FEB 13, 2018

Will climate change stop when the sun cools down by mid-century?

WRITTEN BY: Kathryn DeMuth Sullivan

By the middle of this century, the Sun may cease to exist as we know it. Just kidding, it won’t cease to exist, but it will experience a solar event that scientists call a grand minimum, which is when the Sun's magnetism diminishes. As a result of this, sunspots will form less frequently and less ultraviolet radiation will reach Earth’s surface, causing a cool period on our dear planet. This is a fairly common event in the history of the planet, so it’s nothing to be alarmed about, but it does beg the question: How will such cooling affect climate change?

New research recently published in Astrophysical Journal Letters explains how a team of scientists from UC San Diego determined the “significant probability of a near-future grand minimum,” according to Science Daily. In order to come to this conclusion, the team analyzed 20 years of data from the International Ultraviolet Explorer satellite mission. Using stars similar to the Sun as baselines in order to identify patterns of minima events, the team discovered a downward sunspot pattern in recent solar cycles of the Sun. Given that this pattern has been characterized as foreplay for previous grand minimum events, the team was able to determine the probability that the next similar solar event will occur by mid-century.

"Now we have a benchmark from which we can perform better climate model simulations," said lead researcher and physicist Dan Lubin at Scripps Institution of Oceanography at the University of California San Diego. "We can, therefore, have a better idea of how changes in solar UV radiation affect climate change."

But let’s back up. Grand minimum? That sounds like just a couple of random words thrown together. What are they even talking about?! In order to understand this phenomenon, we have to know something about the Sun’s magnetic field and its natural fluctuations. Watch the video below to get a quick lesson.

So now you know that radiation levels from the Sun peak and decline naturally because of the Sun’s fluctuating magnetic field. That’s what’s happening during a grand minimum, just to an extreme. This, in turn, affects us here on Earth, with one of the first felt consequences being a thinning of the stratospheric ozone layer which causes temperature changes in the stratosphere and in turn affects weather patterns.

We’ve already seen this happening in Earth’s history. One of the times this occurred was called the “Maunder Minimum,” when, in the mid-17th Century, a particularly cold period hit Europe. But it’s important to note that while areas of Europe got frostier during this time, other regions like Alaska and southern Greenland felt warming.

So, back to the question of climate change. Lubin says that this minimum will not be enough to curb the effects of climate change, although it might slow it for a time. According to several models estimating what a Maunder Minimum-like grand solar minimum would mean for our planet in its current state, after an initial decrease in solar radiation, by the time the solar event ended, the warming will catch up to its original state. In other words, no, a grand solar minimum will likely not save us from climate change. Darn. 

Sources:Science Daily, Astrophysical Journal Letters