It has been generally accepted that sunspots play or role in modern climate change, but new research suggests otherwise.
Between the years of 1645 and 1715 sunspots were scare and the winters were exceptionally harsh (a period called the "Maunder Minimum"), suggesting a link between the two phenomena, the International Astronomical Union reported.
Many scientists have argued that solar activity has been on an upward trend over the past 300 years, and it peaked in the late 20th century in what was referred to as the Modern Grand Maximum. Some have argued these factors show a link between sunspots and climate change, but there appears to be a discrepancy between two series of sunspot data.
The Wolf Sunspot Number and the Group Sunspot Number both indicate difference levels of solar activity before the year 1885 and also around 1945. This new research helps clear up the discrepancies between the two data sets, closing the data gap.
The new sunspot numbers, dubbed Sunspot Number Version 2.0, discounts the claim that a Modern Grand Maximum occurred at all. This suggests changes in the climate that spanned from the 18th century through the 20th century were not significantly influenced by solar trends. The perceived upward trend in solar activity has now been identified as a major calibration error in the Group Sunspot Number. Now that the error has been corrected, the researchers believe the data indicates solar activity has remained stable since the 1700s.
These new findings will allow existing climate models to be restructured to include more accurate data on solar activity, and could even prompt new studies in solar physics and climatology.
The findings were recently presented at the IAU XXIX General Assembly in Honolulu
