"In terms of the last 30 years I'd have to agree that there's nothing in these records that suggests solar variability could be giving rise to warming global temperatures," said Carl Wunsch, a climate expert at the Massachusetts Institute of Technology in Cambridge, who was not involved in the study.
"Nobody can show that there is no solar/Earth climate connection," he added. "But having said that, if there is one and if these records are representative, whatever connection exists is weak."
In the latest study, co-author Lockwood does report evidence for a past solar role in shaping Earth's preindustrial climate.
"I even believe that you can detect in the climate record a solar influence up until about 1940," he said.
"The trouble is that [in] about 1960 solar variability started to become dominated by fossil fuel burning and greenhouse gases."
Gavin Schmidt, climate scientist at NASA's Goddard Institute for Space Studies and an editor of the blog www.realclimate.org, agreed.
"Basically, there simply isn't a trend in solar activity that would explain the rapid warming that has occurred in recent decades," said Schmidt, who was unaffiliated with the study.
That isn't to say that there isn't a solar influence on climate change in the past, or that there isn't still uncertainty in possible mechanisms, he added.
"But for what we are concerned about now, the sun is not too blame.
"Think of the sun as a criminal suspect who has a long record, but a cast iron alibi for the latest crime," Schmidt said.
"And meanwhile, the fingerprints of CO2 are all over the murder weapon."
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