© Getty Images

The ACC -

Around Earth’s southernmost and iciest continent, there flows an ocean current called the Antarctic Circumpolar Current (ACC).

© Shutterstock

Important function -

Although it receives less press than other ocean currents, such as the Gulf Stream, the ACC is very important for regulating the Earth’s temperature and pumping water, heat, and nutrients around the globe.

© Shutterstock

Relative stability -

Over recent decades, the strength of the ACC has remained relatively stable, despite expectations that warming water around Antarctica would speed it up.

© Shutterstock

New research -

New research shows, however, that the ACC could slow by up to 20% by 2050, due to the impact of global warming.

© Shutterstock

Far-reaching consequences -

Given the important role it plays in maintaining the global ecosystem, a weakening of the ACC could have profound consequences for life on Earth.

© Shutterstock

Strength of the ACC -

The ACC is the strongest ocean current on the planet. It is five times stronger than the Gulf Stream, and more than 100 times stronger than the Amazon River.

© Shutterstock

Moat around Antarctica -

This ocean current has been known to sailors for decades: forming a sort of moat around Antarctica, its flow facilitates ocean travel from west to east, and makes travel in the opposite direction very challenging.

© Shutterstock

Protecting the ice -

The ACC plays an important role in protecting Antarctica’s vulnerable ice sheets. By surrounding the continent, it keeps warm water at bay.

© Shutterstock

Barrier to invasive species -

It also acts as a barrier to invasive species, such as southern bull kelp. As these species drift towards Antarctica, the ACC helps spread them out.

© Shutterstock

Tricky location -

Although the ACC is the strongest ocean current on the planet, it is not that well understood. This is because its location makes obtaining direct measurements difficult.

© Shutterstock

Existing data -

Scientists do have data, however, to show that, until now, the strength of the ACC has remained relatively stable.

© Shutterstock

Despite predictions -

This is despite expectations that warming water around Antarctica would actually speed up the current.

© Shutterstock

Expectations -

In theory, it is density changes and winds around Antarctica that dictate the strength of the current, and since warm water is less dense, this should be enough to speed it up.

© Shutterstock

Reality -

New research shows, however, that, going forward, climate change may actually have a weakening effect on the ACC.

© Shutterstock

The research -

The new research involved ocean modeling using Australia’s fastest supercomputer and climate simulator in Canberra.

© Shutterstock

Ocean modeling -

The model was developed by a team of Australian researchers from various universities.

© Shutterstock

More accurate predictions -

The benefit of this new model is that it captures features that many previous models have missed. In this way, it offers more accurate predictions about how the ACC will change as the world warms.

© Shutterstock

The predictions -

The model predicts that as the planet continues to warm, the cold, fresh melt water from Antarctica will move northwards.

© Shutterstock

Major structural changes -

This freezing cold water will fill the deep ocean as it moves, causing major changes to the density structure of the ocean.

© Shutterstock

Key statistic -

The expectation is that this will counteract the effects of the ocean warming and cause a 20% slowdown of the ACC by 2050.

© Shutterstock

Far-reaching consequences -

If the ACC does in fact weaken by this much, it would have far-reaching consequences for both Antarctica and the rest of the planet.

© Shutterstock

Reduction of biodiversity -

A weakening of the current could mean a reduction of biodiversity, and therefore a softening of the fishing industry that many communities rely on.

© Shutterstock

Entry of invasive species -

A weaker ACC could also encourage the entry of invasive species, which would further disrupt local ecosystems and food webs.

© Shutterstock

More melting ice -

A weaker ACC may also mean that more warm water manages to travel southwards, exacerbating the problem of melting Antarctic ice.

© Shutterstock

Vicious circle -

Faster-melting ice may, in turn, lead to a further weakening of the current, causing a sort of vicious circle to form.

© Shutterstock

Poorer climate regulation -

And, ultimately, all of this disruption could extend to global climate patterns, which would reduce the ocean’s ability to regulate climate change by absorbing excess heat and carbon that ends up in the atmosphere.

© Shutterstock

Tackling the problem -

Although the findings of this new study are not promising, all is not lost when it comes to the future of the world’s strongest ocean current.

© Shutterstock

Reducing greenhouse gas emissions -

Indeed, experts believe that a concerted effort to reduce greenhouse gas emissions could still significantly limit ice melting around Antarctica.

© Shutterstock

Establishing studies -

Going forward, long-term studies must be established in the Southern Ocean so that researchers are properly able to track these changes.

© Shutterstock

Averting negative climate impacts -

With coordinated international action, we may still be able to avert the negative effects of climate change on our planet’s oceans and their currents.

Sources: (BBC) (Techno-Science.net) (Ocean Geographic Society)

See also: Scientist warns of changes in the Atlantic Ocean

© Shutterstock