The European solar radiation sensor net monitored and compared data from 1989 to 2012 with data from 1965 to 1988:
Mitteleuropa: Das Geheimnis des roten Sonnenflecks - SPIEGEL ONLINE - Wissenschaft
One climate "scientist" Blanka Bartók (as if there were such a science) explains the +3.21 W/m^2...