Limits on CO2 Climate Forcing from Recent Temperature Data of Earth

The global atmospheric temperature anomalies of Earth reached a maximum in 1998 which has not been exceeded during the subsequent 10 years. The global anomalies are calculated from the average of climate effects occurring in the tropical and the extratropical latitude bands. El Niño/La Niña effects in the tropical band are shown to explain the 1998 maximum while variations in the background of the global anomalies largely come from climate effects in the northern extratropics. These effects do not have the signature associated with CO2 climate forcing. However, the data show a small underlying positive trend that is consistent with CO2 climate forcing with no-feedback. Department of Physics and Astronomy, University of Rochester, Rochester, NY 14627, USA Department of Atmospheric Science and Earth System Science Center, University of Alabama in Huntsville, Huntsville, AL 35899, USA