The domino effect predicted that once the CAGW hypothesis began to unwind new papers would come thick and fast and bury the idea in a terminal fashion. We might ask is this now happening as following close on the heels of the paper by Professor Roy Spencer we have this story at http://joannenova.com.au/2011/08/blockbuster-planetary-temperature-contr… which is a report on a speech by Professor Murry Salby at the Sydney Instiitute, 'Global emissions of carbon dioxide: the contributions from natural sources. This is being touted as very important as he is Chair of Climate Science at Maquarie University, one of the big guns. Basically, he has been looking at C12 and C13 ratios and co2 levels around the world and has reached the conclusion that man-made emissions have only a small effect on global c02 levels. A podcast is available to download and listen to his talk (see also Judith Curry's post at Climate Etc, http://judithcurry.com/2011/08/04/carbon-cycle-questions/ and the many comments that follow). However, a paper itself it not due to be published for another 6 weeks. Indeed, Salby seems to have been sitting on his research for months unsure how to proceed with it as it went against his previous stance on AGW. A book is expected to be published by the end of the year, 'Physics of the Atmosphere and Climate' which will form opinion as Salby is somebody with clout and other scientists in other disciplines will listen to what he says (or so it goes). Salby will not easily be dismissed by 'The Team' unlike Tom Quirk who came out with something along the same lines but was largely ignored. It seems that EM Smith has also played around with the same idea, see http://chiefio.wordpress.com/2009/02/25/the-trouble-with-c12-c13-ratios/ after he took issue with the belief of climate scientists such as Michael Mann that plant based carbon gets into the atmosphere by people burning fossil fuels, on the basis that oil and coal have a plant origin. It seems there are a lot of unproven assumptions about climate science and yet the CAGW crowd are convinced they are right and everyone else has to accept what they say. EM Smith, it is true, just toys around with the idea, but he is retired and playful, one might say, but he managed to pre-empt Salby by a couple of years.
PS … Judith Curry notes that Salby is author of 'Fundamentals of Atmospheric Physics' which is a teaching tool in universities. He is both a respected lecturer and a teacher and has a reputation for being a thorough and careful researcher.