Anthropogenic greenhouse forcing and strong water vapor feedback increase temperature in Europe -: art. no. L19809

Europe's temperature increases considerably faster than the northern hemisphere average. Detailed month- by-month analyses show temperature and humidity changes for individual months that are similar for all Europe, indicating large- scale weather patterns uniformly influencing temperature. However, superimposed to these changes a strong west- east gradient is observed for all months. The gradual temperature and humidity increases from west to east are not related to circulation but must be due to non- uniform water vapour feedback. Surface radiation measurements in central Europe manifest anthropogenic greenhouse forcing and strong water vapor feedback, enhancing the forcing and temperature rise by about a factor of three. Solar radiation decreases and changing cloud amounts show small net radiative effects. However, high correlation of increasing cloud- free longwave downward radiation with temperature ( r = 0.99) and absolute humidity ( r = 0.89), and high correlation between ERA- 40 integrated water vapor and CRU surface temperature changes ( r = 0.84), demonstrates greenhouse forcing with strong water vapor feedback.