The report claims “Multiple lines of independent evidence confirm that human activities are the primary cause of the global warming of the past 50 years.”
So I decided to download the report to see what the “evidence” was. You can download the full report (36Mb) here: NCA3_Climate_Change_Impacts_in_the_United States_LowRes.pdf
The bottom line of my analysis: NCA presents no unequivocal evidence that supports their contention of significant human induced warming.
You can read my analysis on my blog here:
http://wryheat.wordpress.com/2014/11/15/national-climate-assessment-lacks-physical-evidence/
See also:
UN IPCC Synthesis Report is a pack of lies