Spectral signatures of climate change in the Earth ’ s infrared spectrum between 1970 and 2006

Previously published work using satellite observations of the clear sky infrared emitted radiation by the Earth in 1970, 1997 and in 2003 showed the appearance of changes in the outgoing spectrum, which agreed with those expected from known changes in the concentrations of well-mixed greenhouse gases over this period. Thus, the greenhouse forcing of the Earth has been observed to change in response to these concentration changes. In the present work, this analysis is being extended to 2006 using the TES instrument on the AURA spacecraft. Additionally, simulated spectra have been calculated using LBLRTM with inputs from the HadGEM1 coupled model and compared to the observed satellite spectra.