July 2015 – GEOLOGY – A scientist who claims waning solar activity in the next 15 years will trigger what some are calling a mini ice age has revived talk about the effects of man-made versus natural disruptors to Earth’s climate. Valentina Zharkova, a professor of mathematics at Northumbria University in the United Kingdom, used a new model of the sun’s solar cycle, which is the periodic change in solar radiation, sunspots and other solar activity over a span of 11 years, to predict that “solar activity will fall by 60 percent during the 2030s to conditions last seen during the ‘mini ice age’ that began in 1645,” according to a statement.
At the National Astronomy meeting in Llanduno, north Wales last week, Zharkova said that a series of solar phenomena will lead to a “Maunder Minimum,” which refers to the seven decades, from 1645 to 1715, when the sun’s surface ceased its heat-releasing magnetic storms and coincided with the Little Ice Age, a period of chillier temperatures, from around 1550 to 1850 in Europe, North America and Asia, according to NASA. “The upcoming Maunder Minimum is expected to be shorter than the last one in 17th century (five solar cycles of 11 years),” Zharkova told Live Science in an email. “It will be lasting about three solar cycles.”
However, many scientists are not convinced. Georg Feulner, the deputy chair of the Earth system analysis research domain at the Potsdam Institute on Climate Change Research, has studied the effect a solar minimum might have on Earth’s climate. His research has shown that temperature drops correlated to a less intense sun would be insignificant compared with anthropogenic global warming, according to the Washington Post. Regarding the Maunder Minimum predicted by Zharkova, Feulner said, “The expected decrease in global temperature would be 0.1 degrees Celsius at most, compared to about 1.3 degrees Celsius since pre-industrial times by the year 2030,” Feulner told the Post. Furthermore, this isn’t the first time research has predicted waning heat from the sun, to which experts also said that man-made global warming won’t be trumped.
Solar cycles rise and fall over an 11-year cycle, though each cycle is unique. The sun can emit extreme ultraviolet and X-ray emissions that heat the part of the sky where planes fly. “Although the change in total solar irradiance seems too small to produce significant climatic effects, there is good evidence that, to some extent, the Earth’s climate heats and cools as solar activity rises and falls,” wrote David Hathaway, a solar physicist with NASA’s Ames Research Center, in a 2010 review paper published in the journal Living Reviews in Solar Physics. The Maunder Minimum was named by solar astronomer John Eddy in 1976 after E.W. Maunder, an English scientist who, along with German scientist Gustav Spörer, first noticed the decrease in solar activity in the 1890s, according to the New York Times. “I have re-examined the contemporary reports and new evidence which has come to light since Maunder’s time and conclude that this 70-year period was indeed a time when solar activity all but stopped,” Eddy wrote in the Times. –Live Science
Extreme changes in climate, as depicted in science fiction more than 50 years ago