One consequence to climate changes due to human-induced global warming is the widening ozone layer hole above Antarctic. The sun can emit stronger UV rays without the protection of the ozone layer. However, a new study suggests that the Sun will be getting dimmer because it will be emitting less radiation, and is likely to occur in the middle of this century. Although, perhaps the sun getting dimmer would decrease the warming rate of our planet, it will likely not make global warming come an end.
This phenomenon which will bring down temperatures for a certain period of time is called a “grand minimum.” The Sun’s magnetism will be reduced, while sunspots on the star with form less often. As a result, less UV rays will enter Earth’s atmosphere. It is believed that random fluctuations in the star’s magnetic field are what causes this phenomenon, which occurs irregularly.
When grand minimums occur, it causes lower temperatures on Earth. The cooling in Europe which occurred in the middle of the 17th century is likely connected to grand minimum, the scientists suggest. The event caused lower temperatures, which caused the Thames to freeze over multiple times. At that time, the Swedish army attacked Denmark on foot, and marched over the Baltic Sea ice in 1658.
Researchers from the University of California San Diego used satellite data from Sun-like stars that are located nearby and predicted that a grand minimum in the near future is likely to happen. They were also projecting how much dimmer the Sun might get the next time this event occurs. According to them the sun will be dimmer by 7% below the minimum output at this time.
“Now we have a benchmark from which we can perform better climate model simulations,” physicist Dan Lubin said in a statement. “We can therefore have a better idea of how changes in solar UV radiation affect climate change.”
The sun getting dimmer will start several events on Earth. The first of those events will be the ozone layer on Earth thinning. The thinning of the ozone layer will impact the temperatures present in the stratosphere. However, even though cooling is likely to happen, it is not 100% certain. When the “Maunder Minimum” occurred in 17th century, Europe froze while certain areas of Alaska and Greenland recorded higher temperatures.
Lubin believes that the upcoming grand minimum can potentially slow the rate of global warming or even temporarily stop it. However, the cooling effect is smaller compared to the warming effect which is caused by fossil fueled emissions. That being said, even if the sun gets dimmer, usage of substances that induce global warming will still affect temperatures on Earth.
According to the statement, for hundreds of thousands of years the levels of CO2 have never exceeded 300 parts per million in air. However, the concentration of the greenhouse gas has now exceeded over 400 parts per million and it continues to rise, after it began during the Industrial Revolution. It is truly the greenhouse gas emissions that need to be lowered in order to keep our planet cool.