Researchers are reporting that Atlantic Ocean circulation is the weakest it has been in over 1500 years.
Why should that matter, and what does it mean for global climate change?
According to a new study published by climate scientists in the scientific journal Nature Geoscience, a current in the Atlantic Ocean that plays a key role in distributing heat throughout the planet’s entire ecosystem is moving more slowly now than has in at least 1600 year, perhaps even longer.
This should be cause for concern. Scientists believe that this slow down of the current is directly related to global warming. As worldwide temperatures rise, it leads to increased ice-melt in the northern waters. This alters ocean temperatures and the speed at which currents flow. Climatologists believe that the slowed Atlantic current is showing its impact in stronger storms, heatwaves, sea-level rise, and other unusual weather patterns that have been troubling over the last several years.
The authors of this most recent study say that this is just another flashing red light that if humans are not able to limit warming, the ocean current system could eventually reach a tipping point.
This would throw global climate patterns into complete disarray.
The Gulf Stream along the U.S. East Coast is an integral part of this system. It is known as the Atlantic Meridional Overturning Circulation, or AMOC. It was made famous in the 2004 film “The Day After Tomorrow,” in which the ocean current abruptly stops, causing immense killer storms to spin up around the globe, like a super-charged tornado in Los Angeles and a wall of water smashing into New York City. That may be a Hollywood over-dramatization. It is unlikely that the Gulf Stream would stop completely, but the concept in the film is valid, and it is indicative of what can happen if the critical current merely slows rather than stops completely.
According to the most recent data, the circulation has slowed down by at least 15% since 1950.
Scientists in the new study say the weakening of the current is “unprecedented in the past millennium.”
Because everything is connected, the slowdown is already having an impact on climate patterns. The researchers fear that if human-induced global warming is allowed to continue unchecked, the circulation may slow by close to 50% by the end of the century. Scientists fear that kind of slowdown would put us dangerously close to tipping points that could in some ways echo the fictitious devastation in the movie.
The lead author of the paper, Dr. Levke Caesar, said that the current slowdown of the AMOC is already reverberating in the climate system on both sides of the Atlantic. “As the current slows down, more water can pile up at the U.S. East Coast, leading to an enhanced sea-level rise [in places like New York and Boston],” she explained.
According to Caesar, these kinds of impacts and more will only worsen as the Earth continues to warm and the AMOC slows down more and more. As the current continues to slow, she says we can expect more extreme weather events like a change of the winter storm track coming off the Atlantic and potentially more intense storms, like those that recently devastated the state of Texas.