New research suggests that ocean circulation in the North Atlantic is now the weakest that it is has been in around 1,500 years, which could have profound implications on the future climates of North America and Europe.
According to the Daily Mail, the churning of water in the North Atlantic has now “dramatically weakened,” which could spell trouble very soon, and this trouble was recently brought to light by scientists who have been closely observing the Atlantic Meridional Overturning Circulation (AMOC).
The AMOC is the circulation of the North Atlantic that carries with it warmer waters up to the Arctic and also moves much colder water near the equator. The new research on the circulation of the North Atlantic was conducted by Drs. Christelle Not and Benoit Thibodeau, who work at the Department of Earth Sciences and the Swire Institute of Marine Science, The University of Hong Kong.
This dramatic changing of the ocean circulation in the North Atlantic is believed to be caused by global warming, which has contributed greatly to the Greenland Ice-Sheet and its melting. With slower circulation in the North Atlantic also comes a profound change in the respective climates of both North America and Europe, yet also affects Asia and Africa with regard to heavier monsoons during the summer.
Ocean circulation in North Atlantic is at its weakest for 1,500 years - and at levels that previously triggered a mini Ice Age, study warns. Similar weak signal during a period called the Little Ice Age, a cold spell observed between about 1600 and 1850 AD https://t.co/B1h4dcKbRb pic.twitter.com/cYdJB7iwz3— Climate Realists (@ClimateRealists) November 26, 2018
As Dr. Thibodeau explained, the AMOC has the ability to help scientists learn more about the many changes that take place because of global warming.
“The AMOC plays a crucial role in regulating global climate, but scientists are struggling to find reliable indicators of its intensity in the past. The discovery of this new record of AMOC will enhance our understanding of its drivers and ultimately help us better comprehend potential near-future change under global warming.”
Scientists have been able to sort through data and have found that the last time circulation in the North Atlantic was as slow as it is today, the Little Ice Age occurred between 1600 and 1850 AD. However, a larger view of this shows that the entirety of the Little Ice Age really lasted from 1300 to 1850 AD and occurred in two distinct waves.
The start of the Little Ice Age actually began in 1290 and lasted until the latter period of the 1400s. While things warmed up slightly during the 1500s, things cooled down again dramatically between the years 1645 and 1715, with temperatures believed to be two degrees Celsius cooler than they are now on average in North America and Europe.
However, to suggest that slower circulation in the North Atlantic was the definitive cause of this Little Ice Age will require further analysis, according to Dr. Not.
“While we could ground-truth our temperature reconstruction for the 20th century against instrumental measurement it is not possible to do so for the Little Ice Age period. Therefore, we need to conduct more analysis to consolidate this hypothesis.”
With further study of the AMOC and the weakened North Atlantic circulation, researchers will be able to better determine whether this slowing down could help to trigger another Little Ice Age again in the future.