Greenland Ice Melt Could Push Atlantic Circulation to Collapse
In the North Atlantic, east of North America and south of Greenland, the ocean’s upper layers are much warmer than one might presume given the extreme latitude. This unexpected warmth is a product of the Atlantic Meridional Overturning Circulation (AMOC), a vitally important system of ocean currents that moves warm salty water northward from the tropics and cold fresher water south. The AMOC looms large in the Earth’s climate: it is responsible for redistributing nutrients throughout the Atlantic Ocean and is a major driving force controlling the climate on both sides of the pond.
Ocean currents all experience fluctuations, which can dramatically change the distribution of nutrients, heat, and fish. The best known example is probably the El Niño-Southern Oscillation, in which unusually warm water occasionally disrupts the Pacific Ocean’s Humboldt Current that flows north from Chile toward Peru. El Niño events can shift the jet stream south, cause excessive rainfall and devastating floods, and temporarily collapse fish stocks.
To date, most climate research suggests that the AMOC is relatively stable and carries water throughout the ocean in a reliable, repeating cycle. But anthropogenic climate change seems to have made the current weaken slightly, raising the question of whether more dramatic shifts are in store. As of the most recent Intergovernmental Panel on Climate Change report, a shutdown of the circulation from further warming is considered unlikely. Yet a new study says that the unprecedented melting of Greenland’s massive ice sheets, previously overlooked in most climate modeling, will result in the AMOC weakening, and maybe even collapsing, within the next 300 years.
See the full article here.
From: Hakai Magazine
