The most credible sources are the "grunts" working on the front lines of research -- drilling the ice cores, taking the measurements, crunching the data, and publishing their findings. Their loudest critics are talking heads, desk jockeys and radio hosts who take "pot shots" at research but have never done it themselves.
Notes: Variation: They wcouldn't know an ice core from a "Sno Cone"
Bite Source: Tom Smerling
Image Source: here