The role of volcanoes as climate coolers

07-03-2018 LucaOZ
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A comprehensive study published in the journal Nature, has found new evidence of the correlation between climate and volcanic eruptions over the past 2,500 years changes. Conducted by the Desert Research Institute and various international institutions has primarily been collating the presence of particles of volcanic sulphate in the deep ice of Antarctica and Greenland with sudden drops in temperature that left its mark in historical documents and changes thickness of tree rings.

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Thus, for example, it has been found that 15 of the 16 coldest summers on record between 500 BC and 1000 AD were preceded by large eruptions, whose clouds of dust clouded the atmosphere and dimmed the arrival of the sun to the earth's surface. After analyzing 20 samples of ice, scientists have been able to determine the levels of sulfate in the atmosphere that prevailed last year by year. To do this, they used a new algorithm refines the analysis accuracy considerably.

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The key to success, say the authors, lies in the multidisciplinary approach of the study, which involved geologists, climatologists, astronomers and historians. The latter have traced written testimony on atmospheric observations such as decreased sunlight, fading of the solar disk, the appearance of solar crowns and frequency of over-red sunsets.

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One of the most valuable contributions of the new study was to elucidate what triggered one of the most serious climate crisis in history, which occurred in the sixth century AD. In March 536, a mysterious cloud covered the sky of the Mediterranean area, a phenomenon that lasted 18 months.

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The cause was, we now know, a major eruption in the Northern Hemisphere. Furthermore, the cooling of the climate was accentuated when, four years later, another volcano awoke somewhere in the tropics. For 15 years, summers were exceptionally cold circumstances that ruined crops and caused terrible famines. Surely, he helped to aggravate the plague that decimated the population of the Eastern Roman Empire between 541 and 543.