The Gulf Stream, the powerful warm current over the Atlantic Ocean, has not been so weak in a thousand years. This is what Irish, British and German climate scientists write in an article in the scientific journal Nature Geoscience. They fear that further weakening in Europe will lead to drier summers and harsher winters.
The researchers have collected and pooled as much available data and studies on the Gulf Stream for their studies. This ranges from analyses of deep-sea sediment and ice cores, to information about temperatures from ship logs.
Conveyor for climate
The ocean flow in the Atlantic is essential to the global climate. As a kind of “conveyor belt” for the climate, the Gulf Stream transports hot water from the equator from the Gulf of Mexico to the Arctic, in order to flow back cooled down.
Chief researcher Stefan Rahmstorf of the climate institute in Potsdam, Germany, showed in an earlier study that the current had become approximately 15 percent weaker in the second half of the last century.
“ This shows that the Gulf Stream remained relatively stable until the end of the 19th century. But towards the end of the Small Ice Age around 1850, the current became weaker, with a second, more drastic weakening since the mid-20th century,” says Rahmstorf in a press release.
No earlier weakness the flow in such a short time so quickly, the scientists say. Climate change caused by humans is the most likely cause, they think.
Oceanographer and climate scientist Erik van Sebille, associated with Utrecht University, describes the study as “a very short but clear story”. He didnt cooperate with the investigation.
Van Sebille: “There is no new data in it. Its just a nice overview of what we know now. Such a meta-analysis with the very latest insights can often be seen in, for example, medical science, but outside the UN climate panel IPCC, not in climate research. So thats why its good that this is there.”
The outcome does not surprise him. According to him, there were already several studies that identified a weaker Gulf Stream. He explains that the most recent IPCC report shows, for example, a world map showing temperature changes around the world.
“ Everything is almost red because it has become warmer, except for one blue area south of Greenland. This is one of the few places it has cooled down in the last hundred years, because the Gulf Stream brings less heat to it.”
CCEit on 3 made the following video about the last major climate report of the IPCC in 2019:
The ocean flow determines the mild sea climate in the Netherlands, wrote the KNMI in 2018. According to the Institute, if the current gets weaker, this can lead to “a long-term climate trend” with “uncertain” consequences for the Netherlands. In the research, the scientists will examine these possible consequences. They explain that further weakening of the Gulf Stream in Europe can lead to stricter winters and hotter, drier summers. In the US, there is a threat of a faster rise in sea level.
No Day After Tomorrow
Oceanographer Van Sebille says that it is still unclear how strong the weather in Europe will react to a weakening of the Gulf Stream. “But it will certainly not be The Day After Tomorrow,” he says, referring to the 2004 disaster film that deals with the consequences of climate change.
“ There is no doubt that the ocean has an important role in the climate as a buffer of heat and CO2, and also in redistributing that heat,” says the oceanographer. “And we know that temperature differences have a significant impact on the weather. So if the patterns in the ocean temperature change, the weather in Europe also changes. But how exactly that changes, we dont know. The speed at which the Gulf Stream weakens is only worrying.”
The study estimates that, based on the most recent climate models, the Gulf Stream decreased by around 35 percent around the year 2100. According to the researchers, this is “dangerously close” to the point at which the ocean flow becomes unstable.