Was Jon Snow right after all to constantly warn us that winter is coming? The story of a potential ice age is on fire everywhere, from science blogs to the Weather Channel to terrified twitter updates to apocalyptic websites predicting end of all days. “Scientists warn the sun will ‘go to sleep’ in 2030 and could cause temperatures to plummet,” scared a couple of headlines this weekend.“Earth heading for ‘mini ice age’ within 15 years,” warned another. I’m already imagining a frozen New York, like they showed in the dramatic end-of-the-world movie ‘Day After Tomorrow’.
The rumor began after a recent presentation at the Royal Astronomical Society’s national meeting. Researchers studying sunspots discovered that solar activity is declining at an alarming rate and that in the next few decades it could possibly reach a stage known as the ‘Maunder minimum’. This has happened in the 17th century, when the downfall happened to coincide with what’s called the “Little Ice Age,” when Europe’s winters turned brutally cold, crops failed and rivers froze over.
Though University of Northumbria mathematics professor Valentina Zharkova, who led the sunspot research, did find that the magnetic waves that produce sunspots (which are associated with high levels of solar activity) are expected to counteract one another in an unusual way in the coming years, the press release about her research mentions nothing about how that will affect the Earth’s climate. Zharkova never even used the phrase “mini ice age.”
Meanwhile, several other recent studies of a possible solar minimum have concluded that whatever climate effects the phenomenon may have will be dwarfed by the warming caused by greenhouse gas emissions.
Besides, that “Little Ice Age” that occurred during the Maunder minimum, it was not global but just confined to Europe – and it may as well have been caused by plumes of ash from volcanic eruptions instead of fluctuations in solar activity. The eruption of Indonesia ‘Krakotoa‘ is one explanation.
However, hardly anyone stops to think before spreading mass mania on the internet about an upcoming ice age. Way too exciting to just play along and make fun of posts which warn you about ‘global warming’.
John Casey, president of the Orlando-based Space and Science Research Corporation, which denies that global temperatures are rising, has written two books on the threat of impending “solar hibernation.” In 2011, when a series of studies concluded that the sun was heading into a cycle of unusually low activity, one headline cheered “Global Warming Be Damned, We Might Be Headed for a Mini Ice Age.”
For decades, scientists have known that solar activity fluctuates according to a roughly 11-year cycle. Sunspots which are (relatively) cooler, dark blotches on the sun’s surface — indicate areas of intense magnetic activity. But recently sunspots have been decreasing in intensity, as has the sun’s magnetic field, causing many scientists to conclude that the sun is heading into an especially quiet cycle termed the “grand solar minimum”
The new research from Zharkova debates that the solar cycles are regulated by not one but two magnetic waves fluctuating at slightly different frequencies, and that the unusually low activity can be explained by the waves getting far enough out of sync that they effectively cancel one another out.
Even if the upcoming decline in solar activity turns out to be as Zharkova’s suggests, scientists who study the sun say we can’t be sure how it will affect Earth’s climate.
“We have some interesting hints that solar activity is associated with climate, but we don’t understand the association,” Dean Pesnell, a NASA scientist who worked on one of the 2011 studies about the grand minimum, told National Geographic at the time.
Those studies that have found a correlation between solar activity and global temperatures predict that the drop in temperatures associated with a grand minimum will be much smaller than the warming that’s predicted to occur due to greenhouse gas emissions: A 2010 study in the journal Geophysical Letters predicted it could cause a global temperature decrease of about 0.3 degrees Celsius by 2100 — not nearly enough to offset the 1 to 5 degree increase anticipated from human-caused global warming.
“I’d be surprised if it froze again to the extent where we’d be able to allow large numbers of people on the Thames,” he said.