How Credible Is NASA on Climate Change?

The following web page on the NASA website http://climate.nasa.gov/scientific-consensusstates

Ninety-seven percent of climate scientists agree that climate-warming trends over the past century are very likely due to human activities,1and most of the leading scientific organizations worldwide have issued public statements endorsing this position. The following is a partial list of these organizations, along with links to their published statements and a selection of related resources.

On this same page, near the bottom, the following statement is found

The following page lists the nearly 200 worldwide scientific organizations that hold the position that climate change has been caused by human action. http://opr.ca.gov/s_listoforganizations.php

I can list the studies that have repeatedly debunked the 97% figure (aka a lie).  However, it's more telling just to examine this last claim.  Did NASA somehow miss the last several periods of worldwide glaciation (climate change in its most severe form) that occurred before humans occupied the planet? 

For more about the intentional misrepresentation on the climate consensus "google" The Myth of the Climate Change '97%' in order to see the whole Wall Street Journal, May 26, 2014 article
http://online.wsj.com/news/articles/SB10001424052702303480304579578462813553136