KARLSRUHE, Germany, July 9 (UPI) -- New research suggests that between 2008 and 2011, aerosols from volcanic eruptions were responsible for a greater amount of solar reflection than previously estimated.
In a new study, an international team of researchers point to this solar reflection as the primary reason for the momentary slowdown in global warming.
Climate scientists have spent the last several years trying to understand and explain why global temperatures over the last 15 years haven't accelerated on the same path as greenhouse gas concentrations. Increasingly, they've pointed to the role of volcanoes.
But until recently, researchers didn't have an accurate picture of the lower atmosphere's makeup, specifically in regard to volcanic aerosols. New satellite data, however, suggests these particles were twice as prolific and powerful in reflecting solar radiation as believed -- counteracting the greenhouse of effects of growing CO2 and methane concentrations.
The new lower atmosphere data was collected as part of the CARIBIC climate project, a collaboration between NASA and researchers in Europe that used airplane-mounted laser technology to measure aerosol particulates. That data was augmented by an unprecedented satellite-based analysis of aerosol and cloud layers -- an effort undertaken by researchers at NASA and France's space agency.
"The ratio of particulate sulfur to ozone from the CARIBIC measurements clearly demonstrates the strong influence from volcanism on the tropopause region," Sandra M. Andersson, a researcher and professor at the University of Lund, said in a recent press release.
Scientists say the new data reveals the significance of not just large scale eruptions, but the cumulative cooling effectives of smaller volcanoes.
"The cooling effect of volcanic eruptions was underestimated in the past, because the lowest part of the stratosphere was mostly not considered," Andersson said. "Interestingly our results show that the effect also depends on the season. The eruptions investigated by us had their strongest impact in late summer when the incoming solar radiation is still strong."
The new findings were published recently in the journal Nature Communications.