What’s popularly known as the Gulf Stream, known by science as the Atlantic Meridional Overturning Circulation (AMOC), is part of a larger current that loops around the entire planet, moving massive quantities of heat from one place to another and affecting local climate effects everywhere. It’s the reason Ireland is warmer than Labrador, at the same latitude.
And without rapid reductions in greenhouse gas emissions, the continued melting of Arctic ice could cause it to break down.
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,” Hakai magazine reports, citing a study led by University of Bremen climate scientist Pepijn Bakker.
“It’s been often stated that Greenland melt could be very devastating for the AMOC, but no one has really looked at it in a systematic way,” Bakker said. Working with ocean and ocean/climate modellers, Bakker examined a variety of emission scenarios for their effects on the current.
On the current rate of increase in carbon emissions, “the AMOC has a 44% chance of collapsing entirely by 2300,” Hakai reports. On the other hand, “if anthropogenic carbon dioxide emissions peak around the year 2040 and then decline, the AMOC weakens by about 18%, but does not collapse.”
Were the Atlantic portion of the globe-circling current to weaken or shut down, Hakai writes, it would “cut off vast swaths of the ocean from a vital supply of heat and nutrients. Much of the planet could experience wild changes in temperature and productivity, altering entire ecosystems.”