Tech & Science

An Atmospheric Scientist Explains Why That ‘Mini Ice Age’ News Is Bogus

sunspot
A large number of sunspots are indicators of a highly active 11-year solar cycle. Models suggest a much less active cycle is coming in the 2030s—but that doesn't mean much for those of us on Earth. Handout/NASA/SDO/Reuters

Last week, a press release from the Royal Astronomical Society caught the British news media’s attention. It quickly spread to American outlets, and soon headlines blared across the Internet announcing the coming of a “mini ice age” in 15 years. “Winter is coming,” announced one. “Scientists warn the sun will 'go to sleep' in 2030,” ominously intoned another. Global warming skeptics announcing their vindication on Twitter followed shortly thereafter.

The problem is, none of this is true.

The press release in question was an announcement of a presentation to be given by Valentina Zharkova, a professor of mathematics at Northumbria University in Newcastle, at the National Astronomy Meeting in Llandudno, Wales. She and her team of researchers had analyzed the sun’s 11-year cycles from a purely astronomical perspective and found that the solar cycle that will come into force in the 2030s looks much like the one last seen in the mid-17th century, a time period known as the Maunder Minimum, when Europe and North America experienced particularly bitter winters. “Solar activity will fall by 60 percent during the 2030s to conditions last seen during the 'mini ice age' that began in 1645,” the press release said.

The trouble is, the press release said nothing about what implications that solar cycle would have for conditions on Earth. It described conditions only on the sun. Yet the headlines announced a deep freeze anyway. Outlet after outlet echoed a line from the press release that solar activity would “fall by 60 percent.” Any reader who took a moment to digest the severity of that statement ought to have gone into a panic.  

“A decrease in solar output of 1 percent would be a very big deal for the climate system. A 60 percent decrease would end all life on Earth, forever probably,” says James Renwick, a professor at Victoria University of Wellington in New Zealand and an expert in atmospheric physics, via email. “I am kind of surprised no one much has commented on this yet or pointed out how unlikely it is.”

What Zharkova and her co-authors meant, Renwick explains, was that the amplitude of the solar cycle may decrease by 60 percent during that period. In other words, during an 11-year period in the 2030s, the two magnetic waves that produce sunspots—temporary phenomena that correlate with higher levels of solar activity—are predicted to interact in such a way as to nearly cancel each other out, causing a 60 percent drop in the difference between peak and height solar activity, as compared with the 11-year-cycle before. This would equal a decrease in solar output of roughly 0.1 percent, according to Renwick.

What would a 0.1 percent drop in solar output mean for us? Not a whole lot.

“If things played out as described in Zharkova's paper, and we did see a decrease in solar output roughly as happened in the 1700s, there would be some cooling for 20 or 30 years,” according to Renwick. “But the levels of CO2 and other greenhouse gases are so much higher now (and will be even higher in 2030) that temperatures would not drop much below where they are today. And that drop would last only until 2050 or so. Then we'd have a bounce upwards again.”

Howard Diamond, the program director for the federal U.S. Climate Reference Network, came to the same conclusions. “Regionally, there may be more cooling, but overall the globe would go back for a while to conditions experienced in the first half of the 20th century,” he says, hardly a period of unusual cold. “Once the solar cycle strengthened again, we would be back to greenhouse gas-related warming again.

In other words, this won’t solve our little climate change problem. Sorry, Internet.

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