AMOC: An Ambitious Strategy to Preserve Vital Ocean Currents Using Giant Parachutes

Strategies to uphold the current involve oversized versions of parachute-like ocean anchors

Ed Darnen (2.0 by CC)

As part of an ambitious initiative to avert severe climate change, large parachutes could be deployed into Atlantic waters using transport tankers, drones, and fishing vessels.

The Atlantic Meridional Overturning Circulation (AMOC) moves warm water from the tropics northward and helps stabilize temperatures in Northern Europe.

Nevertheless, the swift melting of Arctic ice and rising sea temperatures have hampered these currents, prompting some scientists to warn that they could falter entirely within this century. Such an event would disrupt marine ecosystems and exacerbate the cooling of the European climate.

Experts emphasize the urgent need to cut greenhouse gas emissions to mitigate the risk of AMOC collapse and other catastrophic climate “tipping points.” However, some are exploring alternative, more fundamental methods to preserve the current.

Stuart Haszeldine from the University of Edinburgh, along with David Sevier, introduced a concept from the British water treatment firm Strengite during a recent meeting in Cambridge, UK. They propose utilizing just 35 ocean tugs, each capable of pulling underwater parachutes roughly half the size of a soccer pitch, which could effectively move enough water to maintain the current. “A modest amount of energy and equipment can yield a significant impact,” Haszeldine remarks.

These parachutes, designed similarly to existing ocean anchors, stabilize containers in rough weather while also aiding in water movement across the sea surface. Each parachute features a central hole 12 meters wide to allow marine creatures to escape.

The operation would run 365 days a year in a rotating schedule, using drones, transport tankers, tugs, or wind kits. “It’s a small but consistent intervention,” notes Haszeldine.

Sevier refers to this proposal as “any Mary,” indicating a solution to stave off the severe consequences of AMOC collapse. “This is about buying time,” he asserts, emphasizing the need for the world to reduce emissions sufficiently to stabilize global temperatures at safe levels.

However, leading AMOC researchers express skepticism about the idea. Rene van Westen from the University of Utrecht, Netherlands, highlights that the density differences between cold, salty water and warm, fresh water play a crucial role in the descent and upwelling movements that sustain AMOC.

“If this idea is to work,” Van Westen argues, “you can only use surface wind to influence the top layer of water.

Stephen Rahmstoef from the Potsdam Institute for Climate Impact Research concurs. “The challenge lies not in moving surface water horizontally but in sinking it to depths of 2,000 to 3,000 meters and returning it south as a cold, deep current,” he states.

Meric Srokosz of the UK National Oceanography Centre believes the proposal is “unlikely to succeed,” given the variable weather conditions that complicate equipment deployment in the oceans.

Haszeldine welcomes feedback from fellow scientists regarding the proposal and hopes it will inspire ocean and climate modelers to assess the ecological and environmental ramifications of the plan. “I believe this warrants further investigation,” he asserts.

More generally, Haszeldine argues for increased research focused on climate intervention strategies to sustain ocean circulation: “I don’t see anyone else working on ocean currents.”

topic:

Source: www.newscientist.com