The Sun's activity is at its lowest for 100 years, scientists have warned. They say the conditions are eerily similar to those before the Maunder Minimum, a time in 1645 when a mini ice age hit, Freezing London's River Thames. Researcher believe the solar lull could cause major changes, and say there is a 20% chance it could lead to 'major changes' in temperatures.
Conventional wisdom holds that solar activity swings back and forth like a simple pendulum. At one end of the cycle, there is a quiet time with few sunspots and flares. At the other end, solar max brings high sunspot numbers and frequent solar storms.
It's a regular rhythm that repeats every 11 years. Reality is more complicated. Astronomers have been counting sunspots for centuries, and they have seen that the solar cycle is not perfectly regular. 'Whatever measure you use, solar peaks are coming down,' Richard Harrison of the Rutherford Appleton Laboratory in Oxfordshire told the BBC.
'I've been a solar physicist for 30 years, and I've never seen anything like this.' He says the phenomenon could lead to colder winters similar to those during the Maunder Minimum. 'There were cold winters, almost a mini ice age. 'You had a period when the River Thames froze.'

The Frozen Thames, 1677 - an oil painting by Abraham Hondius shows the old London Bridge during the Maunder Minimum
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