New research shows that the circulation of the Atlantic Ocean is at it weakest level in 1,600 years, which could disrupt weather patterns in the United States, Europe, and Africa.
This low circulation is an effect of climate change and could be catastrophic.
A new study published in Nature by the University College London and the Woods Hole Oceanographic Institution shows that the Atlantic Ocean circulation system that cools warm ocean water hasn't been at its peak since the mid-1800s.
The Atlantic Ocean is responsible for carrying warm water into the Northern Hemisphere. Circulation of the Atlantic Ocean declined 15 percent since the mid-20th century. That would be a decrease of 3 million cubic meters of water per second.
The Atlantic Ocean is part of what is called the Global Ocean Conveyor Belt. This system sends warm, salty Gulf Stream water to the North Atlantic, which releases heat into the atmosphere warming Western Europe. This makes colder water towards the bottom of the ocean and reaches Antarctica.
According to a co-author of the study, Dr. Delia Oppo, this survey is the first investigation that shows how the Atlantic Ocean's circulation has been slowing down.
Scientists believe that the Atlantic Meridional Overturning Circulation (AMOC) was first disrupted at the end of the Little Ice Age, which was a cool period on Earth that lasted until around 1850, by freshwater. This was caused by the Arctic sea ice, ice sheets, and glaciers melting, which diluted surface seawater and made it harder for it to sink, causing the whole system to slow down.
Second Study On AMOC
A second study released in Nature reveals that AMOC has been slowing down more quickly since the 1950s due to climate change. The study was led by Levke Ceasar and Stefan Rahmstorf from the Potsdam Institute for Climate Impact Research. They analyzed past sea surface temperatures to determine their findings.
They also used sediment samples from the ocean near Cape Hatteras, North Carolina. This helped them determine how strong the circulation was more than a thousand years ago. They were able to determine that the current slowed down around 160 to 170 years ago by examining the size of the sand grains. The stronger the current, the bigger the sand grains it can push.
Scientists on the first study came to the conclusion that this change could be natural or could be due to climate change caused by humans.