The letter debunks a Jan. 27, 2012 op-ed piece from 16 "scientists" repeating the usual denialist myths (the earth isn't warming, etc.). But only 4 of the 16 have ever published peer-reviewed reports on climate, while 6 have close ties to the fossil fuel industry. For more about the 16 "scientists" see Media Matters.
Source: Wall Street Journal, Feb. 1, 2012
"Do you consult your dentist about your heart condition? In science, as in any area, reputations are based on knowledge and expertise in a field and on published, peer-reviewed work. If you need surgery, you want a highly experienced expert in the field who has done a large number of the proposed operations."