Greenhouse forcing outweighs decreasing solar radiation driving rapid temperature rise over land

Abstract

Since 1988, surface temperature over land in Europe increased three times faster than the northern hemisphere average. Here we contrast surface climatic and radiative parameters measured in central Europe over different time periods, including the extreme summer 2003, to pinpoint the role of individual radiative forcings in temperature increases. Interestingly, surface solar radiation rather decreases since 1981. Also, on an annual basis no net radiative cooling or warming is observed under changing cloud amounts. However, high correlation (rT = 0.86) to increasing temperature is found with total heating radiation at the surface, and very high correlation (rT = 0.98) with cloud-free longwave downward radiation. Preponderance of longwave downward radiative forcing suggests rapidly increasing greenhouse warming, which outweighs the decreasing solar radiation measured at the surface and drives rapid temperature increases over land. Copyright 2004 by the American Geophysical Union.