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Understanding the solar cycle and its impact on our climate and climate change

As part of The Climate Change Project, we’ve been asking you for your story ideas and questions. One that has repeatedly come up is around the solar cycle and in particular, how the sun ties into climate and climate change.

As we close in on a peak in solar activity, what are the implications for life on Earth?

The vast differences in activity on the surface of the sun, as shown through the solar maximum in April 2014 , left, and solar minimum in December 2019, right. (NASA/SDO)

The Prairies Climate Change Project is a joint initiative between CBC Edmonton and CBC Saskatchewan that focuses on weather and our changing climate. Meteorologist Christy Climenhaga brings her expert voice to the conversation to help explain weather phenomena and climate change and how they impact everyday life.

As part of The Prairies Climate Change Project, we've been asking for your story ideas and questions. One that has repeatedly come up is around the solar cycle and in particular, how the sun ties into climate and climate change. 

As you can imagine, the answer is … complex.

We all know that the sun and weather go hand in hand. Without the sun there would be no life on Earth. But the sun is not completely consistent. It goes through cycles, sometimes with lots of activity, and other times with much less. 

Right now we are in Solar Cycle 25 — the 25th cycle since we began recording sunspot activity closely in 1755.

We are just climbing out of the sun's minimum activity toward its stormy season, set to peak in 2025. According to a senior scientist with the Canadian Space Agency, forecasts show this solar maximum could be more active than expected and than others seen so far this century.

So as we close in on the peak in solar activity, what are the implications? And what is the connection between the sun's cycles and climate change?

Storm season on the sun

The sun acts like a big magnet. It has its own magnetic field. That magnetic field is what drives the solar cycle. 

"The sun goes through active periods, quiet periods … just in the way the Earth does," says John Manuel, senior program scientist of solar terrestrial sciences at the Canadian Space Agency.

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"As the solar wind that continually comes out of the sun blows past the Earth, it carries very energetic, very hot particles and magnetic fields which interact with the Earth."

The cycle of the sun is measured on roughly 11-year intervals. It begins and ends with quiet solar activity, with a maximum stormy season around the midway point.

At that time, the sun's magnetic field will completely flip — magnetic north becomes south or vice versa. The magnetic field will remain flipped until the next solar cycle's maximum.

During that stormy season, the surface of the sun is peppered with sunspots, cooler regions that can produce what we call space weather.

This image of the sun from Oct. 3 shows several sunspots. These regions can release powerful bursts of energy and are often followed by an ejection of material called a coronal mass ejection. (NASA/Solar Dynamics Observatory)

"A sunspot's magnetic field gets all twisted up like rubber bands … and released. When that happens it's what we call a coronal mass ejection," say Robert Leamon, a scientist at the University of Maryland and NASA Goddard Space Flight Center.

Those coronal mass ejections can happen in any direction, including toward our planet.

"Our Earth's magnetic field protects us from the particles streaming from the sun most of the time, but for a big enough storm … then our our shields break down," Leamon says.

How space weather affects Earth

Space weather can affect us in a number of ways. Here in Canada, many areas are treated to displays of the aurora, a product of solar activity.

But strong solar storms can also cause electrical failures and problems with GPS and communication, all of which are becoming more and more important in our technology-driven world.

"We all rely increasingly on technology, and you know we're at the mercy of this big yellow ball in the sky and its occasional tantrums," says Leamon. 

An electrical failure in Quebec in 1989 brought the implications of space weather to light, when enhanced solar activity caused a provincewide power failure.

"The activity in the very upper atmosphere generated electrical currents in Hydro-Quebec's power system, which caused the circuits to be overwhelmed and the power just quit," says Manuel.

"It wasn't returned until later the same day, and that was a cold day in February. So it really had an impact."

More recently, in February of this year, we saw the effects of space weather in the form of a failed satellite launch.

A SpaceX Falcon 9 rocket launches 49 Starlink satellites on Feb. 3. A solar storm knocked most of the satellites out of orbit, leaving them to burn up in Earth's atmosphere. (SpaceX)

"Because the atmosphere of the Earth had gotten a little hot at the very top where it meets space, that heat caused the atmosphere to expand," Manuel says.

The changes to the atmosphere caused more drag, preventing 40 of the 49 launched satellites from making it to orbit. 

What about climate?

Here we are at the million-dollar question, one that is tricky to answer.

Manuel says that when it comes to climate and space weather, there are some things we know, but many we don't.

With climate change, the scientific community agree that greenhouse gases are the cause of climate change.

"Space weather affects Earth's climate. There is a connection. It's not a climate change-type connection, but there's an interaction between the weather and space," he says.

According to NASA, the solar cycle and its associated short-term changes in irradiance, or amount of light energy, cannot be the main force driving the changes in Earth's climate we are currently seeing.

NASA scientists say the energy from the sun only changes 0.15 per cent over the course of a cycle, which could not be responsible for the changes we have seen in recent decades.

"None of the research that I'm aware of indicates the connection that anything happening in space is causing climate change," says Manuel.

So although the solar cycle is not to blame for the changes we are seeing, it does have its place in the overall climate puzzle.

Finding that connection is a focus of a newly funded satellite mission called RADICALS out of the University of Alberta.

"To understand how the planet is going to respond we need to understand how these pieces fit together," says Ian Mann, a U of A physics professor who is working on the project. 

An illustration of the RADICALS satellite mission, set to launch in late 2026 or 2027. (Submitted by Ian Mann)

Mann says that during intense solar storms, radiation rains down. The energy is deposited high up in the atmosphere, about 50 kilometres above the Earth's surface.

That can change the characteristics of the atmosphere at that altitude. 

"It's possible that there's a connection between this space weather and this radiation as it's dumped into the atmosphere and the overall response … all the way down to tropospheric weather and climate," Mann says.

He is hoping to better understand that connection with RADICALS.

"We will for the first time make a very high-resolution measurement, a very accurate measurement of how much radiation is actually entering the atmosphere, and at what times."

With that information, Mann says information can be fed into climate computer models to better understand what's happening. 

"We have a made-in-Canada solution for going and basically measuring this potential pathway that may couple space weather and climate," he says. 

Mann says we will have to wait a little while for the data to roll in. The launch for the mission is slated for late 2026 or 2027, with hopes to capture as much of this cycle's stormy season as possible.

"A better understanding of how the highly interconnected systems of the Earth's environment...may help us to better understand and more accurately predict how much more severe the climate emergency may become as a result of the ongoing unprecedented levels of greenhouse gas emissions."

Our planet is changing. So is our journalism. This story is part of a CBC News initiative entitled "Our Changing Planet" to show and explain the effects of climate change. Keep up with the latest news on our Climate and Environment page.


Christy Climenhaga

CBC Meteorologist

Christy Climenhaga is a meteorologist and CBC Edmonton's climate reporter, covering the impacts of climate change for the Prairies. She has worked as a CBC on-air meteorologist for more than 10 years, in the North and Saskatchewan. Have a climate question? Reach out at christy.climenhaga@cbc.ca.