Alan Zendell, Febru1ary 10, 2024

If you’re not familiar with the acronym AMOC, it’s the Atlantic Meridional Overturning Circulation, an ocean current that “works like a giant global conveyor belt, taking warm water from the tropics toward the far North Atlantic, where the water cools, becomes saltier and sinks deep into the ocean, before spreading southward.” If that description makes you wonder why you should care, I’ll add that the Gulf Stream, which keeps the climate in the northeastern part of North America from the mid-Atlantic to New Brunswick, Canada temperate, (habitable,) is part of the AMOC.

If the Gulf Stream stopped flowing, all of the eastern portions of the United States and Canada north of about 39 degrees latitude, roughly the Baltimore-Washington metropolitan area, would be covered with glaciers within a few years. Acclaimed science fiction writer Kim Stanley Robinson first addressed this in his 2005 trilogy, Science in the Capital. Long an advocate of finding ways to mitigate the effects of climate change, Robinson is not a doom-sayer. Rather he is a utopian who believes science will prevail in the end.

Scientists have long understood that AMOC and its child, the Gulf Stream, are sustained by the salinity of the Atlantic Ocean, particularly the North Atlantic and Arctic Oceans. Climate change is critical here, because rising global air and ocean temperatures are melting our polar icecaps. As the ice melts it turns to fresh water which decreases the salinity (the percentage of salt in the ocean water.) There is no scientific doubt that if this continues indefinitely, a tipping point will be reached at which the salinity has decreased by so much that these critical ocean currents collapse. What scientists have been unable to predict or calculate until now is how close we are to the tipping point and when we might reach it.

Recently, however, researchers at the University of Utrecht (Netherlands) used a supercomputer to run a sophisticated simulation of ocean currents, energy, temperature, and salinity, and for the first time, were able to simulate conditions that would result in a collapse of the Gulf Stream. They still cannot predict exactly when they might occur, but there’s little controversy over the consequences if they do.

Although Robinson, who has now published six books analyzing the future impact of climate change, is a science fiction writer, the possible collapse of the Gulf Stream is not science fiction. It’s hard, demonstrable science. In this era in which facts and science have become malleable in the hands of some politicians and educators, that’s a very serious matter. The collapse of the Gulf Stream would totally disrupt the world’s economy, its politics, and the ability of many industrial nations to survive.

The Utrecht study found that “[s]ome parts of Europe might see temperatures plunge by up to 30 degrees Celsius over a century … leading to a completely different climate over the course of just a decade or two.” To illustrate why, start by looking at average high temperatures in some of Europe’s major cities (slide right for later months.). They run in the mid-seventies Fahrenheit in summer to around forty in winter:

In North America, more than 100 million people would be displaced. Homes and jobs would disappear, food production would drop severely, and energy demands would skyrocket north of the 39^th parallel. Further south, the sunbelt would have to absorb all of the displaced families and businesses from up north. In Europe, whole nations would collapse, and a sudden shortage of critical resources would greatly increase the chances of major wars.

This isn’t the plot of a dystopian future novel or film, although it sounds like many of them. This is a real threat, and it may already be too late to avert it. Many people have denied climate change for political or financial reasons, or perhaps, because the consequences were too frightening or unbelievable to contemplate. If we don’t start taking it seriously and reduce carbon emissions and the global use of heat-generating fertilizers, the predictions above could become reality in our lifetimes.

A very smart person once told me it’s a really bad idea to piss-off Mother Nature. The only good news in all this is that the value of my Florida condo would soar, assuming Florida was still above water and money still had any value by then.