Blame it on the witches. That’s what people in the 1500s did when sudden hailstorms ruined crops and killed livestock.
Photo credit Photos: ESA/NASA Solar and Heliospheric Observatory . The photo above was taken Sept. 27, 2008 and shows the sun unmarked by spots. Below the sun on Sept. 27, 2001, with the sun’s face peppered with sunspots. The difference is the phase of the 11-year solar cycle. The year 2001 was a year of solar maximum, with lots of sunspots, while 2008 was at the cycle’s opposite extreme, solar minimum, a quiet time on the sun.
But the explanation isn’t that simple, according to Sallie Baliunas, astrophysicist at the Harvard-Smithsonian Center for Astrophysics and this year’s Nerenberg Lecture speaker.
“(It was) a capital crime to cook weather that would make this happen,” she said. But freak storms and weird weather are part of a larger pattern of climate that stems from sunspots, she added.
Baliunas explained to a packed crowd in Conron Hall March 26 the controversial theory of sunspots, which have long been studied but not popularized in the media.
The idea, she said, is that the sun generates magnetic fields that produce regions on its surface that are cooler than their surroundings, which make them look like dark spots. The numbers of sunspots dramatically rise and fall in cycles of about 11 years, and the Earth’s climate is affected in different ways in that time, depending on how many sunspots there are.
While the popular reason for climate change is based on the affect of humans on the Earth, Baliunas argues it’s simply the state of the sun.
Just in the way the sun’s magnetic field interferes with the Earth’s to create an aurora borealis, it has an affect on climate, she said.
Galileo was the first to study sunspots in the 1600s. Historical records show only 50 sunspots were counted between 1672 to 1699, while 40-50,000 were counted in a similar time frame in the 1900s, Baliunas noted.
Now, the Earth’s headed for a Maunder Minimum, meaning very few sunspots, because their numbers haven’t risen as expected since 2007, she said, adding this means we’re headed for unexpected weather by around 2020.
“We are overdue,” but there’s no good way to predict climate change because there isn’t a good scale in place to make a precise judgment, she said.
Sunspots have been studied at Western – physics and astronomy professor David Gray co-wrote a few papers about them with Baliunas 10 years ago.
He said patterns of the Earth can be found in tree rings and seabed deposits, which grow in a cadence of about 11 years, like sunspots.
“If that energy to the Earth varies in any way, our climate changes. The question comes down to how much we’re affecting it and how much the sun is affecting it,” he said.
The issue’s politically important for Canada in terms of whether to fund hybrid vehicles or seize carbon monoxide from oil sands, he added.
“The more information we have, the more we deeply understand things. If we go in the wrong direction, we’re going to be in trouble.”
The Nerenberg Lecture series, which began in 1998, is known for choosing fringe topics and speakers that help inspire discussions about science and attract a wide range of attendees, not just academics.
Baliunas has won a number of science and film awards, was named one of Discover Magazine’s outstanding women scientists in America, and was a science advisor for Gene Roddenberry’s Earth: Final Conflict.
Named after the late Morton (Paddy) Nerenberg, a former applied mathematics professor at Western, the lecture series is meant to honour his appreciation for the democracy of ideas.
Two of his children, Albert and Simone Nerenberg, attended this year’s lecture and said it’s great to see their father’s work being honoured every year with interesting speakers.
“I thought (the lecture) was intriguing,” said Albert. “It raises all these questions about climate change. I think everyone knows that it’s more complicated than you think.”
The writer is a Western journalism program graduate and London freelance writer.