The sun has been the main driver of global climate change over the last billions of years. The sun provides us with the energy that we need to have a normal life on Earth. Changes in the composition and intensity of the Earth’s radiation can cause changes in global and regional solar radiation. Solar variability also refers to changes in sunspots. The number of sunspots is counted in an 11-year cycle. The solar impact is quite significant in forming the local climate. For example, the European winters have changed a lot. More than ten years ago, Central Europe had really cold winters. Scientists found out that during that time, the number of sunspots was also lower than normally.
On the other hand, if we compare solar activity with greenhouse gases, then the impact of greenhouse gases is a lot bigger globally. Proof that solar activity causes climate change comes from analyses over a number of time scales and from a variety of sources, including direct observations, composites of different proxy observations, and numerical climate models. The variation in solar irradiance has two main sources. Firstly, there are interstellar processes that influence the total solar irradiance and the activity of the sun. Secondly, variations in the Earth’s orbit around the Sun over a period of tens and hundreds of thousands of years have a direct effect on the amount of radiant energy that reaches the Earth and its global distribution.

The solar cycle is probably the best-documented record of solar activity in our terrestrial environment. Numerous atmospheric data points show that the solar cycle has an impact on the Earth’s climate. In the last few hundred years, scientists have been noticing changes in solar activity. The number of sunspots has increased, and during this time, the Earth’s temperature has also increased. We also have hundreds of years of information about the aurora. Aurora is also called the Northern or Southern Lights. Aurora appears when the energetic particles in the solar wind interact with the atmosphere and is more frequently observed when the sun is more active. Aurora itself doesn’t affect climate change. Scientists think that the changes in the atmosphere will affect the observation of aurora borealis on Earth because of the gaseous condensation changes in the Earth’s atmosphere and magnetosphere.

Sunspots are the dark spots on the solar disk. We have data for the sunspots from the 17th century, when the telescope was invented. The number of sunspots has been growing and decaying regularly. Although there have been some irregularities. For example, in the 17th century, when the number of sunspots was near zero for decades. At the start of the 19th century, there were a lower number of sunspots as well. This summer, in June 2023, the number of sunspots was 163, which was the highest value over the last 20 years. When the number of sunspots is higher, then on Earth we will see more aurora borealis. There can also be distribution in radio transmissions and power grids. Scientists have noticed some connections between the number of sunspots and the climate. For example, the “Little Ice Age” occurred during the minimum number of sunspots.

In conclusion, changes in solar activity can cause climate change, but nowadays the main cause of climate change is greenhouse gases. We also can’t say how much solar activity causes the changes in climate because we don’t have enough data to draw conclusions. Satellites have been tracking the sun’s energy output for more than 40 years, during which it has risen or fallen by less than 0.1%. From 1750 on, the greenhouse gas warming caused by burning fossil fuels was more than 270 times higher than the small additional warming caused by the sun itself over the same period. Right now, scientists are actually expecting a decrease in the number of sunspots, which might lower the Earth’s temperature by around 0.3 degrees. Unfortunately, that will only slow down a little the human-caused global warming.

Sources:
https://en.wikipedia.org/wiki/Solar_activity_and_climate
https://www.imperial.ac.uk/media/imperial-college/grantham-institute/public/publications/briefing-papers/Solar-Influences-on-Climate—Grantham-BP-5.pdf
https://www.omicsonline.org/open-access/solar-cycle-variability-and-global-climate-change-2157-7617-1000514-109027.html
https://climate.nasa.gov/explore/ask-nasa-climate/2910/what-is-the-suns-role-in-climate-change/#:~:text=Warming%20from%20increased%20levels%20of,0.1%20percent%20during%20that%20period.
https://perlan.is/articles/climate-change-northern-lights
https://www.space.com/sun-highest-sunspot-number-since-2002
https://www.weather.gov/fsd/sunspots
https://metanexus.net/link-found-between-cold-european-winters-and-solar-activity/