Greenland is not Melting!

The "warmers" want you to believe Greenland is melting, a sure sign of global warming gone wild. But, if you take historical data it shows that actually in the 1920's and 1930's Greenland was warmer than it is now, and there was less C02. If there was less CO2 and higher temperatures, than why do we keep hearing about CO2 driving global warming?