Two new climatological studies are warning about the potential for a scenario similar to what was depicted in Whitley Strieber and Art Bell’s book ‘The Coming Global Superstorm’. Both studies investigate the potential impact of freshwater from melting ice from the Arctic and Greenland: one focusing on the potential future impacts, and the other, how the deep past was affected by the same conditions.
The first study, from the Alfred Wegener Institute in Germany, used computer modeling to determine the effect that a rapid thaw of Greenland’s glaciers, of which would dump massive amounts of fresh water into the North Atlantic, would affect the Atlantic’s currents.
“Previous studies have generally had to estimate the amount of melting and then insert the meltwater into the ocean simulation by hand, or haven’t included the feedback between ice sheet melting and ocean salinity at all,” according to lead scientist Paul Gierz. His computer model is predicting a 7% drop in ocean salinity in the region south of Greenland.
Ordinarily, as the water in the northern current cools as it approaches the European coast, it descends to lower depths, to be re-circulated back towards the south. Typically, an increase in the amount of cool water would increase the operation of this mechanism. However, the glacial meltwater is made up of fresh water, causing a drop in the density of the seawater that it mixes with. This keeps the water buoyant, and prevents it from descending back to the lower currents, slowing — and potentially stopping — the operation of the entire system.
Gierz also warns that the full impact of these changes mightn’t be felt for decades, due to the sheer size of the environmental system involved. “Even if we shut off all greenhouse-gas emissions tomorrow morning, the climate system would continue to adapt to the already incurred perturbations. However, the more we — as a society — do proactively right now, the less we will have to do reactively later on.”
A second study, from the University of Texas Institute of Geophysics, investigated how the Earth’s climate responded to similar conditions at the end of the last ice age, 12,000 years ago. What they found was that as temperatures rose, the massive influx of fresh water pouring into the oceans disrupted ocean currents enough to impact global climatological patterns, rapidly plunging northern regions into another ice age, called the Younger Dryas, while other regions on the other side of the planet experienced massive, long-term droughts.
The study’s lead author, Jud Partin, remarks: “A slowdown of the ocean circulation is a double-edged sword. If we see some temperature changes associated with it … and somehow are quick to act and alleviate the change, then we have the potential to stop it.”
There is substantial evidence, which is detailed in "Superstorm," that in the past the climate shift that resulted from the collapse of the system unfolded over a single season and lasted until the system was restored as ocean salinity once again rose as the melt dissipated. The last time this happened, it was due to the release of a massive amount of ice that had become trapped in the St. Lawrence Seaway in Canada. This time, salinity is dropping because of the rapid Greenland melt.
The image is from the film "The Day After Tomorrow" which is based on "Superstorm."