A new study has shown that particles released into the air during volcanic eruptions reflected sunlight, altering temperatures to drop. The recent spate of volcanic eruptions, particularly those in Indonesia, may have caused massive damages but on a global scale, such nature's wrath has done more good than harm to the world's rising mean temperatures.
While scientists claimed temperatures have risen since the start of the century, they were far below compared to the rise in man-made greenhouse gases.
Earlier, scientists surmised the particles released to the air during volcanic eruptions would trigger temperatures worldwide to further escalate from 1998. But they noted the reverse occured.
"This is a complex detective story," Benjamin Santer, lead author of the study, "Volcanic Contribution to Decadal Changes in Tropospheric Temperature" published in the journal Natural Geoscience, said.
But while volcanoes may be part of the answer, "there's no factor that is solely responsible for the hiatus" of global warming, he told Reuters.
The study said volcanoes contributed 15 percent of the difference between forecast and actual warming in the present century. Eruptions such as that of the Philippines' Mt. Pinatubo in 1991 had actually dimmed out global sunshine.
The researchers said albeit sulfuric, the particles spewed by the volcanoes reflected sunlight and slightly cool the lower atmosphere.
But researchers were quick to point there could be other reasons for the warming "hiatus," such as a decline in the sun's output, or China's rising emissions of sun-blocking pollution.
But the benefits of such volcanic eruptions would remain temporary.
"Volcanoes give us only a temporary respite from the relentless warming pressure of continued increases in carbon dioxide," Prof. Piers Forster of Climate Change at the University of Leeds said.
"We do not know how volcanic activity will evolve over the coming decades, and thus we do not know how long our luck will continue," Santer said. The level of carbon dioxide in the atmosphere in 2013 had already crossed the threshold of 400 ppm.
Scientists confirmed carbon dioxide concentrations will continue to expand at 2 ppm or 3 ppm per year, driven by the coal burning activities of emerging economies.
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