‘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.’