. Displayed atop it in red is the scaled and shifted value for global CO₂ emissions by just humans from all sources.

(Click on picture to see larger image.)

That’s pretty damn convincing.

Addendum, 4^th July 2014, 2107 ET

I did a plot to counter a claim that atmospheric CO₂ concentrations don’t correlate with (human) fossil fuel emissions. Seemed to fit well here.

(Click on picture to see larger image.)