GEOPHYSICAL RESEARCH LETTERS, VOL. 36, L07706, 5 PP., 2009
doi:10.1029/2009GL037527
Global warming due to increasing absorbed solar radiation
Global warming due to increasing absorbed solar radiation
Kevin E. Trenberth
National Center for Atmospheric Research, Boulder, Colorado, USA
John T. Fasullo
National Center for Atmospheric Research, Boulder, Colorado, USA
Global climate models used in the Intergovernmental Panel on Climate Change (IPCC) Fourth Assessment Report (AR4) are examined for the top‐of‐atmosphere radiation changes as carbon dioxide and other greenhouse gases build up from 1950 to 2100. There is an increase in net radiation absorbed, but not in ways commonly assumed. While there is a large increase in the greenhouse effect from increasing greenhouse gases and water vapor (as a feedback), this is offset to a large degree by a decreasing greenhouse effect from reducing cloud cover and increasing radiative emissions from higher temperatures. Instead the main warming from an energy budget standpoint comes from increases in absorbed solar radiation that stem directly from the decreasing cloud amounts. These findings underscore the need to ascertain the credibility of the model changes, especially insofar as changes in clouds are concerned.
Global warming due to increasing absorbed solar radiation
this is another of those squirrelly papers that doesnt appear to make much sense if you follow it through to its natural conclusion.
somehow ghg's warm the temps and cause more humidity which lessen (???) the clouds and allow more radiation to escape (P~T^4). sounds like Lindzen's Iris Theory which was roundly criticized. these are negative feedbacks which arent stated as such. perhaps Trenberth is creating an escape hatch for when the whole CAGW edifice comes tumbling down. he wouldnt be the first.