Although I have been generally on the side of the 'man made' camp I have always worried that a significant minority (I think) of scientists have had differing views. On BBC Radio 4 this afternoon a scientist gave the following info: 1) Man produces 4 billion tons of carbon dioxide each year. 2) This is only 7% of the total carbon dioxide produced each year. So far so good. The argument has been that this is too little to cause global warming. However: 3) The remaining 93% of carbon dioxide is in balance not causing an overall annual increase or decrease and the 4 billion tons is extra each year. 4) Since the start of the industrial revolution the amount of carbon dioxide in the atmosphere has risen from 260ppm to 380ppm (I think it was ppm could have been ppb, either way this is a 46% increase). Point 4 seems pretty damning. And finally a point that has been quoted to me many times: 'the amount of carbon dioxide produced by man is minuscule compared to that produced by a volcano - mount St Helens for instance'. 5) Volcanoes produce very little carbon dioxide. They produce lots of sulphides that whilst in the atmosphere actually reflect the suns rays - causing global cooling. Any thoughts anyone?