Annual sunspot activity since 1700 according to the Solar Influences Data Analysis Center (SIDC). The blue line shows annual values, red line shows the running 11-year average
. Last update: 5 February 2012.
The above chart is from from Climate 4 You
sun section web page and illustrates the trend of the sunspot number since 1700. Notice the dips that correspond to cooler periods for the global temperatures including the 1960s, 1970s:
Click source to read FULL report from P. Gosselin