A mini ice age could hit the Earth in the 2030s, the first such event to occur since the early 1700s. New mathematical models of the Sun's solar cycle developed at Northumbria University suggest solar activity will see a "significant" drop, causing temperatures on Earth to plummet.
The last mini ice age occurred between 1645 and 1715 and caused temperatures in northern Europe to fall dramatically, with London's River Thames freezing over during winter and sea ice extending for miles around the UK. The prolonged cold snap, known as the Maunder Minimum, has been linked to a reduction in the number of sunspots, as observed by scientists at the time.
Such periods were thought to be driven by convecting waves of fluids deep within the Sun, but new research suggests a second force -- or "wave" -- is at play. Two waves, operating at different layers in the Sun's interior, are now believed to drive solar activity. When these waves are desynchronised, temperatures on Earth fall.
Both waves work on 11 year cycles and fluctuate between the northern and southern hemispheres of the Sun. When the waves stay in phase we see high levels of solar activity such as sunspots, and when out of phase we see low activity.
Such events are in no way linked to climate change, with fluctuations in solar activity having a far smaller impact than global warming.
Valentina Zharkova, a mathematics professor at Northumbria University, who led the research, said comparing predictions to real data about current solar activity showed an accuracy of 97 percent. The findings were presented at the National Astronomy Meeting in Llandudno, Wales.
To test their theory Zharkova and her colleagues used solar activity data from 1976-2008. Once it was clear the theory matched they used their model to predict how the two separate waves would behave during the next solar cycles.
They found that by cycle 25, which peaks in 2022, the pair of waves would be increasingly offset. During cycle 26, covering the period 2030-2040, the two waves will be exactly out of synch, causing a "significant reduction" in solar activity. "In cycle 26, the two waves exactly mirror each other – peaking at the same time but in opposite hemispheres of the Sun. Their interaction will be disruptive, or they will nearly cancel each other. We predict that this will lead to the properties of a 'Maunder minimum'," Zharkova said.
If correct -- further study is naturally required -- Zharkova's prediction would mean a return to freezing temperatures last seen 370 years ago. During that period the River Thames froze to such an extent that regular "frost fairs" were held during the winter, with market stalls and ice skating a common sight on the river.
During the winter of 1683-84 the river was frozen solid for two months at a thickness of 28cm, according to historical records. Solid ice was also reported extending for miles off the coasts around England, France, Belgium and the Netherlands.
This article was amended to make it clear that fluctuations in solar activity are in no way linked to global warming. A clarification has also been made as to how significant the drop in solar activity is likely to be.
This article was originally published by WIRED UK
