CO2 exonerated yet again

A study done near the Greenland Summit camp at the peak of the Greenland ice sheet using "argon and nitrogen isotopic ratios from occluded air bubbles"  suggests that current snow temperatures in Greenland are within the range of natural variability experienced in Greenland over the last 4000 years. Remember when the Norse were in southern Greenland?


The authors concluded:


What it means
Clearly, there is nothing unusual, unnatural or unprecedented about Greenland's recent relative warmth, as it is clear that much warmer temperatures have been experienced there over many prior prolonged periods without any help from anthropogenic greenhouse gas emissions. Hence, there is no valid reason to believe that mankind's burning of coal, gas and oil has had, or is having, any measurable impact on the climate of that part of the world, or any other part of the planet.


As it so happens this year ( March 2012)  the ice around Greenland is greater than that in 1979. 


Is this why Hansen is doctoring the temperature data in Greenland?

CO2 exonerated.