Iceland Declares Ocean-current Instability A National Security Risk

Iceland’s relatively mild climate is shaped by a crucial network of currents that winds its away around the Atlantic Ocean transporting heat northward — without it, the island would be much icier and stormier. As evidence mounts these currents could be on course for collapse, Iceland’s government has made the unusual move of designating the risk a national security threat, prompting a a high-level response into how to prepare for this “existential threat.”

“Our climate, economy and security are deeply tied to the stability of the ocean currents around us,” said Jóhann Páll Jóhannsson, Iceland’s Minister for Environment, Energy and Climate.

The Atlantic Meridional Overturning Circulation — known as the AMOC — is a looping system of currents that works like a giant conveyor belt, pulling warm water from the Southern Hemisphere and tropics to the Northern Hemisphere, where it cools, sinks and flows back south.

When scientists are asked which potential climate impact terrifies them most, the collapse of the AMOC is often top of the list.

A growing body of research points to the AMOC slowing down, as higher global temperatures disrupt the delicate balance of heat and salinity on which its strength relies. The science is still unsettled on the likelihood and timing of any collapse, but some studies have projected it could be on course to happen this century.

A shutdown of the AMOC “cannot be considered a low likelihood risk anymore in view of the evolving science over the past years,” said Stefan Rahmstorf, a physical oceanographer and climatologist who has studied the AMOC at Potsdam University in Germany.

Scientists mapped what happens if a crucial system of ocean currents collapses. The weather impact would be extreme

The impacts would be catastrophic — ushering in huge global weather and climate shifts, including rising sea levels in parts of the US and Europe, disrupted monsoon systems affecting countries in Asia and Africa, and a winter deep freeze in Europe, with sea ice potentially creeping southward as far as the United Kingdom.

Iceland “would be close to the center of a serious regional cooling,” meaning the country could be surrounded by sea ice, Rahmstorf told CNN.

It’s an “an existential threat,” Jóhannsson told CNN. The AMOC regulates Iceland’s weather, and its collapse could devastate infrastructure, transport and vital industries including fishing, he said.

Source: HackerNews