Its disappearance could make a large part of Europe uninhabitable. And it would have terrible consequences for the Atlantic Ocean and therefore for life on the planet.
Hello ecotrain friends, I hope you are very well, today I want to talk to you about something that if like me, you are of a certain age and you saw back in the 2000s the movie The Day After Tomorrow you will have some idea of what it is about, but unlike the movie, this is real, and it is happening right now. I'm talking about the disruption of the gulf stream, and the catastrophe it can generate.
But to understand a little bit first we need to cover a couple of basic concepts.
Like, for example, what are ocean currents?
Ocean currents are the displacement of large, huge amounts of water from the oceans in a particular direction, difficult to appreciate from the surface, their effect on life on the planet is crucial, these currents are generated by many, many factors, such as different temperatures in different regions of the planet, winds, salinity differences, the inertia of the earth's translational motion, the coriolis effect, a product of the planet's rotational motion, and even the variations of the gravitational force exerted by the moon on the seas, all of this also modified by the framework of the coastlines of islands and continents.
The different interactions between these primordial forces of nature in the moldable water create a very complex system of ocean currents as you can see in the cover image, which humans have been studying since the day our ancestors set sail in their primitive ships for the first time.
But this system of currents, although very complex and backed by such inexorable forces as gravity or the laws of thermodynamics, can also be a very fragile one...
The Gulf Stream.
This current originates in the Gulf of Mexico, and driven by westerly winds and temperature exchange, it flows off the coast of Florida, passes along the east coast of the United States, enters the North Atlantic where it crosses into the United Kingdom, the cost of western Europe and then northern Europe. It carries with it warmer, lower salinity, nutrient-rich waters from the tropical waters to the North Sea, and causes a flow of colder, more saline deep water to the south.
This current, the second most powerful in the world, has amazed navigators since the time of the discovery of America, since the first Spanish explorers noticed that, even with a good wind at their side, it was not possible to sail against the Gulf Stream.
The gulf stream moves in its origins 30 Sverdrups [the sverdrup is a measure used by oceanographers that equals 1 Million Cubic Meters of water PER SECOND] and as the different factors I mentioned are behind the currents, wind, temperature and salinity exchanges the power, reaches 150 Sverdrups. For a little more context, all the waters discharged by all the rivers in the Atlantic only add up to 0.6 Sverdrups.
This massive flow of warm waters northward from Europe changes the climate of the region tremendously, and is a major factor in creating the conditions necessary for human civilization to flourish in the region, since, with a more stable climate and more nutrients in the seas, humans were able to settle and thrive in regions so far north of the equator. For a practical example, let's say... Norway is north of the 69th parallel.
Another region north of the 69th parallel, but which does not have navigable seas year-round and is colder, is Siberia, because it does not have a current of warm nutrient-filled waters from the Caribbean regions off its coast.
The warm, moist winds that accompany the Gulf Stream are vital to the rain cycles in Europe, which allowed humans to establish large-scale agriculture in the region.
Basically, we could say that, without the Gulf Stream, vast portions of northern Europe would be as habitable to humans as Siberia, the northernmost regions of the Gorge, or Patagonia in Argentina. And surely, without the Gulf Stream, the great English, French or Low Countries civilizations would never have existed.
The gulf stream is disappearing?
It is not a speculation, in a study published by Nature magazine in 2018 a panel of scientists exposed that the gulf stream is at its lowest flow point in the last 1600 years. But... because9 although in 2018 when the study was published it wasn't clear, now it is....
https://www.nature.com/articles/d41586-018-04086-4
Climate change
Rising global temperatures, along with higher levels of radiation passing through the weakened ozone layer and the effect of greenhouse gases are melting the poles, when the great ice sheets at the north pole melt they pump large flows of water warmer than that in the sea, and with much lower levels of salinity than that in the sea to the east, This water, thanks to its lower density and higher temperature, moves through layers closer to the surface, where it collides with the quality, low-salinity water coming in the Gulf Stream, interrupting the process of exchange of cold, salty water from the northern sea depths with the warm, less salty water coming from the south.
This generates a whole set of problems, disrupting weather patterns, damaging marine ecosystems, and accelerating the effects of global warming in a kind of domino effect that can, at first, destroy agriculture and fisheries in northern Europe, and at an extreme point, incredible as it may seem, trigger a new ice age?
Not as dramatic as The Day After Tomorrow [a decent movie that I recommend watching, but see it as that, as a movie, a work of fiction] but it would be disastrous for human life on the planet...
Not only Europe would be affected, the oceans are an interconnected system, so the consequences will be felt all over the world, a serious example is the dramatic reduction of biodiversity, since the water exchange regions are the breeding ground for microorganisms that sustain life on the planet, if these are reduced, the krill for example will run out of food, and then the fish ... and then everything else.
Although scientists have no exact way to measure the point of collapse of the currents due to the large number of factors that influence and the unpredictability of the climate, [for example a heat wave in Siberia can generate fires that pump gratuities of Co2 into the atmosphere at times that nobody can predict].
They recommend the world to try to reduce Co2 emissions by all possible methods, and warn that humanity has already crossed several of the points of no return to avoid a climate catastrophe, but that this one, which we are close to crossing, is one of those that will have the most terrible consequences.
Undoubtedly a testimony of the tremendous capacity of humanity to alter the planet's climate, unfortunately in this case for the worse... the change of currents is an existing threat for humanity as a species, let's hope that this point of no return is not exceeded. I don't want to end up like those in that 2003 movie.
Recommended Bibliographic Reference
[1] THOSE ALOANS OF ROM BORROWERS/a>
[3] climate crisis scientists spot warning signs of gulf stream collapse/a>