CO2 Sanity

Not too long ago a post at WUWT examined the most often-used data set for atmospheric CO₂ concentration, from the Mauna Loa atmospheric observatory. The post itself is just a curve-fitting exercise, but the author doesn’t make outlandish claims about the significance of his conclusions. What’s disturbing is some of the reader comments, especially from those who don’t want to believe that the CO₂ increase has been caused by human beings.