When is an increase of half a million tons per year of CO2 insignificant?

A project that adds the equivalent of 17 new sources under ARB's Cap and Trade rules isn't significant, according to the SJVAPCD. Read why here:

http://www.examiner.com/environmental-news-in-bakersfield/when-is-an-increase-of-half-a-million-tons-per-year-of-co2-insignificant