A reduction of heat from the sun, similar to levels last felt around 300 years ago, could help slow warming in the eastern section of the United States and Europe. It would however not be enough to do so on a global scale, according to a new study in the United Kingdom.
Scientists at the British Met Office Hadley Center and several other organizations reported that the sun has been highly active in the past several decades. They believe that its activity will nevertheless be lessened by as much as 20 percent over the next 40 years in a phenomenon known as grand solar minimum.
Sarah Ineson, a researcher at the Met Office and lead author of the study, explained that even with the occurrence of the Maunder minimum – a reduction of sunspot activity – its effect would not be enough to combat the warming of the world.
"The sun's not going to save us," Ineson said.
A Maunder minimum was last observed between the years 1645 and 1715. The period was marked by the freezing of the Thames.
The change in the world's climate means that such extraordinary events wouldn't occur in the next half century. The cooling effect of the sun would lessen manmade temperature increases in northern Europe and the eastern United States by only .72 to 1.44 degrees Fahrenheit.
While the projected offsetting cannot be considered as a "large signal," Ineson pointed out that their findings showed these regions would experience more frosty days than if there were no reduction in the sun's activity.
The Met Office researchers said they expect a stronger cooling effect during the period of weaker solar activity in the northern regions of Europe and eastern sections of the U.S., as compared with other areas.
This is because the reduction of ultraviolet rays in the stratosphere could potentially cause a chain reaction that could impact the climate in a phenomenon known as North Atlantic Oscillation (NAO), which influences winter on both sides of the Atlantic Ocean.
The potential impact on the NAO could also cause storms to form, mostly in southern regions. This would bring more rainfall to Europe's southern parts, which could offset the drying the region would experience due to climate change.
Experts, however, theorize that this scenario would only affect the world on a relatively small scale.
The grand solar minimum is expected to reduce global temperatures by only 18 degrees Fahrenheit from 2050 to 2099.
The effects of man-made climate change, on the other hand, would increase global temperatures by as much as 11.88 degrees Fahrenheit during the same years, unless efforts to reduce global carbon emissions are made.
Scientists warn that global warming on such a level could cause a rise in seawater levels and bring droughts that could affect the production of food and water supplies.
"This research shows that the regional impacts of a grand solar minimum are likely to be larger than the global effect, but it's still nowhere near big enough to override the expected global warming trend due to man-made change," Ineson said.
The British Met Office Hadley Centre-led study is featured in the journal Nature Communications.
Photo: NASA Goddard Space Flight Center | Flickr
