We may not be literally running from the snow like in the 2004 film “The Day After Tomorrow”, but Earth might be on the way to experiencing the plot of the film in the future, according to two new studies.
Both of these studies are related to Atlantic Meridional Overturning Circulation (AMOC). That’s the “Atlantic component of the global ocean conveyor belt, a large-scale ocean circulation system that carries heat, salt, carbon, and other biogeochemical elements along its paths,” explained the Atlantic Oceanographic Meteorological Laboratory. This conveyor belt is driven by saltiness and ocean temperature.
According to the lab, the climate models “suggest that the anthropogenic weakening of the AMOC has been happening since the mid-1980s,” though they also show that the AMOC is resilient. Since the AMOC brings “warmth to various parts of the globe and also carries nutrients necessary to sustain ocean life,” as noted by the National Oceanic and Atmospheric Administration, changes to it can cause concern.
In “The Day After Tomorrow” the AMOC collapses in just days, triggering extreme cold. In real life, that would be impossible, the National Oceanography Center in the U.K. said.
Impacts from a change to the AMOC might not be as dramatic or fast, but one of the recent studies said data suggests that the AMOC could be headed towards an eventual collapse. According to that research, published April 16 in the Science Advances journal, the AMOC is expected to weaken by 50% by 2100, potentially leading to a total collapse.
A study published in the same journal on April 8 showed that the AMOC had already been weakening over the past 20 years at four different locations. It said “this decline, observed at the western boundary, may serve as an effective indicator of AMOC weakening, despite the partial compensatory effect of overturn strengthening at the eastern boundary.”
What does this all mean?
“In a sense, observations at the western boundary, in isolation from the eastern boundary, constitute the canary in a coal mine for the tendency of the AMOC,” study co-author Shane Elipot told USA Today via email. “These findings support the evidence of a broader weakening of the AMOC.”
Authors of the April 16 study also said that their projections for AMOC weakening were around 60% stronger than that estimated by the average of all climate models, due to calculation corrections. With AMOC weakening, we can expect climate changes.
Elipot told USA Today that it could lead to cooler temperatures over the North Atlantic Ocean, more winter storms in Europe and a reduction in Sahelian and South Asian summer rainfall. He also said that it could cause the sea level on the American northeast coastline to rise more sharply.
There are ways to mitigate the weakening AMOC, Elipot said. He told USA Today that it is attributed mostly to climate change, explaining that global warming events can prevent the usual sinking of dense, cold water in the North Atlantic, thus impacting water density and circulation of saltwater and freshwater.
According to Elipot, reducing carbon dioxide emissions and transitioning to clean energy could help mitigate the impacts of climate change. He also said ongoing observation and research of AMOC is important.
