New book finds at least 63% of global warming was due to the Sun — ‘Authors predict a decrease in solar activity during 21st century will result in global cooling of 0.64ºC over next 100 years’
Published in 2012: 'Finds that at least 63% of the global warming of the past 400 years was due to an increase in solar activity. According to the authors, 'The sudden increases of solar activity that occurred after the 1724 and 1924 solar dynamo transitions have been accompanied by sudden increases of average surface temperature of 0.2ºC and 0.34ºC after 1974 and 1924, respectively'
Therefore, out of the total increase in global temperature of ~ 0.8ºC during the past 400 years, less than 0.3ºC may be of non-solar origin, in agreement with previous results.” The authors predict a decrease in solar activity during the 21st century will result in global cooling of 0.64ºC over the next 100 years.