How does climate change impact the Northern Lights?

As the 21st century progresses, climate change increasingly dominates the news headlines. The impacts of rising global temperatures are felt all across the Arctic region and even though much of the country sits below the Arctic Circle, they haven’t escaped Iceland. Glaciers are retreating at a concerning rate and other effects such as changing weather patterns are also starting to be felt. But how does climate change relate to the Northern Lights? Let’s take a look and find out.

16.09.2024

Solar activity and climate change are linked; the sun is the source of energy that not only keeps the planet warm enough for us to be able to live, but also influences the earth’s climate, warming the atmosphere and creating wind patterns. A 2011 article by Professor Joanna Haigh of Imperial College London about solar influences on climate stated that:

“Over the past 150 years an overall increase in solar activity has probably contributed to global warming, mainly during the first half of the twentieth century. The effect is, however, estimated to be much smaller than the total net human forcing of the climate system through the emission of greenhouse gases and other factors.”

In recent decades, there has been a divergence between the earth’s temperatures and solar activity. Solar irradiance is on a downward trajectory while global temperatures show an upward trend. In other words, even though the sun has had a marginal cooling effect on our planet, the earth’s temperatures are still rising.

So though climate change is nothing new, most scientific evidence points the finger at the effects of people’s actions in worsening the situation. In 2019, NASA reported that:

“Since 1750, the warming driven by greenhouse gases coming from the human burning of fossil fuels is over 270 times greater than the slight extra warming coming from the Sun itself over that same time interval.”

But regardless of how much climate change has been impacted by the sun and how much by people’s actions, we can see that climate change is affecting our planet. The effect of greater greenhouse gas emissions are being felt globally in increased temperatures and unpredictable rainfall patterns.

So how does that relate to the aurora? Our understanding of solar activity, sunspots and the solar cycle is still evolving, but we do know that sunspots and solar radiation are connected. The more sunspots there are, the greater the amount of solar radiation is emitted. During the current solar cycle, there have been more sunspots than were initially expected; activity is set to peak soon.

We’ve seen that the Northern Lights are more common and more intense when sunspot activity reaches its zenith, which happens towards the solar maximum. It follows, therefore, that we can expect that the next couple of seasons should be active ones in terms of seeing the aurora borealis.

However, to go back to our original question, climate change doesn’t directly impact the Northern Lights, while solar activity does. That’s because our surface weather and climate originate in the troposphere or lower stratosphere. Solar storms don’t occur here, they happen much higher up, impacting the ionosphere and lower part of the mesosphere – in what we collectively describe as the earth’s upper atmosphere.

However, the Icelandic Met Office draws tentative conclusions that there might be an increase in precipitation intensity as a consequence of global warming. If one effect of climate change in Iceland might be to create more stormy and unpredictable weather, the resultant cloud cover might have a bearing on how easily we might see the aurora from the ground.

Fortunately, information from forecasting experts is easily available and maps showing the extent of cloud cover across Iceland are updated regularly. For those planning a Northern Lights hunt in the Reykjanes peninsula or beyond, this information is invaluable in helping determine where the clearest skies should be and improves your chances of success.