Scientists believe that the sun will be experiencing a “grand minimum” in the coming decades, which could have a dramatic cooling effect on our Earth at a time when concerns about global warming continue to grow. It is unlikely to offset the temperature rise caused by humans, and in any event it would only be temporary, but the sun could cool dramatically around 2050, scientists believe.

The sun warms and cools due to its fluctuating core on an 11-year cycle, and while that cycle is fairly consistent, occasionally we get what is called a “grand minimum” when the sun cools an exceptional amount. During such a period, the sun ejects less radiation and generates fewer sunspots and flares.

The last major grand minimum was in the 17th century, known as the “Maunder Minimum.” The event had a big impact on humans, as it froze the Thames river in England and the Baltic Sea. Physicist Dan Lubin of the University of California San Diego authored the paper and is trying to pinpoint the exact timeframe and how much cooler it might get, though he estimates it would be about 7 percent cooler than a standard minimum.

“The Sun might emit less radiation by mid-century, giving planet Earth a chance to warm a bit more slowly but not halt the trend of human-induced climate change,” reads the statement from the university. “The cooldown would be the result of what scientists call a grand minimum, a periodic event during which the Sun’s magnetism diminishes, sunspots form infrequently, and less ultraviolet radiation makes it to the surface of the planet. Scientists believe that the event is triggered at irregular intervals by random fluctuations related to the Sun’s magnetic field.”