Amid rising concerns over the effects of global warming, a group of scientists has claimed that the Earth could in a little over a decade be hit by a "mini ice age" that would freeze major rivers.

The startling prediction is based on a mathematical model of the Sun's magnetic energy which also suggests that Earth's temperature will start dropping in 2021. The plummeting temperature will then lead to something called the "Maunder minimum", which is referred to a previous mini ice age that occurred between 1646 and 1715, turning London's Thames into a frozen river, scientists claimed.

The latest research, led by maths professor Valentina Zharkova at Northumbria University, is built on a previous research that predicts the movements of two magnetic waves produced by the Sun. It also foretells rapidly decreasing magnetic waves for three solar cycles that will begin in 2021, and last for as many as 33 years.

According to the model, the two magnetic waves will become increasingly offset during Cycle 25, which peaks in 2022. During Cycle 26 between 2030 and 2040, the waves will become out of sync, causing reduction in solar activity by as much as 60 percent.

"In cycle 26, the two waves exactly mirror each other — peaking at the same time but in opposite hemispheres of the Sun," Zharkova reportedly said in 2015 while conducting a previous research on the phenomenon. "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'."

Although Zharkova claimed 97 percent accuracy for the model that corresponds to previous mini ice ages, she did warn that her model could not be used as proof of a future mini ice age, partly because of global warming. The new research paper on the findings was published this year in Astronomy & Geophysics.

"I hope global warning will be overridden by this effect, giving humankind and the Earth 30 years to sort out our pollution," Zharkova told Sky News, adding that any possible downward impact on global warming will last until 2050s when the Sun's two magnetic waves become active again.

"We have to be sorted by that time and prepare everything on Earth for the next big solar activity," Zharkova said.