Climate scientists have discovered an early warning that the North Atlantic Gulf Stream – which protects Ireland’s mild climate – may already be irreversibly disrupted.
p Until now, the oceans have protected us from the worst effects of climate change because they absorb 25 percent of all carbon dioxide greenhouse gas emissions and 90 percent of the excess heat attributed to those emissions.
“We know that oceans and climate can change abruptly, and we call the times when this happens ‘tipping points,'” said Professor Gerard McCarthy, who was involved in the research.
“There is concern that a tipping point is approaching in the North Atlantic and Ireland that would likely result in drier summers and wetter, more stormy winters,” Prof McCarthy said.
That’s bad enough, but another, less likely, but still possible, outcome is that there could be a breakdown in the normal ocean currents that circulate in the North Atlantic, particularly the Gulf Stream.
If that happens, it could lead to huge temperature drops or even trigger a new ice age.
An international team of climate scientists based in the Netherlands, France, Spain and Ireland came together to analyze the available scientific data on climate variability in the North Sea over the past 1,000 years.
“We used artificial intelligence and machine learning computer models to examine past data from a range of sources,” said Prof McCarthy of the Irish Climate Research and Analysis Unit (ICARUS) at Maynooth University.
“We found a signal in the data that looks like a warning sign that a period of abrupt change in the North Atlantic is approaching.”
He added: “In the Atlantic, sea surface temperatures are either slightly warmer or slightly colder than usual. If you go back to the sixties and seventies, the Atlantic was a little colder than usual.
“There’s a natural variability in the data between times when the Gulf Stream is strong and times when it’s not as strong,” Prof McCarthy said.
“We found that tipping points occurred when the gaps between wobbles began to lengthen, and that’s what we’re seeing in the data now.”
He said the study adds to growing evidence that changes may already be underway in the Gulf Stream system, on which Ireland’s climate depends.
“It emphasizes the importance of gaining a better understanding of this critical element of the climate system so that we can prepare for the future.”
Professor Simon Michel from the Institute for Marine and Atmospheric Research in Utrecht led the research, which was published in nature communication.
But even if the climatic turning point in the Atlantic has now been reached, according to Prof. Michel, we should not give up on reducing our emissions.
“Because we have caused or are about to cause irreversible changes in the climate system, measures to adapt to climate change are now as important and necessary as measures to mitigate climate change,” said Prof. Michel.
https://www.independent.ie/news/environment/changes-in-gulf-stream-at-tipping-point-that-could-alter-irelands-weather-dramatically-41963768.html Gulf Stream changes at ‘tipping point’ that could dramatically change Ireland’s weather