"NASA has studied this extensively"  More BS nonsense.  They "study" it with computer models.  The are NOT evidence.  Besides, assume it is true, a cooler cycle is a bad cycle.  Crops fail.  People starve,  So if that is true, we saved humanity by pumping CO2 and warming the planet.  

But of course it is not true.  Short of going back in time, removing humans, and watching what the planet "should have done" can they possibly know what should have happened.

BTW, the IPCC says the first half of the 21st century warming was natural.  Read the last paragraph.  
http://www.ipcc.ch/publications_and_data/ar4/wg1/en/ch9s9-4-1-5.html