A new study has been published that illustrates a phenomenon known as the solar "grand minimum." Also, known as the "prolonged sunspot minimum," it’s a period when the Sun’s magnetic pull will diminish, sunspots will be less frequent, and less ultraviolet radiation will make it to Earth.
This is all due to random fluctuations in the Sun’s magnetic field. All of that can mean unusually cool temperatures for us, and it’ll also make the Sun appear dimmer.
The Sun is on an 11-year up/down cycle as it is, but this grand minimum will be especially cold, as the Sun’s activity will go lower than the regular 11-year low. That translates to colder temperatures for parts of the world.
How cold? Predictions, based on a study of previous sunspot reductions preceding a grand minimum period, are that we’ll see a 7% reduction in the Sun’s light and heat, and remember, that’s 7% lower than the lowest of the 11 year cycle that we usually see.
Such a grand minimum happened in the middle of the 17th century. Known as the "Maunder Minimum" (from the names of 2 well respected solar astronomers of the time, Anne Russel Maunder and Edward Walter Maunder), the resultant cold temperatures saw the river Thames freeze, and the Baltic Sea as well, which allowed a Swedish army to invade Denmark by marching across the ice.
At the same time, Alaska and Southern Greenland warmed, due to the thinning of the Earth’s stratospheric ozone layer, which changes wind and weather patterns around the world.
The exact date and severity of the event is still in question, but the clues all point to things bottoming out around the year 2050. It could start as soon as 2030, however. Just for reference, the Maunder Minimum lasted from 1645 until about 1715.
Will it save us from global warming? The very same scientists don’t think so.
“The cooling effect of a grand minimum is only a fraction of the warming effect caused by the increasing concentration of carbon dioxide in the atmosphere," according to the study.