The lack of sunspots this year has some scientists wondering if this could be an indicator that much colder weather is on the way.

They argue it could be the start of an extended period of solar indolence that would more than counter the effect of human-produced carbon dioxide emissions.

From the middle of the 17th century to the early 18th century, which is known as the Little Ice Age, sunspots were very rare and this reduced activity is believed by some to be related to the lower temperatures which occurred then.

On more than 200 days so far this year, no sunspots have been spotted. This makes the sun more unblemished than it has been in any year since 1954 when it was spotless for 241 days.