ARCTIC IRELAND
Fears sea change will submerge country ‘Our winters would be like Scandinavia...’
IRELAND will face bleak winters covered in Arctic ice if the collapse of the planet’s ocean systems comes to pass, scientists have warned.
Parts of the island could be under water with a sea level rise of 2ft and a 15C temperature drop predicted unless climate change warnings are heeded.
Boffins sound the alarm in a new report that the Atlantic Meridional Overturning Circulation, or AMOC, which shunts warm and cold water between the poles like a conveyor belt, is “on course” to a tipping point.
Radical shifts in the planet’s climate will result – with the Amazon rainforest’s seasons flipped – if the AMOC seizes due to increasing flows from melting ice sheets.
Ireland would be one of the most severely affected according to climate and physics researcher Rene van Westen, co-author of the research published in Science Advances.
He said: “Based on the temperature trends and coastal areas, I would say that northwestern Europe – Ireland, UK, Belgium, Netherlands, Denmark, Norway, Sweden – are mostly affected under a potential AMOC collapse.
“Winter temperatures would go down by about 15C. Ireland would be covered by the Arctic sea ice pack during the winter.
“The expected sea level rise due to an AMOC collapse is about 70cm of sea-level rise around Ireland.”
Van Westen believes the collapse would see Ireland experience a “Scandinavian-like climate...in particular for the winter months”.
As the planet warms, melting glaciers and ice sheets are disrupting traditional patterns adding more freshwater to
the system which dilutes its salinity.
“The AMOC is driven by ocean density differences. Warm and fresh water is relatively light, while cold and saline water is relatively heavy,” explained Dr van Westen.
“The heaviest water is found around Greenland, which is cold and saline, and sinks to greater depth, this partly determines the AMOC strength.
“Under climate change, the waters around Greenland become warmer and fresher due to melting of the ice sheet, this reduces the sinking hence affecting the AMOC strength.”
Researchers used a supercomputer to carry out highly sophisticated modelling, finding that a slow decline could eventually lead to a sudden collapse over less than 100 years. The paper is the first to demonstrate that the AMOC can reach a tipping point if enough freshwater is added.
“We cannot deduce when the AMOC would tip, we can only indicate that we are moving closer to the tipping point.”
He added: “The AMOC is a full 3D circulation covering the entire Atlantic Ocean, it is like a conveyor belt in the Atlantic Ocean.
“The Gulf Stream is part of the upper branch of AMOC.”
He said climate change and the collapse of the AMOC could have differing effects.
“Under global climate change, we expect an increase of the surface temperatures,” he added.
“An AMOC collapse would, partly, mask this temperature increase, so your temperature response is a combination of climate change and Amoc-induced responses.
“Some regions cool stronger under an AMOC collapse than the induced global warming trend, these regions may experience cooling even when the global climate further warms.”
He said urgent climate action is needed to avoid such a potential AMOC collapse. Dr van Westen added: “Policy makers around the world need to mitigate our global emissions to prevent further warming and limit the risk of AMOC tipping and other tipping elements.”
Ireland would be covered by Arctic ice during the winter
North-west Europe and Ireland would be the most affected