A post (below) on the Bishop Hill blog relating to climate change asserts that no warming effect can be attributed to CO2. I don't know whether the author is really a physicist but it sounds impressive (Plank spectra and black-body radiation etc). Can someone explain in layman's language whether the assertions are valid.
There is no greenhouse, so it can't be reversed. Many so-called skeptics are not really basing their arguments on the true physics of the atmosphere. By failing to do so, they are demonstrating that they also have fallen for the IPCC bluff that radiation from a cooler atmosphere (including so-called backradiation, but also initial radiation) can transfer thermal energy to a warmer surface. This is not correct physics and the sooner this is made clear to the public the better. True physics, backed up by basic phenomena such as the fact that radiation in a microwave oven is not absorbed in the usual sense of the word, shows why this is the case. No one has ever proved anything to the contrary in any empirical experiment, and never will. The only thing any such radiation from the atmosphere can do is slow down that third or so of surface cooling which occurs by way of radiation that does not escape to space via the atmospheric window. Radiation from the atmosphere can have absolutely no effect on evaporative cooling, chemical processes or sensible heat transfer. These non-radiative components plus the radiation to space make up about 70% of all surface cooling. Furthermore, the effect of carbon dioxide with its limited frequencies is far less than a true blackbody, and less per molecule than water vapour. No gas can radiate outside its Planck spectrum (ie more than a true blackbody) and so there is no way that carbon dioxide (1 in 2,500 molecules) can contribute a very large amount of radiation anyway. The other cooling processes merely accelerate and compensate for any minuscule slowing of radiative cooling. Thus there is absolutely no warming attributable to carbon dioxide. It is time for sceptics to get their facts right and stop giving in to part of the hoax. Only truth will prevail in the long run.
EDIT: The author of the blog post was 'Doug Cotton', who has published a related paper at http://principia-scientific.org/publications/psi_radiated_energy.pdf and has a website at http://climate-change-theory.com/