Solar activity-climate relations: A different approach

The presentation of solar activity-climate relations is extended with the most recent sunspot and global temperature data series. The extension of data series shows clearly that the changes in terrestrial temperatures are related to sources different from solar activity after similar to 1985. Based on analyses of data series for the years 1850-1985 it is demonstrated that, apart from an interval of positive deviation followed by a similar negative excursion in Earth's temperatures between similar to 1923 and 1965, there is a strong correlation between solar activity and terrestrial temperatures delayed by 3 years, which complies with basic causality principles. A regression analysis between solar activity represented by the cycle-average sunspot number, SSNA, and global temperature anomalies, Delta T-A, averaged over the same interval lengths, but delayed by 3 years, provides the relation Delta T-A similar to 0.009 (+/- 0.002) SSNA. Since the largest ever observed SSNA is similar to 90 (in 1954-1965), the solar activity-related changes in global temperatures could amount to no more than +/- 0.4 degrees C over the past similar to 400 years where the sunspots have been recorded. It is demonstrated that the small amplitudes of cyclic variations in the average global temperatures over the similar to 11 year solar cycle excludes many of the various driver processes suggested in published and frequently quoted solar activity-climate relations. It is suggested that the in-cycle variations and also the longer term variations in global temperatures over the examined 135 years are mainly caused by corresponding changes in the total solar irradiance level representing the energy output from the core, but further modulated by varying energy transmission properties in the active outer regions of the Sun. (C) 2011 Elsevier Ltd. All rights reserved.