The Atlantic Meridional Ocean Circulation (AMOC), a system of currents that warm Europe, is at risk of collapsing in the near future. Global warming caused by excessive CO2 emissions has slowed the current down, and if it totally collapses, it could release massive amounts of carbon from deep in the ocean into the atmosphere, creating a loop that would only continue to warm the earth.
Previous research has already shown that if the AMOC were to collapse, it would disrupt monsoon patterns in Africa and Asia, cause record-setting cold winters across all of Europe and raise global temperatures.
However, new computer models predict additional disruptions from the shutdown of the current: the release of 640 billion tonnes of carbon dioxide into the atmosphere. This massive amount of carbon emissions would increase global temperature by about 0.2°C.
The AMOC is powered by differences in water density, and warms water from the Gulf of Mexico to the northern Atlantic Ocean. From there, it sinks as it cools in temperature and eventually makes its way back to the gulf along the seafloor, creating a cycle. Scientists believe that freshwater that has melted from Greenland’s ice sheets is disrupting the flow as it slows down the process of sinking.
Buoys that monitor ocean currents have recorded data that suggest the return flow to the gulf has already weakened, lowering the productivity of the AMOC by around 15 per cent. With this information, models have projected the collapse of the current to occur anywhere from decades to centuries from now.
While the collapse is not projected to happen for a long time, the continued release of CO2 emissions from current human activities will only speed up the process, leading to a collapse that will cause irreversible damage.
The collapse of the AMOC is predicted to drop arctic temperatures, freezing parts of Russia, Canada and Scandinavia. In addition, it could also trigger the collapse of the East Antarctic Ice Sheet, which would expel tonnes of water into the ocean, massively increasing water levels and having major effects on life around the world.
