LONDON, Oct. 6 (UPI) — The sun’s activity has recently affected the Earth’s atmosphere and climate in unexpected, unpredictable ways, U.K. and U.S. researchers say.
Researchers from Imperial College London and the University of Colorado found that a decline in solar activity does not always mean the Earth becomes cooler.
It is well known the sun’s activity increases and decreases in an 11-year cycle, and the study of activity from 2004 to 2007, when the sun was in a declining part of its cycle, yielded the unexpected result, an Imperial College release said.
Contrary to expectations, the amount of energy reaching the Earth at visible wavelengths increased rather than decreased as the sun’s overall activity declined, causing a warming effect, researchers said.
After this surprising finding, researchers say they believe it is possible the reverse is true and periods of increasing overall activity on the sun tend to cool, rather than warm, the Earth.
“These results are challenging what we thought we knew about the sun’s effect on our climate,” said Professor Joanna Haigh, head of the Department of Physics and member of the Grantham Institute for Climate Change at Imperial College London.
“However, they only show us a snapshot of the sun’s activity and its behavior over the three years of our study could be an anomaly.
“We cannot jump to any conclusions based on what we have found during this comparatively short period.”
“However, if further studies find the same pattern over a longer period of time, this could suggest that we may have overestimated the sun’s role in warming the planet, rather than underestimating it.”
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