Richard Lindzen, Professor of Meteorology at MIT appeared on NCS July 13 to discuss his position that there is no consensus that man-made CO2 increases in the atmosphere are causing global warming.  Lindzen's recent volubility on the issue is in direct response to Al Gore's publicity campaign for An Inconvenient Truth, in which Gore more or less claims that consensus exists.  Lindzen's most public expression was an op ed piece in the WSJ.  Part of the problem may be semantic: does consensus mean a majority, a plurality, or unanimity?  What seems important to me is for rational minds to listen to the explanations they hear, and draw their own conclusions.  To that end, I had Lindzen on the show knowing that his conclusions would be unpopular with the audience.  The NCS audience came through yet again: mature, open-minded, everyone I heard from appreciated hearing from Lindzen.  Some followed up in detail.  Don Patterson provided me with this substantial discussion critiquing Lindzen's ideas.  Other listeners had followup comments and one even caused Lindzen to forward an unpublished paper detailing his opinions.  In the end, I'm not persuaded by Lindzen, but I appreciate his position.  A rise in CO2 from 280 ppm to 380 ppm, the rampant reports from biologists around the world, the predictions that physics makes about warming effects, are all more persuasive to me than Lindzen's deferral that we just don't know enough and will have to wait for meteorology to grow up from its primitive state.  Proper risk analysis says we may not have that much time.