In each case, they found significant temperature deviations during years in which disturbances occurred. (sciencedaily.com)
Annual Global Temperature Deviations in the Troposphere and Low Stratosphere, 1958 - 2004 February 2005 Source: J. K. Angell Air Resources Laboratory National Oceanic and Atmospheric Administration Deviation of yearly temperature from the 20 - year average, 1958 - 1977 (junksciencearchive.com)
Backing that up, NASA says that 1) sea surface temperature fluctuations (El Niño - La Niña) can cause global temperature deviation of about 0.2 °C; 2) solar maximums and minimums produce variations of only 0.1 °C, warmer or cooler; 3) aerosols from natural sources such as volcanic eruptions (Mount Pinatubo for example) have caused average cooling of 0.3 °C, but recent eruptions have had not had significant effect. (treehugger.com)