Scientists have revealed that the sun will cool down by the mid-century. This will happen as the sun is predicted to emit less radiation during the period called the grand minimum.
Physicist Dan Lubin، from Scripps Institution of Oceanography at the University of California San Diego، and colleagues said that the ultraviolet radiation of the sun will be reduced by an additional 7 percent beyond the lowest point of the 11-year solar cycle during a grand minimum.
Because sunlight will be reduced during this period، global temperatures are expected to drop. The phenomenon appears to offer a natural solution to climate change، which experts fear could lead to a rise in sea level، flooding، and extinction of species. Unfortunately، Lubin and colleagues said that while the solar phenomenon will somehow slow global warming، it will not stop the current trend of human-induced climate change.
They explained that the cooling effect of the grand solar minimum is only a fraction of the warming effect linked to the increasing amount of planet-warming greenhouse gases in the atmosphere.
During the Maunder Minimum that occurred in the mid-17th century، the temperatures were low enough they froze the Thames River regularly. The cold period also froze the Baltic Sea to an extent that the Swedish army managed to invade Denmark in 1658 by marching across the sea ice.
In an earlier study that looked at how a Maunder Minimum-type grand minimum occurring in the future would impact the world's climate، researchers assumed that the total solar irradiance will drop by 0.25 percent over a period of 50 years starting 2020.
The findings revealed that after solar radiation drops in 2020، the surface average temperature worldwide will cool by up to several tenths of a degree Celsius. By the year 2070، however، researchers found that the warming would nearly catch up to the reference simulation، which means that a future grand solar minimum would merely slow down global warming.
"Now we have a benchmark from which we can perform better climate model simulations،" Lubin said.
A 2017 study found that there is a 90 percent increase in odds that global temperatures will increase from 2 degrees to 4.9 degrees Celsius by the year 2100. In worst-case scenarios، temperatures could rise 6 degrees Celsius higher than the temperatures in the pre-industrial times.
****The findings of the new study were published in the Astrophysical Journal Letters.