The Sun three years ago, when storms were still visible on its surface. This image was taken by Matt Francis, director of the Prescott Observatory.
No question: The Sun has been behaving very oddly. First we had a drawn-out cycle, number 23, whose sunspot “minimum” was deeper and more free of spots than any that we’ve observed this past century. When the new cycle number 24 finally began in 2008, nearly two years behind schedule, solar experts wondered if the odd behavior would continue.
It has indeed. And we had a stake in the outcome. In an op/ed that accompanied the publication of my book The Sun’s Heartbeat, I wrote in 2011 that “global temperatures are now so steadily high that, even with the recent reduced rate of warming, 2010 still managed to join 1998 as the warmest years ever recorded.
“If the upcoming solar max of cycle 24 is normal or robust, and especially if an El Niño follows it two years later (as often happens), then the middle of this decade will be the hottest period since humans arrived on Earth. However, if the upcoming maximum is wimpy, as most solar researchers expect, or if the Sun is now entering an extended period of low activity with another deep minimum to follow, that is the best thing it could possibly do for us. Such a scenario would mitigate climate change. Essentially, the Sun has been buying us time.”
Want to know what happened? Well, cycle 24 has now run almost its course. Its “maximum,” in 2014, was the lowest sunspot peak since the early 1800s. That was followed by years of sunspot decrease, until now, this past year, we’ve gone weeks at a time without a single spot on the Sun’s face. We are bottoming out now, with almost no solar-storm activity.
This affects us because Earth’s climate gets cooler when there are fewer solar storms. The extreme example happened between 1645 and 1715, when the normal 11-year sunspot cycle disappeared! The Sun’s heartbeat vanished. This period, called the Maunder Minimum, was accompanied by bitterly cold winters in the American colonies. Fishing settlements in Iceland and Greenland were abandoned. Icebergs were seen near the English Channel. The canals of Venice froze. It was a time of great hardship.
Since no one understands why the 11-year sunspot cycle could simply stop for a full human lifetime (in that case, it coincided with the rule of the French “Sun King,” Louis XIV), we can’t know if we’re really currently on the cusp of a repeat performance. But if this strange recent solar activity means that another Maunder Minimum is nearly upon us, as a few solar researchers believe, it would be mitigating Earth’s warming at the best possible time. We’ll have to wait and see.
For the moment, if you have a leftover solar filter from last August’s eclipse, take a glance at the Sun these days. You’ll see a strange blank disk.