This photo from the Solar and Heliospheric Observatory shows what the sun looks like without sunspots.
As I write this, the outside temperature here in Portland, Oregon, is 98 degrees, as it’s been nearly every day this week. Yep, this is Global Warming for sure. And then I see an article – complete with a linked press release from NASA – about the potential for serious Global Cooling.
It seems we’re now well beyond Day 400 of no sunspot activity.
You may ask: “So what?”
It so happens that a lack of solar activity prompts a serious drop in Earth’s temperature and leads to severe cooling – known in the extreme as an Ice Age.
You may say: “But I thought we were experiencing Global Warming.”
Yes, well, that’s part of the confusion. This past winter saw record snowfalls in the Northeast, Britain had its coldest spring in decades, and China experienced its coldest winter in 100 years. Just yesterday the Chicago Tribune reported that there have been only 162 days of 90-degree-plus days since the year 2000, the fewest hot days in the city since 1930.
To quell growing concern in both the scientific and lay communities, NASA has released a press release. In it, NASA solar physicist David Hathaway says: “The sun is now near the low point of its 11-year activity cycle. We call this ‘Solar Minimum.’ It is the period of quiet that separates one Solar Max from another.” The press release states:
During Solar Max, huge sunspots and intense solar flares are a daily occurrence. Auroras appear in Florida. Radiation storms knock out satellites. Radio blackouts frustrate hams. The last such episode took place in the years around 2000-2001.
During Solar Minimum, the opposite occurs. Solar flares are almost nonexistent while whole weeks go by without a single, tiny sunspot to break the monotony of the blank sun. This is what we are experiencing now.
“It does seem like it's taking a long time,” Hathaway went on. “But I think we're just forgetting how long a solar minimum can last.”
The longest minimum on record is the Maunder Minimum of 1645-1715. During the 70-year period – called the Little Ice Age – a series of extraordinarily bitter winters hit Earth's northern hemisphere. Many researchers are convinced that low solar activity, acting in concert with increased volcanism and possible changes in ocean current patterns, provoked that 17th century cooling. During that cold spell, only about 50 sunspots appeared as opposed to the typical 40,000–50,000 spots.